diff --git a/modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/CompletionCommand.java b/modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/CompletionCommand.java
index bd67596fa9bf292fceeec9aa7e8942d6e2ad31c3..85bbba57e0ce375e1c29e8b6dc628149526b383a 100644
--- a/modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/CompletionCommand.java
+++ b/modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/CompletionCommand.java
@@ -86,7 +86,7 @@ public class CompletionCommand extends OpenApiGeneratorCommand
                         null,
                         suggesterMetadata.getMetadataInjections(),
                         bindings.build(),
-                        new DefaultCommandFactory<Suggester>());
+                        new DefaultCommandFactory<>());
 
                 return suggester.suggest();
             }
@@ -99,4 +99,4 @@ public class CompletionCommand extends OpenApiGeneratorCommand
     void execute() {
         System.out.println(Joiner.on("\n").join(generateSuggestions()));
     }
-}
\ No newline at end of file
+}
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CliOption.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CliOption.java
index 6851f0cb5fefdecee71c857bf9fb68f5eb95ea9e..2ed4d7a350c4230985cad9c42e484a4c4c6b30ad 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CliOption.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CliOption.java
@@ -88,7 +88,7 @@ public class CliOption {
 
     public CliOption addEnum(String value, String description) {
         if (this.enumValues == null) {
-            this.enumValues = new LinkedHashMap<String, String>();
+            this.enumValues = new LinkedHashMap<>();
         }
         if (!enumValues.containsKey(value)) {
             enumValues.put(value, description);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java
index 6c552a97b80623eecb393bb56c50d9a384680dd1..d930454bc23e276ddddfde4c5b543290909dd9e7 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java
@@ -51,7 +51,7 @@ public class CodegenConfigLoader {
 
     public static List<CodegenConfig> getAll() {
         ServiceLoader<CodegenConfig> loader = ServiceLoader.load(CodegenConfig.class, CodegenConfig.class.getClassLoader());
-        List<CodegenConfig> output = new ArrayList<CodegenConfig>();
+        List<CodegenConfig> output = new ArrayList<>();
         for (CodegenConfig aLoader : loader) {
             output.add(aLoader);
         }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
index ab9f23fba6757637ae818cc22866395f7feedf22..f97c47217773e18726bed55b0b4ba26e602edf9f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
@@ -45,9 +45,9 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public List<CodegenModel> children;
 
     // anyOf, oneOf, allOf
-    public Set<String> anyOf = new TreeSet<String>();
-    public Set<String> oneOf = new TreeSet<String>();
-    public Set<String> allOf = new TreeSet<String>();
+    public Set<String> anyOf = new TreeSet<>();
+    public Set<String> oneOf = new TreeSet<>();
+    public Set<String> allOf = new TreeSet<>();
 
     // anyOf, oneOf, allOf with full properties/tags (e.g. isString, etc)
     public List<CodegenProperty> anyOfProps = new ArrayList<>();
@@ -71,20 +71,20 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean isAlias; // Is this effectively an alias of another simple type
     public boolean isString, isInteger, isLong, isNumber, isNumeric, isFloat, isDouble, isDate, isDateTime, isShort, isUnboundedInteger, isBoolean;
     private boolean additionalPropertiesIsAnyType;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
-    public List<CodegenProperty> allVars = new ArrayList<CodegenProperty>(); // all properties (with parent's properties)
-    public List<CodegenProperty> requiredVars = new ArrayList<CodegenProperty>(); // a list of required properties
-    public List<CodegenProperty> optionalVars = new ArrayList<CodegenProperty>(); // a list of optional properties
-    public List<CodegenProperty> readOnlyVars = new ArrayList<CodegenProperty>(); // a list of read-only properties
-    public List<CodegenProperty> readWriteVars = new ArrayList<CodegenProperty>(); // a list of properties for read, write
-    public List<CodegenProperty> parentVars = new ArrayList<CodegenProperty>();
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
+    public List<CodegenProperty> allVars = new ArrayList<>(); // all properties (with parent's properties)
+    public List<CodegenProperty> requiredVars = new ArrayList<>(); // a list of required properties
+    public List<CodegenProperty> optionalVars = new ArrayList<>(); // a list of optional properties
+    public List<CodegenProperty> readOnlyVars = new ArrayList<>(); // a list of read-only properties
+    public List<CodegenProperty> readWriteVars = new ArrayList<>(); // a list of properties for read, write
+    public List<CodegenProperty> parentVars = new ArrayList<>();
     public Map<String, Object> allowableValues;
 
     // Sorted sets of required parameters.
-    public Set<String> mandatory = new TreeSet<String>(); // without parent's required properties
-    public Set<String> allMandatory = new TreeSet<String>(); // with parent's required properties
+    public Set<String> mandatory = new TreeSet<>(); // without parent's required properties
+    public Set<String> allMandatory = new TreeSet<>(); // with parent's required properties
 
-    public Set<String> imports = new TreeSet<String>();
+    public Set<String> imports = new TreeSet<>();
     public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, hasValidation;
     /**
      * Indicates the OAS schema specifies "nullable: true".
@@ -109,7 +109,7 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean hasOnlyReadOnly = true; // true if all properties are read-only
     public ExternalDocumentation externalDocumentation;
 
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
 
     /**
      * The type of the value for the additionalProperties keyword in the OAS document.
@@ -1056,13 +1056,13 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
 
     private List<CodegenProperty> removeDuplicatedProperty(List<CodegenProperty> vars) {
         // clone the list first
-        List<CodegenProperty> newList = new ArrayList<CodegenProperty>();
+        List<CodegenProperty> newList = new ArrayList<>();
         for (CodegenProperty cp : vars) {
             newList.add(cp.clone());
         }
 
-        Set<String> propertyNames = new TreeSet<String>();
-        Set<String> duplicatedNames = new TreeSet<String>();
+        Set<String> propertyNames = new TreeSet<>();
+        Set<String> duplicatedNames = new TreeSet<>();
 
         ListIterator<CodegenProperty> iterator = newList.listIterator();
         while (iterator.hasNext()) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenOperation.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenOperation.java
index 0a8e7b31991c45c64551617c283b7edbdc8d0d78..f4fcd1f17adcdce1f004393ed6c2684a9c67a437 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenOperation.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenOperation.java
@@ -23,7 +23,7 @@ import io.swagger.v3.oas.models.tags.Tag;
 import java.util.*;
 
 public class CodegenOperation {
-    public final List<CodegenProperty> responseHeaders = new ArrayList<CodegenProperty>();
+    public final List<CodegenProperty> responseHeaders = new ArrayList<>();
     public boolean hasAuthMethods, hasConsumes, hasProduces, hasParams, hasOptionalParams, hasRequiredParams,
             returnTypeIsPrimitive, returnSimpleType, subresourceOperation, isMap,
             isArray, isMultipart,
@@ -34,26 +34,26 @@ public class CodegenOperation {
             returnContainer, summary, unescapedNotes, notes, baseName, defaultResponse;
     public CodegenDiscriminator discriminator;
     public List<Map<String, String>> consumes, produces, prioritizedContentTypes;
-    public List<CodegenServer> servers = new ArrayList<CodegenServer>();
+    public List<CodegenServer> servers = new ArrayList<>();
     public CodegenParameter bodyParam;
-    public List<CodegenParameter> allParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> bodyParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> pathParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> queryParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> headerParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> formParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> cookieParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> requiredParams = new ArrayList<CodegenParameter>();
-    public List<CodegenParameter> optionalParams = new ArrayList<CodegenParameter>();
+    public List<CodegenParameter> allParams = new ArrayList<>();
+    public List<CodegenParameter> bodyParams = new ArrayList<>();
+    public List<CodegenParameter> pathParams = new ArrayList<>();
+    public List<CodegenParameter> queryParams = new ArrayList<>();
+    public List<CodegenParameter> headerParams = new ArrayList<>();
+    public List<CodegenParameter> formParams = new ArrayList<>();
+    public List<CodegenParameter> cookieParams = new ArrayList<>();
+    public List<CodegenParameter> requiredParams = new ArrayList<>();
+    public List<CodegenParameter> optionalParams = new ArrayList<>();
     public List<CodegenSecurity> authMethods;
     public List<Tag> tags;
-    public List<CodegenResponse> responses = new ArrayList<CodegenResponse>();
+    public List<CodegenResponse> responses = new ArrayList<>();
     public List<CodegenCallback> callbacks = new ArrayList<>();
-    public Set<String> imports = new HashSet<String>();
+    public Set<String> imports = new HashSet<>();
     public List<Map<String, String>> examples;
     public List<Map<String, String>> requestBodyExamples;
     public ExternalDocumentation externalDocs;
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     public String nickname; // legacy support
     public String operationIdOriginal; // for plug-in
     public String operationIdLowerCase; // for markdown documentation
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java
index ebd01afdfd243c0f58ce94c01fff77c625a36a8b..85da2f96354b6015c2d652a5126700e60a7d7a62 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java
@@ -45,10 +45,10 @@ public class CodegenParameter implements IJsonSchemaValidationProperties {
     public Map<String, Object> allowableValues;
     public CodegenProperty items;
     public CodegenProperty additionalProperties;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
-    public List<CodegenProperty> requiredVars = new ArrayList<CodegenProperty>();
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
+    public List<CodegenProperty> requiredVars = new ArrayList<>();
     public CodegenProperty mostInnerItems;
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     public boolean hasValidation;
     public boolean isNullable;
     public boolean isDeprecated;
@@ -160,10 +160,10 @@ public class CodegenParameter implements IJsonSchemaValidationProperties {
         output.setHasDiscriminatorWithNonEmptyMapping(this.hasDiscriminatorWithNonEmptyMapping);
 
         if (this._enum != null) {
-            output._enum = new ArrayList<String>(this._enum);
+            output._enum = new ArrayList<>(this._enum);
         }
         if (this.allowableValues != null) {
-            output.allowableValues = new HashMap<String, Object>(this.allowableValues);
+            output.allowableValues = new HashMap<>(this.allowableValues);
         }
         if (this.items != null) {
             output.items = this.items;
@@ -178,7 +178,7 @@ public class CodegenParameter implements IJsonSchemaValidationProperties {
             output.mostInnerItems = this.mostInnerItems;
         }
         if (this.vendorExtensions != null) {
-            output.vendorExtensions = new HashMap<String, Object>(this.vendorExtensions);
+            output.vendorExtensions = new HashMap<>(this.vendorExtensions);
         }
         output.hasValidation = this.hasValidation;
         output.isNullable = this.isNullable;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java
index ed1636fc6d53fb920d3aacbcc94b1a36d5cd5550..defc454df2a1585a6da0ae7d45ef85256b43907c 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java
@@ -162,10 +162,10 @@ public class CodegenProperty implements Cloneable, IJsonSchemaValidationProperti
     // the undeclared properties.
     public CodegenProperty items;
     public CodegenProperty additionalProperties;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
     public List<CodegenProperty> requiredVars = new ArrayList<>();
     public CodegenProperty mostInnerItems;
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     public boolean hasValidation; // true if pattern, maximum, etc are set (only used in the mustache template)
     public boolean isInherited;
     public String discriminatorValue;
@@ -619,10 +619,10 @@ public class CodegenProperty implements Cloneable, IJsonSchemaValidationProperti
         try {
             CodegenProperty cp = (CodegenProperty) super.clone();
             if (this._enum != null) {
-                cp._enum = new ArrayList<String>(this._enum);
+                cp._enum = new ArrayList<>(this._enum);
             }
             if (this.allowableValues != null) {
-                cp.allowableValues = new HashMap<String, Object>(this.allowableValues);
+                cp.allowableValues = new HashMap<>(this.allowableValues);
             }
             if (this.items != null) {
                 cp.items = this.items;
@@ -640,7 +640,7 @@ public class CodegenProperty implements Cloneable, IJsonSchemaValidationProperti
                 cp.mostInnerItems = this.mostInnerItems;
             }
             if (this.vendorExtensions != null) {
-                cp.vendorExtensions = new HashMap<String, Object>(this.vendorExtensions);
+                cp.vendorExtensions = new HashMap<>(this.vendorExtensions);
             }
 
             return cp;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java
index 1a99e774e598b70fbaf781ae52c0479d2457c5eb..b3a93f13dcff87413ec48e14158b2f803dc0b8de 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java
@@ -20,7 +20,7 @@ package org.openapitools.codegen;
 import java.util.*;
 
 public class CodegenResponse implements IJsonSchemaValidationProperties {
-    public final List<CodegenProperty> headers = new ArrayList<CodegenProperty>();
+    public final List<CodegenProperty> headers = new ArrayList<>();
     public String code;
     public boolean is1xx;
     public boolean is2xx;
@@ -62,7 +62,7 @@ public class CodegenResponse implements IJsonSchemaValidationProperties {
     public boolean isNull;
     public Object schema;
     public String jsonSchema;
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     private Integer maxProperties;
     private Integer minProperties;
     private boolean uniqueItems;
@@ -78,8 +78,8 @@ public class CodegenResponse implements IJsonSchemaValidationProperties {
     public Number multipleOf;
     public CodegenProperty items;
     public CodegenProperty additionalProperties;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
-    public List<CodegenProperty> requiredVars = new ArrayList<CodegenProperty>();
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
+    public List<CodegenProperty> requiredVars = new ArrayList<>();
     private boolean hasValidation;
     private boolean additionalPropertiesIsAnyType;
     private boolean hasVars;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenSecurity.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenSecurity.java
index a5d5bd4ce85737d20d77c67ac6fd359820a783c1..abd9297ea7e61fcf72a344604f66079df6b20521 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenSecurity.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenSecurity.java
@@ -34,7 +34,7 @@ public class CodegenSecurity {
     // https://datatracker.ietf.org/doc/draft-cavage-http-signatures/
     public Boolean isBasicBasic, isBasicBearer, isHttpSignature;
     public String bearerFormat;
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     // ApiKey specific
     public String keyParamName;
     public Boolean isKeyInQuery, isKeyInHeader, isKeyInCookie;
@@ -69,8 +69,8 @@ public class CodegenSecurity {
         filteredSecurity.refreshUrl = refreshUrl;
         // It is not possible to deep copy the extensions, as we have no idea what types they are.
         // So the filtered method *will* refer to the original extensions, if any.
-        filteredSecurity.vendorExtensions = new HashMap<String, Object>(vendorExtensions);
-        List<Map<String, Object>> returnedScopes = new ArrayList<Map<String, Object>>();
+        filteredSecurity.vendorExtensions = new HashMap<>(vendorExtensions);
+        List<Map<String, Object>> returnedScopes = new ArrayList<>();
         Map<String, Object> lastScope = null;
         for (String filterScopeName : filterScopes) {
             for (Map<String, Object> scope : scopes) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenType.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenType.java
index bf4c9c4d7c3bab0d43dfd6267533fe9edaabf34c..8939a4bbfd3611ff16fcb50aff79bf0787f50931 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenType.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenType.java
@@ -27,7 +27,7 @@ import java.util.Map;
 public enum CodegenType {
     CLIENT, SERVER, DOCUMENTATION, SCHEMA, CONFIG, OTHER;
 
-    private static Map<String, CodegenType> names = new HashMap<String, CodegenType>();
+    private static Map<String, CodegenType> names = new HashMap<>();
 
     @JsonCreator
     public static CodegenType forValue(String value) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 8e76e62e56ccf710dfa26480deff26b4d3ebdbf8..c6ccdea46fb779f557ca00382922e2e5fe80920b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -147,8 +147,8 @@ public class DefaultCodegen implements CodegenConfig {
     protected Map<String, String> typeMapping;
     protected Map<String, String> instantiationTypes;
     protected Set<String> reservedWords;
-    protected Set<String> languageSpecificPrimitives = new HashSet<String>();
-    protected Map<String, String> importMapping = new HashMap<String, String>();
+    protected Set<String> languageSpecificPrimitives = new HashSet<>();
+    protected Map<String, String> importMapping = new HashMap<>();
     protected String modelPackage = "", apiPackage = "", fileSuffix;
     protected String modelNamePrefix = "", modelNameSuffix = "";
     protected String apiNamePrefix = "", apiNameSuffix = "Api";
@@ -159,25 +159,25 @@ public class DefaultCodegen implements CodegenConfig {
     apiTemplateFiles are for API outputs only (controllers/handlers).
     API templates may be written multiple times; APIs are grouped by tag and the file is written once per tag group.
     */
-    protected Map<String, String> apiTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> modelTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> apiTestTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> modelTestTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> apiDocTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> modelDocTemplateFiles = new HashMap<String, String>();
-    protected Map<String, String> reservedWordsMappings = new HashMap<String, String>();
+    protected Map<String, String> apiTemplateFiles = new HashMap<>();
+    protected Map<String, String> modelTemplateFiles = new HashMap<>();
+    protected Map<String, String> apiTestTemplateFiles = new HashMap<>();
+    protected Map<String, String> modelTestTemplateFiles = new HashMap<>();
+    protected Map<String, String> apiDocTemplateFiles = new HashMap<>();
+    protected Map<String, String> modelDocTemplateFiles = new HashMap<>();
+    protected Map<String, String> reservedWordsMappings = new HashMap<>();
     protected String templateDir;
     protected String embeddedTemplateDir;
     protected Map<String, Object> additionalProperties = new HashMap<>();
-    protected Map<String, String> serverVariables = new HashMap<String, String>();
-    protected Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    protected Map<String, String> serverVariables = new HashMap<>();
+    protected Map<String, Object> vendorExtensions = new HashMap<>();
     /*
     Supporting files are those which aren't models, APIs, or docs.
     These get a different map of data bound to the templates. Supporting files are written once.
     See also 'apiTemplateFiles'.
     */
-    protected List<SupportingFile> supportingFiles = new ArrayList<SupportingFile>();
-    protected List<CliOption> cliOptions = new ArrayList<CliOption>();
+    protected List<SupportingFile> supportingFiles = new ArrayList<>();
+    protected List<CliOption> cliOptions = new ArrayList<>();
     protected boolean skipOverwrite;
     protected boolean removeOperationIdPrefix;
     protected String removeOperationIdPrefixDelimiter = "_";
@@ -210,7 +210,7 @@ public class DefaultCodegen implements CodegenConfig {
      */
     protected boolean supportsAdditionalPropertiesWithComposedSchema;
     protected boolean supportsMixins;
-    protected Map<String, String> supportedLibraries = new LinkedHashMap<String, String>();
+    protected Map<String, String> supportedLibraries = new LinkedHashMap<>();
     protected String library;
     protected Boolean sortParamsByRequiredFlag = true;
     protected Boolean sortModelPropertiesByRequiredFlag = false;
@@ -222,7 +222,7 @@ public class DefaultCodegen implements CodegenConfig {
     // How to encode special characters like $
     // They are translated to words like "Dollar" and prefixed with '
     // Then translated back during JSON encoding and decoding
-    protected Map<String, String> specialCharReplacements = new HashMap<String, String>();
+    protected Map<String, String> specialCharReplacements = new HashMap<>();
     // When a model is an alias for a simple type
     protected Map<String, String> typeAliases = null;
     protected Boolean prependFormOrBodyParameters = false;
@@ -236,7 +236,7 @@ public class DefaultCodegen implements CodegenConfig {
     protected boolean useOneOfInterfaces = false;
     // whether or not the oneOf imports machinery should add oneOf interfaces as imports in implementing classes
     protected boolean addOneOfInterfaceImports = false;
-    protected List<CodegenModel> addOneOfInterfaces = new ArrayList<CodegenModel>();
+    protected List<CodegenModel> addOneOfInterfaces = new ArrayList<>();
 
     // flag to indicate whether to only update files whose contents have changed
     protected boolean enableMinimalUpdate = false;
@@ -439,11 +439,11 @@ public class DefaultCodegen implements CodegenConfig {
 
             // Gather data from all the models that contain oneOf into OneOfImplementorAdditionalData classes
             // (see docstring of that class to find out what information is gathered and why)
-            Map<String, OneOfImplementorAdditionalData> additionalDataMap = new HashMap<String, OneOfImplementorAdditionalData>();
+            Map<String, OneOfImplementorAdditionalData> additionalDataMap = new HashMap<>();
             for (Map.Entry<String, Object> modelsEntry : objs.entrySet()) {
                 Map<String, Object> modelsAttrs = (Map<String, Object>) modelsEntry.getValue();
                 List<Object> models = (List<Object>) modelsAttrs.get("models");
-                List<Map<String, String>> modelsImports = (List<Map<String, String>>) modelsAttrs.getOrDefault("imports", new ArrayList<Map<String, String>>());
+                List<Map<String, String>> modelsImports = (List<Map<String, String>>) modelsAttrs.getOrDefault("imports", new ArrayList<>());
                 for (Object _mo : models) {
                     Map<String, Object> mo = (Map<String, Object>) _mo;
                     CodegenModel cm = (CodegenModel) mo.get("model");
@@ -502,7 +502,7 @@ public class DefaultCodegen implements CodegenConfig {
      * @return map of all models indexed by names
      */
     public Map<String, CodegenModel> getAllModels(Map<String, Object> objs) {
-        Map<String, CodegenModel> allModels = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> allModels = new HashMap<>();
         for (Entry<String, Object> entry : objs.entrySet()) {
             String modelName = toModelName(entry.getKey());
             Map<String, Object> inner = (Map<String, Object>) entry.getValue();
@@ -822,9 +822,9 @@ public class DefaultCodegen implements CodegenConfig {
     public void preprocessOpenAPI(OpenAPI openAPI) {
         if (useOneOfInterfaces) {
             // we process the openapi schema here to find oneOf schemas and create interface models for them
-            Map<String, Schema> schemas = new HashMap<String, Schema>(openAPI.getComponents().getSchemas());
+            Map<String, Schema> schemas = new HashMap<>(openAPI.getComponents().getSchemas());
             if (schemas == null) {
-                schemas = new HashMap<String, Schema>();
+                schemas = new HashMap<>();
             }
             Map<String, PathItem> pathItems = openAPI.getPaths();
 
@@ -857,12 +857,12 @@ public class DefaultCodegen implements CodegenConfig {
             }
 
             // also add all properties of all schemas to be checked for oneOf
-            Map<String, Schema> propertySchemas = new HashMap<String, Schema>();
+            Map<String, Schema> propertySchemas = new HashMap<>();
             for (Map.Entry<String, Schema> e : schemas.entrySet()) {
                 Schema s = e.getValue();
                 Map<String, Schema> props = s.getProperties();
                 if (props == null) {
-                    props = new HashMap<String, Schema>();
+                    props = new HashMap<>();
                 }
                 for (Map.Entry<String, Schema> p : props.entrySet()) {
                     propertySchemas.put(e.getKey() + "/" + p.getKey(), p.getValue());
@@ -1546,7 +1546,7 @@ public class DefaultCodegen implements CodegenConfig {
                 .generationMessage(String.format(Locale.ROOT, "OpenAPI Generator: %s (%s)", getName(), codegenType.toValue()))
                 .build();
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "int",
                         "long",
@@ -1563,7 +1563,7 @@ public class DefaultCodegen implements CodegenConfig {
                         "Float")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("array", "List");
         typeMapping.put("set", "Set");
         typeMapping.put("map", "Map");
@@ -1590,9 +1590,9 @@ public class DefaultCodegen implements CodegenConfig {
         typeMapping.put("URI", "URI");
         typeMapping.put("AnyType", "oas_any_type_not_mapped");
 
-        instantiationTypes = new HashMap<String, String>();
+        instantiationTypes = new HashMap<>();
 
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
         cliOptions.add(CliOption.newBoolean(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG,
                 CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG_DESC).defaultValue(Boolean.TRUE.toString()));
@@ -2381,14 +2381,14 @@ public class DefaultCodegen implements CodegenConfig {
         }
     }
 
-    Map<NamedSchema, CodegenProperty> schemaCodegenPropertyCache = new HashMap<NamedSchema, CodegenProperty>();
+    Map<NamedSchema, CodegenProperty> schemaCodegenPropertyCache = new HashMap<>();
 
     protected void updateModelForComposedSchema(CodegenModel m, Schema schema, Map<String, Schema> allDefinitions) {
         final ComposedSchema composed = (ComposedSchema) schema;
-        Map<String, Schema> properties = new LinkedHashMap<String, Schema>();
-        List<String> required = new ArrayList<String>();
-        Map<String, Schema> allProperties = new LinkedHashMap<String, Schema>();
-        List<String> allRequired = new ArrayList<String>();
+        Map<String, Schema> properties = new LinkedHashMap<>();
+        List<String> required = new ArrayList<>();
+        Map<String, Schema> allProperties = new LinkedHashMap<>();
+        List<String> allRequired = new ArrayList<>();
 
         // if schema has properties outside of allOf/oneOf/anyOf also add them to m
         if (composed.getProperties() != null && !composed.getProperties().isEmpty()) {
@@ -2406,7 +2406,7 @@ public class DefaultCodegen implements CodegenConfig {
 
         // TODO revise the logic below to set discriminator, xml attributes
         if (supportsInheritance || supportsMixins) {
-            m.allVars = new ArrayList<CodegenProperty>();
+            m.allVars = new ArrayList<>();
             if (composed.getAllOf() != null) {
                 int modelImplCnt = 0; // only one inline object allowed in a ComposedModel
                 int modelDiscriminators = 0; // only one discriminator allowed in a ComposedModel
@@ -2445,7 +2445,7 @@ public class DefaultCodegen implements CodegenConfig {
         if (!interfaces.isEmpty()) {
             // m.interfaces is for backward compatibility
             if (m.interfaces == null)
-                m.interfaces = new ArrayList<String>();
+                m.interfaces = new ArrayList<>();
 
             for (Schema interfaceSchema : interfaces) {
                 interfaceSchema = unaliasSchema(interfaceSchema, importMapping);
@@ -2532,7 +2532,7 @@ public class DefaultCodegen implements CodegenConfig {
             m.parent = toModelName(parentName);
 
             if (supportsMultipleInheritance) {
-                m.allParents = new ArrayList<String>();
+                m.allParents = new ArrayList<>();
                 for (String pname : allParents) {
                     String pModelName = toModelName(pname);
                     m.allParents.add(pModelName);
@@ -2684,7 +2684,7 @@ public class DefaultCodegen implements CodegenConfig {
             // TODO remove the anyType check here in the future ANyType models can have enums defined
             m.isEnum = true;
             // comment out below as allowableValues is not set in post processing model enum
-            m.allowableValues = new HashMap<String, Object>();
+            m.allowableValues = new HashMap<>();
             m.allowableValues.put("values", schema.getEnum());
         }
         if (!ModelUtils.isArraySchema(schema)) {
@@ -2752,7 +2752,7 @@ public class DefaultCodegen implements CodegenConfig {
         // set isDiscriminator on the discriminator property
         if (m.discriminator != null) {
             String discPropName = m.discriminator.getPropertyBaseName();
-            List<List<CodegenProperty>> listOLists = new ArrayList<List<CodegenProperty>>();
+            List<List<CodegenProperty>> listOLists = new ArrayList<>();
             listOLists.add(m.requiredVars);
             listOLists.add(m.vars);
             listOLists.add(m.allVars);
@@ -3470,13 +3470,13 @@ public class DefaultCodegen implements CodegenConfig {
         //Inline enum case:
         if (p.getEnum() != null && !p.getEnum().isEmpty()) {
             List<Object> _enum = p.getEnum();
-            property._enum = new ArrayList<String>();
+            property._enum = new ArrayList<>();
             for (Object i : _enum) {
                 property._enum.add(String.valueOf(i));
             }
             property.isEnum = true;
 
-            Map<String, Object> allowableValues = new HashMap<String, Object>();
+            Map<String, Object> allowableValues = new HashMap<>();
             allowableValues.put("values", _enum);
             if (allowableValues.size() > 0) {
                 property.allowableValues = allowableValues;
@@ -3489,7 +3489,7 @@ public class DefaultCodegen implements CodegenConfig {
         if (referencedSchema.getEnum() != null && !referencedSchema.getEnum().isEmpty()) {
             List<Object> _enum = referencedSchema.getEnum();
 
-            Map<String, Object> allowableValues = new HashMap<String, Object>();
+            Map<String, Object> allowableValues = new HashMap<>();
             allowableValues.put("values", _enum);
             if (allowableValues.size() > 0) {
                 property.allowableValues = allowableValues;
@@ -3896,7 +3896,7 @@ public class DefaultCodegen implements CodegenConfig {
 
         Map<String, Schema> schemas = ModelUtils.getSchemas(this.openAPI);
         CodegenOperation op = CodegenModelFactory.newInstance(CodegenModelType.OPERATION);
-        Set<String> imports = new HashSet<String>();
+        Set<String> imports = new HashSet<>();
         if (operation.getExtensions() != null && !operation.getExtensions().isEmpty()) {
             op.vendorExtensions.putAll(operation.getExtensions());
 
@@ -3994,15 +3994,15 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         List<Parameter> parameters = operation.getParameters();
-        List<CodegenParameter> allParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> bodyParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> pathParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> queryParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> headerParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> cookieParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> formParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> requiredParams = new ArrayList<CodegenParameter>();
-        List<CodegenParameter> optionalParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> allParams = new ArrayList<>();
+        List<CodegenParameter> bodyParams = new ArrayList<>();
+        List<CodegenParameter> pathParams = new ArrayList<>();
+        List<CodegenParameter> queryParams = new ArrayList<>();
+        List<CodegenParameter> headerParams = new ArrayList<>();
+        List<CodegenParameter> cookieParams = new ArrayList<>();
+        List<CodegenParameter> formParams = new ArrayList<>();
+        List<CodegenParameter> requiredParams = new ArrayList<>();
+        List<CodegenParameter> optionalParams = new ArrayList<>();
 
         CodegenParameter bodyParam = null;
         RequestBody requestBody = operation.getRequestBody();
@@ -4047,7 +4047,7 @@ public class DefaultCodegen implements CodegenConfig {
 
                 // add example
                 if (schemas != null) {
-                    op.requestBodyExamples = new ExampleGenerator(schemas, this.openAPI).generate(null, new ArrayList<String>(getConsumesInfo(this.openAPI, operation)), bodyParam.baseType);
+                    op.requestBodyExamples = new ExampleGenerator(schemas, this.openAPI).generate(null, new ArrayList<>(getConsumesInfo(this.openAPI, operation)), bodyParam.baseType);
                 }
             }
         }
@@ -4760,7 +4760,7 @@ public class DefaultCodegen implements CodegenConfig {
             return Collections.emptyList();
         }
 
-        List<CodegenSecurity> codegenSecurities = new ArrayList<CodegenSecurity>(securitySchemeMap.size());
+        List<CodegenSecurity> codegenSecurities = new ArrayList<>(securitySchemeMap.size());
         for (String key : securitySchemeMap.keySet()) {
             final SecurityScheme securityScheme = securitySchemeMap.get(key);
             if (SecurityScheme.Type.APIKEY.equals(securityScheme.getType())) {
@@ -4860,7 +4860,7 @@ public class DefaultCodegen implements CodegenConfig {
     }
 
     protected void setReservedWordsLowerCase(List<String> words) {
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
         for (String word : words) {
             reservedWords.add(word.toLowerCase(Locale.ROOT));
         }
@@ -4923,9 +4923,9 @@ public class DefaultCodegen implements CodegenConfig {
             return null;
         }
 
-        final List<Map<String, Object>> output = new ArrayList<Map<String, Object>>(examples.size());
+        final List<Map<String, Object>> output = new ArrayList<>(examples.size());
         for (Map.Entry<String, Object> entry : examples.entrySet()) {
-            final Map<String, Object> kv = new HashMap<String, Object>();
+            final Map<String, Object> kv = new HashMap<>();
             kv.put("contentType", entry.getKey());
             kv.put("example", entry.getValue());
             output.add(kv);
@@ -4981,7 +4981,7 @@ public class DefaultCodegen implements CodegenConfig {
             co, Map<String, List<CodegenOperation>> operations) {
         List<CodegenOperation> opList = operations.get(tag);
         if (opList == null) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(tag, opList);
         }
         // check for operationId uniqueness
@@ -5090,7 +5090,7 @@ public class DefaultCodegen implements CodegenConfig {
             m.hasEnums = false; // TODO need to fix as its false in both cases
 
             Set<String> mandatory = required == null ? Collections.<String>emptySet()
-                    : new TreeSet<String>(required);
+                    : new TreeSet<>(required);
 
             // update "vars" without parent's properties (all, required)
             addVars(m, m.vars, properties, mandatory);
@@ -5103,7 +5103,7 @@ public class DefaultCodegen implements CodegenConfig {
 
         if (allProperties != null) {
             Set<String> allMandatory = allRequired == null ? Collections.<String>emptySet()
-                    : new TreeSet<String>(allRequired);
+                    : new TreeSet<>(allRequired);
             // update "vars" with parent's properties (all, required)
             addVars(m, m.allVars, allProperties, allMandatory);
             m.allMandatory = allMandatory;
@@ -5113,14 +5113,14 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         // loop through list to update property name with toVarName
-        Set<String> renamedMandatory = new ConcurrentSkipListSet<String>();
+        Set<String> renamedMandatory = new ConcurrentSkipListSet<>();
         Iterator<String> mandatoryIterator = m.mandatory.iterator();
         while (mandatoryIterator.hasNext()) {
             renamedMandatory.add(toVarName(mandatoryIterator.next()));
         }
         m.mandatory = renamedMandatory;
 
-        Set<String> renamedAllMandatory = new ConcurrentSkipListSet<String>();
+        Set<String> renamedAllMandatory = new ConcurrentSkipListSet<>();
         Iterator<String> allMandatoryIterator = m.allMandatory.iterator();
         while (allMandatoryIterator.hasNext()) {
             renamedAllMandatory.add(toVarName(allMandatoryIterator.next()));
@@ -5573,7 +5573,7 @@ public class DefaultCodegen implements CodegenConfig {
      * @return sanitized string
      */
     public String sanitizeName(String name, String removeCharRegEx) {
-        return sanitizeName(name, removeCharRegEx, new ArrayList<String>());
+        return sanitizeName(name, removeCharRegEx, new ArrayList<>());
     }
 
     /**
@@ -6062,7 +6062,7 @@ public class DefaultCodegen implements CodegenConfig {
             return null;
         }
 
-        Set<String> produces = new ConcurrentSkipListSet<String>();
+        Set<String> produces = new ConcurrentSkipListSet<>();
 
         for (ApiResponse r : operation.getResponses().values()) {
             ApiResponse response = ModelUtils.getReferencedApiResponse(openAPI, r);
@@ -6113,7 +6113,7 @@ public class DefaultCodegen implements CodegenConfig {
         LOGGER.debug("debugging fromRequestBodyToFormParameters= {}", body);
         Schema schema = ModelUtils.getSchemaFromRequestBody(body);
         schema = ModelUtils.getReferencedSchema(this.openAPI, schema);
-        List<String> allRequired = new ArrayList<String>();
+        List<String> allRequired = new ArrayList<>();
         Map<String, Schema> properties = new LinkedHashMap<>();
         // this traverses a composed schema and extracts all properties in each schema into properties
         // TODO in the future have this return one codegenParameter of type object or composed which includes all definition
@@ -6955,7 +6955,7 @@ public class DefaultCodegen implements CodegenConfig {
         cm.name = type;
         cm.classname = type;
         cm.vendorExtensions.put("x-is-one-of-interface", true);
-        cm.interfaceModels = new ArrayList<CodegenModel>();
+        cm.interfaceModels = new ArrayList<>();
 
         addOneOfInterfaces.add(cm);
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java
index 62e678621d46293c6aa26cdc9aadb4ab33425bf8..066f03205256e68309ff5b581073e6ce67d0f3a0 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java
@@ -1247,7 +1247,7 @@ public class DefaultGenerator implements Generator {
      * @return The set of unique imports
      */
     private Set<Map<String,String>> toImportsObjects(Map<String,String> mappedImports){
-        Set<Map<String, String>> result = new TreeSet<Map<String,String>>(
+        Set<Map<String, String>> result = new TreeSet<>(
             (Comparator<Map<String, String>>) (o1, o2) -> {
                 String s1 = o1.get("classname");
                 String s2 = o2.get("classname");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
index cd607fbdb61e0779176fa779b73558246196b828..252e722dcdd26f2371292f285f91fc8c3864814d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
@@ -38,8 +38,8 @@ import java.util.stream.Collectors;
 
 public class InlineModelResolver {
     private OpenAPI openapi;
-    private Map<String, Schema> addedModels = new HashMap<String, Schema>();
-    private Map<String, String> generatedSignature = new HashMap<String, String>();
+    private Map<String, Schema> addedModels = new HashMap<>();
+    private Map<String, String> generatedSignature = new HashMap<>();
 
     // structure mapper sorts properties alphabetically on write to ensure models are
     // serialized consistently for lookup of existing models
@@ -61,7 +61,7 @@ public class InlineModelResolver {
         }
 
         if (openapi.getComponents().getSchemas() == null) {
-            openapi.getComponents().setSchemas(new HashMap<String, Schema>());
+            openapi.getComponents().setSchemas(new HashMap<>());
         }
 
         flattenPaths(openapi);
@@ -154,7 +154,7 @@ public class InlineModelResolver {
 
                     // add to openapi "components"
                     if (openAPI.getComponents().getRequestBodies() == null) {
-                        Map<String, RequestBody> requestBodies = new HashMap<String, RequestBody>();
+                        Map<String, RequestBody> requestBodies = new HashMap<>();
                         requestBodies.put(modelName, rb);
                         openAPI.getComponents().setRequestBodies(requestBodies);
                     } else {
@@ -422,7 +422,7 @@ public class InlineModelResolver {
             return;
         }
 
-        List<String> modelNames = new ArrayList<String>(models.keySet());
+        List<String> modelNames = new ArrayList<>(models.keySet());
         for (String modelName : modelNames) {
             Schema model = models.get(modelName);
             if (ModelUtils.isComposedSchema(model)) {
@@ -561,8 +561,8 @@ public class InlineModelResolver {
         if (properties == null) {
             return;
         }
-        Map<String, Schema> propsToUpdate = new HashMap<String, Schema>();
-        Map<String, Schema> modelsToAdd = new HashMap<String, Schema>();
+        Map<String, Schema> propsToUpdate = new HashMap<>();
+        Map<String, Schema> modelsToAdd = new HashMap<>();
         for (Map.Entry<String, Schema> propertiesEntry : properties.entrySet()) {
             String key = propertiesEntry.getKey();
             Schema property = propertiesEntry.getValue();
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/auth/AuthParser.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/auth/AuthParser.java
index a18d8bdcfdef94354d5a3a49ed09a299f4e57d72..8976daff92b0747b4e7d7313c01193761d4e97e3 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/auth/AuthParser.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/auth/AuthParser.java
@@ -34,7 +34,7 @@ public class AuthParser {
     private static final Logger LOGGER = LoggerFactory.getLogger(AuthParser.class);
 
     public static List<AuthorizationValue> parse(String urlEncodedAuthStr) {
-        List<AuthorizationValue> auths = new ArrayList<AuthorizationValue>();
+        List<AuthorizationValue> auths = new ArrayList<>();
         if (isNotEmpty(urlEncodedAuthStr)) {
             String[] parts = urlEncodedAuthStr.split(",");
             for (String part : parts) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java
index 9d992c1770158aaddf069dc71d6125c77ca684ca..55206896ec8dacb6704eeaab091a7bf728e1b6d3 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java
@@ -148,13 +148,13 @@ public final class CodegenConfiguratorUtils {
 
     private static Set<String> createSetFromCsvList(String csvProperty) {
         final List<String> values = OptionUtils.splitCommaSeparatedList(csvProperty);
-        return new HashSet<String>(values);
+        return new HashSet<>(values);
     }
 
     private static Map<String, String> createMapFromKeyValuePairs(String commaSeparatedKVPairs) {
         final List<Pair<String, String>> pairs = OptionUtils.parseCommaSeparatedTuples(commaSeparatedKVPairs);
 
-        Map<String, String> result = new HashMap<String, String>();
+        Map<String, String> result = new HashMap<>();
 
         for (Pair<String, String> pair : pairs) {
             result.put(pair.getLeft(), pair.getRight());
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
index fc1f7aa77c2c25c0db818b3989e66aa641d31a9d..7650225cf528694c69ae1a408d78f0116421e5d9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
@@ -82,20 +82,20 @@ public class ExampleGenerator {
             ArraySchema as = (ArraySchema) responseSchema;
             if (as.getItems() != null && StringUtils.isEmpty(as.getItems().get$ref())) { // array of primitive types
                 return generate((Map<String, Object>) responseSchema.getExample(),
-                        new ArrayList<String>(producesInfo), as.getItems());
+                        new ArrayList<>(producesInfo), as.getItems());
             } else if (as.getItems() != null && !StringUtils.isEmpty(as.getItems().get$ref())) { // array of model
                 return generate((Map<String, Object>) responseSchema.getExample(),
-                        new ArrayList<String>(producesInfo), ModelUtils.getSimpleRef(as.getItems().get$ref()));
+                        new ArrayList<>(producesInfo), ModelUtils.getSimpleRef(as.getItems().get$ref()));
             } else {
                 // TODO log warning message as such case is not handled at the moment
                 return null;
             }
         } else if (StringUtils.isEmpty(responseSchema.get$ref())) { // primitive type (e.g. integer, string)
             return generate((Map<String, Object>) responseSchema.getExample(),
-                    new ArrayList<String>(producesInfo), responseSchema);
+                    new ArrayList<>(producesInfo), responseSchema);
         } else { // model
             return generate((Map<String, Object>) responseSchema.getExample(),
-                    new ArrayList<String>(producesInfo), ModelUtils.getSimpleRef(responseSchema.get$ref()));
+                    new ArrayList<>(producesInfo), ModelUtils.getSimpleRef(responseSchema.get$ref()));
         }
     }
 
@@ -266,7 +266,7 @@ public class ExampleGenerator {
             }
             return (int) randomNumber(min, max);
         } else if (ModelUtils.isMapSchema(property)) {
-            Map<String, Object> mp = new HashMap<String, Object>();
+            Map<String, Object> mp = new HashMap<>();
             if (property.getName() != null) {
                 mp.put(property.getName(),
                         resolvePropertyToExample(propertyName, mediaType, ModelUtils.getAdditionalProperties(openAPI, property), processedModels));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/XmlExampleGenerator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/XmlExampleGenerator.java
index 91d5a0120a483237b3005a3db07a4c29af28509d..a3a233ad4c27407cfdf0228b1eab7e0b4b86192d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/XmlExampleGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/XmlExampleGenerator.java
@@ -39,7 +39,7 @@ public class XmlExampleGenerator {
     public XmlExampleGenerator(Map<String, Schema> examples) {
         this.examples = examples;
         if (examples == null) {
-            this.examples = new HashMap<String, Schema>();
+            this.examples = new HashMap<>();
         }
     }
 
@@ -63,13 +63,13 @@ public class XmlExampleGenerator {
         if (path.contains(modelName)) {
             return EMPTY;
         }
-        final Set<String> selfPath = new HashSet<String>(path);
+        final Set<String> selfPath = new HashSet<>(path);
         selfPath.add(modelName);
 
         StringBuilder sb = new StringBuilder();
         // attributes
-        Map<String, Schema> attributes = new LinkedHashMap<String, Schema>();
-        Map<String, Schema> elements = new LinkedHashMap<String, Schema>();
+        Map<String, Schema> attributes = new LinkedHashMap<>();
+        Map<String, Schema> elements = new LinkedHashMap<>();
 
         String name = modelName;
         XML xml = schema.getXml();
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java
index 7ef64adcd71550be98b3d3e4b192f9c226ff13fb..aa274511d8a9215b0303e49027702baea91c89c1 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java
@@ -155,7 +155,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
                         "xor")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "Swagger.Date");
         typeMapping.put("DateTime", "Swagger.Datetime");
         typeMapping.put("string", "Swagger.UString");
@@ -172,7 +172,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         typeMapping.put("binary", "Swagger.Binary");
 
         // Mapping to convert an Ada required type to an optional type (nullable).
-        nullableTypeMapping = new HashMap<String, String>();
+        nullableTypeMapping = new HashMap<>();
         nullableTypeMapping.put("Swagger.Date", "Swagger.Nullable_Date");
         nullableTypeMapping.put("Swagger.Datetime", "Swagger.Nullable_Date");
         nullableTypeMapping.put("Swagger.UString", "Swagger.Nullable_UString");
@@ -181,10 +181,10 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         nullableTypeMapping.put("Boolean", "Swagger.Nullable_Boolean");
         nullableTypeMapping.put("Swagger.Object", "Swagger.Object");
 
-        modelDepends = new HashMap<String, List<String>>();
-        orderedModels = new ArrayList<Map<String, Object>>();
-        operationsScopes = new HashMap<String, String>();
-        super.importMapping = new HashMap<String, String>();
+        modelDepends = new HashMap<>();
+        orderedModels = new ArrayList<>();
+        operationsScopes = new HashMap<>();
+        super.importMapping = new HashMap<>();
 
         // CLI options
         addOption(CodegenConstants.PROJECT_NAME, "GNAT project name",
@@ -193,7 +193,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         modelNameSuffix = "Type";
         embeddedTemplateDir = templateDir = "Ada";
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("integer", "boolean", "number", "long", "float",
                         "double", "object", "string", "date", "DateTime", "binary"));
     }
@@ -651,7 +651,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
             Object v = model.get("model");
             if (v instanceof CodegenModel) {
                 CodegenModel m = (CodegenModel) v;
-                List<String> d = new ArrayList<String>();
+                List<String> d = new ArrayList<>();
                 for (CodegenProperty p : m.vars) {
                     boolean isModel = false;
                     CodegenProperty item = p;
@@ -687,8 +687,8 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         //     if I find a model that has no dependencies, or all of its dependencies are in revisedOrderedModels, consider it the independentModel
         //   put the independentModel at the end of revisedOrderedModels, and remove it from orderedModels
         //
-        List<Map<String, Object>> revisedOrderedModels = new ArrayList<Map<String, Object>>();
-        List<String> collectedModelNames = new ArrayList<String>();
+        List<Map<String, Object>> revisedOrderedModels = new ArrayList<>();
+        List<String> collectedModelNames = new ArrayList<>();
         int sizeOrderedModels = orderedModels.size();
         for (int i = 0; i < sizeOrderedModels; i++) {
             Map<String, Object> independentModel = null;
@@ -760,7 +760,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
      * @return the authMethods to be used by the operation with its required scopes.
      */
     private List<CodegenSecurity> postProcessAuthMethod(List<CodegenSecurity> authMethods, Map<String, List<String>> scopes) {
-        List<CodegenSecurity> result = (scopes == null) ? null : new ArrayList<CodegenSecurity>();
+        List<CodegenSecurity> result = (scopes == null) ? null : new ArrayList<>();
         if (authMethods != null) {
             for (CodegenSecurity authMethod : authMethods) {
                 if (authMethod.scopes != null) {
@@ -803,7 +803,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
                     opSecurity.isKeyInQuery = authMethod.isKeyInQuery;
                     opSecurity.flow = authMethod.flow;
                     opSecurity.tokenUrl = authMethod.tokenUrl;
-                    List<Map<String, Object>> opAuthScopes = new ArrayList<Map<String, Object>>();
+                    List<Map<String, Object>> opAuthScopes = new ArrayList<>();
                     for (String opScopeName : opScopes) {
                         for (Map<String, Object> scope : authMethod.scopes) {
                             String name = (String) scope.get("scope");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java
index 278be7eada5d3128fcae1d261cee8543beb182df..56ee0cc7e977a2b6b90c1558fda8c58b2fe3239d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java
@@ -439,7 +439,7 @@ public abstract class AbstractApexCodegen extends DefaultCodegen implements Code
 
         // TODO Check enum model handling
         if (cm.interfaces == null) {
-            cm.interfaces = new ArrayList<String>();
+            cm.interfaces = new ArrayList<>();
         }
 
         Boolean hasDefaultValues = false;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
index 086d63af29b6a5180aee6c82461717abbaf3038f..d920c629b4cba3205c12c98d75b28e75682383ec 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
@@ -81,9 +81,9 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
     protected boolean supportNullable = Boolean.FALSE;
 
     // nullable type
-    protected Set<String> nullableType = new HashSet<String>();
+    protected Set<String> nullableType = new HashSet<>();
 
-    protected Set<String> valueTypes = new HashSet<String>();
+    protected Set<String> valueTypes = new HashSet<>();
 
     private final Logger LOGGER = LoggerFactory.getLogger(AbstractCSharpCodegen.class);
 
@@ -104,14 +104,14 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         outputFolder = "generated-code" + File.separator + this.getName();
         embeddedTemplateDir = templateDir = this.getName();
 
-        collectionTypes = new HashSet<String>(
+        collectionTypes = new HashSet<>(
                 Arrays.asList(
                         "IList", "List",
                         "ICollection", "Collection",
                         "IEnumerable")
         );
 
-        mapTypes = new HashSet<String>(
+        mapTypes = new HashSet<>(
                 Arrays.asList("IDictionary")
         );
 
@@ -141,7 +141,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         );
 
         // TODO: Either include fully qualified names here or handle in DefaultCodegen via lastIndexOf(".") search
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "string",
@@ -184,7 +184,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
 
 
         // Nullable types here assume C# 2 support is not part of base
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "string");
         typeMapping.put("binary", "byte[]");
         typeMapping.put("ByteArray", "byte[]");
@@ -207,11 +207,11 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         typeMapping.put("AnyType", "Object");
 
         // nullable type
-        nullableType = new HashSet<String>(
+        nullableType = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double", "DateTime", "DateTimeOffset", "Guid")
         );
         // value Types
-        valueTypes = new HashSet<String>(
+        valueTypes = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double")
         );
     }
@@ -465,7 +465,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
      */
     @SuppressWarnings({"unchecked"})
     private void postProcessEnumRefs(final Map<String, Object> models) {
-        Map<String, CodegenModel> enumRefs = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> enumRefs = new HashMap<>();
         for (Map.Entry<String, Object> entry : models.entrySet()) {
             CodegenModel model = ModelUtils.getModelByName(entry.getKey(), models);
             if (model.isEnum) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
index a6950c776fe7d3fe57acb09e92f37da29f58a977..694cea8e452f9d72d81f5f8a55c4c651492d60bd 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
@@ -344,7 +344,7 @@ abstract public class AbstractCppCodegen extends DefaultCodegen implements Codeg
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
         List<Server> serverList = openAPI.getServers();
-        List<CodegenServer> CodegenServerList = new ArrayList<CodegenServer>();
+        List<CodegenServer> CodegenServerList = new ArrayList<>();
         URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         String port = URLPathUtils.getPort(url, "");
         String host = url.getHost();
@@ -364,7 +364,7 @@ abstract public class AbstractCppCodegen extends DefaultCodegen implements Codeg
                 CodegenServer s = new CodegenServer();
                 s.description = server.getDescription();
                 s.url = server.getUrl();
-                s.variables = new ArrayList<CodegenServerVariable>();
+                s.variables = new ArrayList<>();
                 ServerVariables serverVars = server.getVariables();
                 if(serverVars != null){
                 serverVars.forEach((key,value) -> {
@@ -409,7 +409,7 @@ abstract public class AbstractCppCodegen extends DefaultCodegen implements Codeg
     }
 
     private void addForwardDeclarations(CodegenModel parentModel, Map<String, Object> objs) {
-        List<String> forwardDeclarations = new ArrayList<String>();
+        List<String> forwardDeclarations = new ArrayList<>();
         if(!parentModel.hasVars) {
             return;
         }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractEiffelCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractEiffelCodegen.java
index e11579a271312536688c649280e7128532df4fcf..9bc4113358b1da22881be150d25b8074016bda0b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractEiffelCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractEiffelCodegen.java
@@ -53,9 +53,9 @@ public abstract class AbstractEiffelCodegen extends DefaultCodegen implements Co
                 "redefine", "rename", "require", "rescue", "Result", "retry", "select", "separate", "then", "True",
                 "TUPLE", "undefine", "until", "variant", "Void", "when", "xor"));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList("map", "array"));
+        defaultIncludes = new HashSet<>(Arrays.asList("map", "array"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("BOOLEAN", "INTEGER_8", "INTEGER_16", "INTEGER_32", "INTEGER_64", "NATURAL_8",
                         "NATURAL_16", "NATURAL_32", "NATURAL_64", "REAL_32", "REAL_64"));
 
@@ -559,7 +559,7 @@ public abstract class AbstractEiffelCodegen extends DefaultCodegen implements Co
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java
index 527481ecbdb1799e1a0576e112d57e94fe20c893..f2335473054914e094e42802a26b62e55e832748 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java
@@ -73,7 +73,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
     // true if nullable types will be supported (as option)
     protected boolean supportNullable = Boolean.TRUE;
 
-    protected Set<String> nullableType = new HashSet<String>();
+    protected Set<String> nullableType = new HashSet<>();
 
 
     private final Logger LOGGER = LoggerFactory.getLogger(AbstractFSharpCodegen.class);
@@ -89,9 +89,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         outputFolder = this.getName();
         embeddedTemplateDir = templateDir = this.getName();
 
-        collectionTypes = new HashSet<String>(Arrays.asList("list", "seq"));
+        collectionTypes = new HashSet<>(Arrays.asList("list", "seq"));
 
-        mapTypes = new HashSet<String>(
+        mapTypes = new HashSet<>(
                 Arrays.asList("IDictionary")
         );
 
@@ -114,7 +114,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         );
 
         // TODO - these are based on C# generator, do we need to add any more?
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "string",
@@ -156,7 +156,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         instantiationTypes.put("map", "IDictionary");
 
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "string");
         typeMapping.put("binary", "byte[]");
         typeMapping.put("ByteArray", "byte[]");
@@ -177,7 +177,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         typeMapping.put("URI", "string");
 
         // nullable type
-        nullableType = new HashSet<String>(
+        nullableType = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double", "string", "Guid", "apiKey")
         );
     }
@@ -352,9 +352,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
     @SuppressWarnings({"unchecked"})
     public Map<String, Object> postProcessDependencyOrders(final Map<String, Object> objs) {
 
-        Map<String, Set<String>> dependencies = new HashMap<String, Set<String>>();
+        Map<String, Set<String>> dependencies = new HashMap<>();
 
-        List<String> classNames = new ArrayList<String>();
+        List<String> classNames = new ArrayList<>();
 
         for (String k : objs.keySet()) {
             CodegenModel model = ModelUtils.getModelByName(k, objs);
@@ -381,7 +381,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
             }
         }
 
-        Map<String, Object> sorted = new LinkedHashMap<String, Object>();
+        Map<String, Object> sorted = new LinkedHashMap<>();
         for (int i = sortedKeys.length - 1; i >= 0; i--) {
             Object k = sortedKeys[i];
             sorted.put(k.toString(), objs.get(k));
@@ -402,7 +402,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
      */
     @SuppressWarnings({"unchecked"})
     private void postProcessEnumRefs(final Map<String, Object> models) {
-        Map<String, CodegenModel> enumRefs = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> enumRefs = new HashMap<>();
         for (Map.Entry<String, Object> entry : models.entrySet()) {
             CodegenModel model = ModelUtils.getModelByName(entry.getKey(), models);
             if (model.isEnum) {
@@ -455,9 +455,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
                     // Since we iterate enumVars for modelInnerEnum and enumClass templates, and CodegenModel is missing some of CodegenProperty's properties,
                     // we can take advantage of Mustache's contextual lookup to add the same "properties" to the model's enumVars scope rather than CodegenProperty's scope.
                     List<Map<String, String>> enumVars = (ArrayList<Map<String, String>>) model.allowableValues.get("enumVars");
-                    List<Map<String, Object>> newEnumVars = new ArrayList<Map<String, Object>>();
+                    List<Map<String, Object>> newEnumVars = new ArrayList<>();
                     for (Map<String, String> enumVar : enumVars) {
-                        Map<String, Object> mixedVars = new HashMap<String, Object>();
+                        Map<String, Object> mixedVars = new HashMap<>();
                         mixedVars.putAll(enumVar);
 
                         mixedVars.put("isString", isString);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java
index 3c3f002b18760c2df0aba452c6e974a95ab423e2..54c65b90b2a1186aa68f6d6bd984c0c968469fb3 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java
@@ -56,7 +56,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         supportsInheritance = true;
         hideGenerationTimestamp = Boolean.FALSE;
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
@@ -77,7 +77,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
                 // Added "error" as it's used so frequently that it may as well be a keyword
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "string",
                         "bool",
@@ -133,14 +133,14 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         typeMapping.put("object", "map[string]interface{}");
         typeMapping.put("AnyType", "interface{}");
 
-        numberTypes = new HashSet<String>(
+        numberTypes = new HashSet<>(
                 Arrays.asList(
                         "uint", "uint8", "uint16", "uint32", "uint64",
                         "int", "int8", "int16", "int32", "int64",
                         "float32", "float64")
         );
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
         cliOptions.clear();
         cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Go package name (convention: lowercase).")
@@ -252,7 +252,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         String[] parts = name.split("_");
         String suffix = parts[parts.length - 1];
 
-        Set<String> reservedSuffixes = new HashSet<String>(Arrays.asList(
+        Set<String> reservedSuffixes = new HashSet<>(Arrays.asList(
                 // Test
                 "test",
                 // $GOOS
@@ -699,7 +699,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
@@ -813,7 +813,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         }
 
         // only process the following type (or we can simply rely on the file extension to check if it's a Go file)
-        Set<String> supportedFileType = new HashSet<String>(
+        Set<String> supportedFileType = new HashSet<>(
                 Arrays.asList(
                         "supporting-mustache",
                         "model-test",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGraphQLCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGraphQLCodegen.java
index 0742a6b445904d67fe9b5f40b63eab062860b08f..bc9914a2b00f967d732a945c2d50d26d7d90d5a1 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGraphQLCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGraphQLCodegen.java
@@ -55,13 +55,13 @@ public abstract class AbstractGraphQLCodegen extends DefaultCodegen implements C
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "null",
                         "ID",
@@ -344,7 +344,7 @@ public abstract class AbstractGraphQLCodegen extends DefaultCodegen implements C
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index 77cd594f7fb8e4d199974112f11ff665be7fef0a..f518e875a08f99270984198f6e6ea9c6e21b4792 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -164,7 +164,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
                         "native", "super", "while", "null")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "boolean",
@@ -1260,7 +1260,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
             // if the import package happens to be found in the importMapping (key)
             // add the corresponding import package to the list
             if (importMapping.containsKey(_import)) {
-                Map<String, String> newImportMap = new HashMap<String, String>();
+                Map<String, String> newImportMap = new HashMap<>();
                 newImportMap.put("import", importMapping.get(_import));
                 listIterator.add(newImportMap);
             }
@@ -1285,7 +1285,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
         for (CodegenOperation op : operationList) {
-            Collection<String> operationImports = new ConcurrentSkipListSet<String>();
+            Collection<String> operationImports = new ConcurrentSkipListSet<>();
             for (CodegenParameter p : op.allParams) {
                 if (importMapping.containsKey(p.dataType)) {
                     operationImports.add(importMapping.get(p.dataType));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java
index d930e0b33e680307cdaeb254176a2b03ac13df67..c3f41d9a78f420597f8819ffae190dbac59cc91d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java
@@ -148,9 +148,9 @@ public abstract class AbstractJavaJAXRSServerCodegen extends AbstractJavaCodegen
                 if (path.readOperations() != null) {
                     for (Operation operation : path.readOperations()) {
                         if (operation.getTags() != null) {
-                            List<Map<String, String>> tags = new ArrayList<Map<String, String>>();
+                            List<Map<String, String>> tags = new ArrayList<>();
                             for (String tag : operation.getTags()) {
-                                Map<String, String> value = new HashMap<String, String>();
+                                Map<String, String> value = new HashMap<>();
                                 value.put("tag", tag);
                                 tags.add(value);
                             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java
index da93330eca2e57dab8f9128e1ad36a090b527d8f..71f0962ed03b69d8568880e661cdd37d01838147 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java
@@ -78,7 +78,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         supportsInheritance = true;
         setSortModelPropertiesByRequiredFlag(true);
 
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
                 "kotlin.Byte",
                 "kotlin.ByteArray",
                 "kotlin.Short",
@@ -97,7 +97,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
 
         // this includes hard reserved words defined by https://github.com/JetBrains/kotlin/blob/master/core/descriptors/src/org/jetbrains/kotlin/renderer/KeywordStringsGenerated.java
         // as well as keywords from https://kotlinlang.org/docs/reference/keyword-reference.html
-        reservedWords = new HashSet<String>(Arrays.asList(
+        reservedWords = new HashSet<>(Arrays.asList(
                 "abstract",
                 "actual",
                 "annotation",
@@ -171,7 +171,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
                 "while"
         ));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        defaultIncludes = new HashSet<>(Arrays.asList(
                 "kotlin.Byte",
                 "kotlin.ByteArray",
                 "kotlin.Short",
@@ -187,7 +187,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
                 "kotlin.collections.Map"
         ));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "kotlin.String");
         typeMapping.put("boolean", "kotlin.Boolean");
         typeMapping.put("integer", "kotlin.Int");
@@ -214,7 +214,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         instantiationTypes.put("list", "kotlin.collections.ArrayList");
         instantiationTypes.put("map", "kotlin.collections.HashMap");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("BigDecimal", "java.math.BigDecimal");
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java
index db208bb9829df691093e9a4ac4d2d9d6c784f0c8..8c2b79f93704caa5cd910680942ae52b72186f7f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java
@@ -79,7 +79,7 @@ public abstract class AbstractPhpCodegen extends DefaultCodegen implements Codeg
         );
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "boolean",
@@ -107,7 +107,7 @@ public abstract class AbstractPhpCodegen extends DefaultCodegen implements Codeg
         additionalProperties.put("primitives", primitives);
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("number", "float");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonConnexionServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonConnexionServerCodegen.java
index 38cbac0eecf979ee88ec535c5a37f5339d268956..afd233784aae34398945533db2908cd4cf92dbc8 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonConnexionServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonConnexionServerCodegen.java
@@ -108,7 +108,7 @@ public abstract class AbstractPythonConnexionServerCodegen extends AbstractPytho
         supportingFiles.add(new SupportingFile("test-requirements.mustache", "", "test-requirements.txt"));
         supportingFiles.add(new SupportingFile("requirements.mustache", "", "requirements.txt"));
 
-        regexModifiers = new HashMap<Character, String>();
+        regexModifiers = new HashMap<>();
         regexModifiers.put('i', "IGNORECASE");
         regexModifiers.put('l', "LOCALE");
         regexModifiers.put('m', "MULTILINE");
@@ -455,7 +455,7 @@ public abstract class AbstractPythonConnexionServerCodegen extends AbstractPytho
 
     @SuppressWarnings("unchecked")
     private static List<Map<String, Object>> getOperations(Map<String, Object> objs) {
-        List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
+        List<Map<String, Object>> result = new ArrayList<>();
         Map<String, Object> apiInfo = (Map<String, Object>) objs.get("apiInfo");
         List<Map<String, Object>> apis = (List<Map<String, Object>>) apiInfo.get("apis");
         for (Map<String, Object> api : apis) {
@@ -471,9 +471,9 @@ public abstract class AbstractPythonConnexionServerCodegen extends AbstractPytho
             opsByPath.put(op.path, op);
         }
 
-        List<Map<String, Object>> opsByPathList = new ArrayList<Map<String, Object>>();
+        List<Map<String, Object>> opsByPathList = new ArrayList<>();
         for (Map.Entry<String, Collection<CodegenOperation>> entry : opsByPath.asMap().entrySet()) {
-            Map<String, Object> opsByPathEntry = new HashMap<String, Object>();
+            Map<String, Object> opsByPathEntry = new HashMap<>();
             opsByPathList.add(opsByPathEntry);
             opsByPathEntry.put("path", entry.getKey());
             opsByPathEntry.put("operation", entry.getValue());
@@ -709,7 +709,7 @@ public abstract class AbstractPythonConnexionServerCodegen extends AbstractPytho
             }
 
             String regex = pattern.substring(1, i).replace("'", "\\'");
-            List<String> modifiers = new ArrayList<String>();
+            List<String> modifiers = new ArrayList<>();
 
             for (char c : pattern.substring(i).toCharArray()) {
                 if (regexModifiers.containsKey(c)) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java
index 65ec72caca64bf791abbcbdb3375a1eca38540ab..cb5b09e5435e1af43be3cdc30d35a6e4825f05fd 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java
@@ -123,7 +123,7 @@ public abstract class AbstractScalaCodegen extends DefaultCodegen {
         typeMapping.put("ByteArray", "Array[Byte]");
 
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("ListBuffer", "scala.collection.mutable.ListBuffer");
         // although Seq is a predef, before Scala 2.13, it _could_ refer to a mutable Seq in some cases.
         importMapping.put("Seq", "scala.collection.immutable.Seq");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java
index 1059732e84e7a75c7118e8e12107b0a5e8950696..b3df16f6b2c140b32502fbe4fd9ab40b6ebc849b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java
@@ -143,7 +143,7 @@ public abstract class AbstractTypeScriptClientCodegen extends DefaultCodegen imp
 
         instantiationTypes.put("array", "Array");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("Set", "Set");
         typeMapping.put("set", "Set");
         typeMapping.put("Array", "Array");
@@ -387,7 +387,7 @@ public abstract class AbstractTypeScriptClientCodegen extends DefaultCodegen imp
     }
 
     protected String toTypescriptTypeName(final String name, String safePrefix) {
-        ArrayList<String> exceptions = new ArrayList<String>(Arrays.asList("\\|", " "));
+        ArrayList<String> exceptions = new ArrayList<>(Arrays.asList("\\|", " "));
         String sanName = sanitizeName(name, "(?![| ])\\W", exceptions);
 
         sanName = camelize(sanName);
@@ -460,12 +460,12 @@ public abstract class AbstractTypeScriptClientCodegen extends DefaultCodegen imp
         } else if (ModelUtils.isIntegerSchema(p)) {
             // Handle integer enums
             if (p.getEnum() != null) {
-                return numericEnumValuesToEnumTypeUnion(new ArrayList<Number>(p.getEnum()));
+                return numericEnumValuesToEnumTypeUnion(new ArrayList<>(p.getEnum()));
             }
         } else if (ModelUtils.isNumberSchema(p)) {
             // Handle double enums
             if (p.getEnum() != null) {
-                return numericEnumValuesToEnumTypeUnion(new ArrayList<Number>(p.getEnum()));
+                return numericEnumValuesToEnumTypeUnion(new ArrayList<>(p.getEnum()));
             }
         }
         /* TODO revise the logic below
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AndroidClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AndroidClientCodegen.java
index d1c6fb6a3e8491cb8eb505df36231f76a29e939c..b0bbe14c92ec1a2a3b9194bb9169f9467306b5a4 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AndroidClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AndroidClientCodegen.java
@@ -117,7 +117,7 @@ public class AndroidClientCodegen extends DefaultCodegen implements CodegenConfi
                         "native", "super", "while", "null")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "boolean",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Apache2ConfigCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Apache2ConfigCodegen.java
index 50efc04b72e4388a6b7918e9fa5ec36fdd37fd4c..4328faeb898717b45e3513a561075b39e31de114 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Apache2ConfigCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Apache2ConfigCodegen.java
@@ -92,13 +92,13 @@ public class Apache2ConfigCodegen extends DefaultCodegen implements CodegenConfi
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
-        List<CodegenOperation> newOpList = new ArrayList<CodegenOperation>();
+        List<CodegenOperation> newOpList = new ArrayList<>();
 
         for (CodegenOperation op : operationList) {
             String path = op.path;
 
             String[] items = path.split("/", -1);
-            List<String> splitPath = new ArrayList<String>();
+            List<String> splitPath = new ArrayList<>();
             for (String item : items) {
                 if (item.matches("^\\{(.*)\\}$")) {
                     item = "*";
@@ -114,7 +114,7 @@ public class Apache2ConfigCodegen extends DefaultCodegen implements CodegenConfi
                         foundInNewList = true;
                         List<CodegenOperation> currentOtherMethodList = (List<CodegenOperation>) op1.vendorExtensions.get("x-codegen-otherMethods");
                         if (currentOtherMethodList == null) {
-                            currentOtherMethodList = new ArrayList<CodegenOperation>();
+                            currentOtherMethodList = new ArrayList<>();
                         }
                         op.operationIdCamelCase = op1.operationIdCamelCase;
                         currentOtherMethodList.add(op);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ApexClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ApexClientCodegen.java
index e5ad82eb1b01540cf5b3d0f4f1e7a87ca6d3b4fa..936574046e8bc7677847e36eec0f17dc1cfb17a5 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ApexClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ApexClientCodegen.java
@@ -49,7 +49,7 @@ public class ApexClientCodegen extends AbstractApexCodegen {
     private String namedCredential;
     private String srcPath = "force-app/main/default/";
     private String sfdxConfigPath = "config/";
-    private HashMap<String, Object> primitiveDefaults = new HashMap<String, Object>();
+    private HashMap<String, Object> primitiveDefaults = new HashMap<>();
 
     public ApexClientCodegen() {
         super();
@@ -113,7 +113,7 @@ public class ApexClientCodegen extends AbstractApexCodegen {
                         "virtual", "void", "webservice", "when", "where", "while"
                 ));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("Blob", "Boolean", "Date", "Datetime", "Decimal", "Double", "ID",
                         "Integer", "Long", "Object", "String", "Time"
                 ));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AsciidocDocumentationCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AsciidocDocumentationCodegen.java
index fa66f2a33a2f947b7b153898dac8cef60d8da35c..cb14de0a7b971f5510035f991b37461332e9464b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AsciidocDocumentationCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AsciidocDocumentationCodegen.java
@@ -217,7 +217,7 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
         outputFolder = "generated-code" + File.separator + "asciidoc";
         embeddedTemplateDir = templateDir = "asciidoc-documentation";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -264,10 +264,10 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.adoc"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
-        importMapping = new HashMap<String, String>();
+        languageSpecificPrimitives = new HashSet<>();
+        importMapping = new HashMap<>();
 
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/BashClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/BashClientCodegen.java
index 85e68a2035494be00a796f3367927e0e3e32f8e5..5ca5fbb156beff80ec27e40d37d12810de59b5ad 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/BashClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/BashClientCodegen.java
@@ -209,7 +209,7 @@ public class BashClientCodegen extends DefaultCodegen implements CodegenConfig {
         /**
          * Bash reserved words.
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "case",
                         "do",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java
index 58803d150a15c39904ba8e6f11fb567100e7b33b..60ed48b5a0144ee8efe133d9315593d930a601cc 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java
@@ -874,7 +874,7 @@ public class CLibcurlClientCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // only process the following type (or we can simply rely on the file extension to check if it's a .c or .h file)
-        Set<String> supportedFileType = new HashSet<String>(
+        Set<String> supportedFileType = new HashSet<>(
                 Arrays.asList(
                         "supporting-mustache",
                         "model-test",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
index 3b06619b8459b3cd0817954d366061373c0b8894..b3c3f0832d1d9f22bb2c4d1f4374bcf74a742ed6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
@@ -243,7 +243,7 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
                 CodegenConstants.CASE_INSENSITIVE_RESPONSE_HEADERS_DESC,
                 this.caseInsensitiveResponseHeaders);
 
-        regexModifiers = new HashMap<Character, String>();
+        regexModifiers = new HashMap<>();
         regexModifiers.put('i', "IgnoreCase");
         regexModifiers.put('m', "Multiline");
         regexModifiers.put('s', "Singleline");
@@ -662,7 +662,7 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
             }
 
             String regex = pattern.substring(1, i).replace("'", "\'");
-            List<String> modifiers = new ArrayList<String>();
+            List<String> modifiers = new ArrayList<>();
 
             // perl requires an explicit modifier to be culture specific and .NET is the reverse.
             modifiers.add("CultureInvariant");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
index ab5cd5bb3d0e0ea209cadc8b20702ca1ae6472ed..1aa568ff7c257bf63aeecd864492fb4e8fc7a64a 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
@@ -133,7 +133,7 @@ public class CSharpNetCoreClientCodegen extends AbstractCSharpCodegen {
         );
 
         // mapped non-nullable type without ?
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "string");
         typeMapping.put("binary", "byte[]");
         typeMapping.put("ByteArray", "byte[]");
@@ -493,7 +493,7 @@ public class CSharpNetCoreClientCodegen extends AbstractCSharpCodegen {
             }
 
             String regex = pattern.substring(1, i).replace("'", "\'").replace("\"", "\"\"");
-            List<String> modifiers = new ArrayList<String>();
+            List<String> modifiers = new ArrayList<>();
 
             // perl requires an explicit modifier to be culture specific and .NET is the reverse.
             modifiers.add("CultureInvariant");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ConfluenceWikiCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ConfluenceWikiCodegen.java
index 1ed37650f7f9f88b376f7a756fabd56f4c3397f4..edb5f81cd0d3146d496e910c5abfcbf56a037520 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ConfluenceWikiCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ConfluenceWikiCodegen.java
@@ -55,7 +55,7 @@ public class ConfluenceWikiCodegen extends DefaultCodegen implements CodegenConf
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "confluenceWikiDocs";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -80,10 +80,10 @@ public class ConfluenceWikiCodegen extends DefaultCodegen implements CodegenConf
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "confluence-markup.txt"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
-        importMapping = new HashMap<String, String>();
+        languageSpecificPrimitives = new HashSet<>();
+        importMapping = new HashMap<>();
     }
 
     @Override
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
index 0aa6cb2568546dfe2743fc95d2011cebaefb3dd2..460def58afc368e4a8489a5229c46441a0d740f2 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
@@ -116,10 +116,10 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "std::string");
         typeMapping.put("DateTime", "std::string");
         typeMapping.put("string", "std::string");
@@ -137,7 +137,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "std::string");
         typeMapping.put("ByteArray", "std::string");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQtAbstractCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQtAbstractCodegen.java
index 859ab9d69cd0c9f652db412bd27dac956f59b49d..cef3b4039615787ec8cc7123fd1d6285c98c15e6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQtAbstractCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQtAbstractCodegen.java
@@ -22,13 +22,13 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
     protected static final String CPP_NAMESPACE_DESC = "C++ namespace (convention: name::space::for::api).";
     protected static final String CONTENT_COMPRESSION_ENABLED = "contentCompression";
     protected static final String CONTENT_COMPRESSION_ENABLED_DESC = "Enable Compressed Content Encoding for requests and responses";
-    protected Set<String> foundationClasses = new HashSet<String>();
+    protected Set<String> foundationClasses = new HashSet<>();
     protected String cppNamespace = "OpenAPI";
-    protected Map<String, String> namespaces = new HashMap<String, String>();
-    protected Set<String> systemIncludes = new HashSet<String>();
+    protected Map<String, String> namespaces = new HashMap<>();
+    protected Set<String> systemIncludes = new HashSet<>();
     protected boolean isContentCompressionEnabled = false;
 
-    protected Set<String> nonFrameworkPrimitives = new HashSet<String>();
+    protected Set<String> nonFrameworkPrimitives = new HashSet<>();
 
     public CppQtAbstractCodegen() {
         super();
@@ -75,7 +75,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "qint32",
@@ -93,7 +93,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
                         "QByteArray")
         );
         languageSpecificPrimitives.addAll(foundationClasses);
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         typeMapping.put("date", "QDate");
         typeMapping.put("DateTime", "QDateTime");
@@ -116,8 +116,8 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
         typeMapping.put("URI", "QString");
         typeMapping.put("file", "QByteArray");
         typeMapping.put("binary", "QByteArray");
-        importMapping = new HashMap<String, String>();
-        namespaces = new HashMap<String, String>();
+        importMapping = new HashMap<>();
+        namespaces = new HashMap<>();
 
         systemIncludes.add("QString");
         systemIncludes.add("QList");
@@ -315,7 +315,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
         List<CodegenOperation> operations = (List<CodegenOperation>) objectMap.get("operation");
 
         List<Map<String, String>> imports = (List<Map<String, String>>) objs.get("imports");
-        Map<String, CodegenModel> codegenModels = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> codegenModels = new HashMap<>();
 
         for (Object moObj : allModels) {
             CodegenModel mo = ((Map<String, CodegenModel>) moObj).get("model");
@@ -336,7 +336,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
                     imports.add(createMapping("import", operation.returnBaseType));
                 }
             }
-            List<CodegenParameter> params = new ArrayList<CodegenParameter>();
+            List<CodegenParameter> params = new ArrayList<>();
             if (operation.allParams != null) params.addAll(operation.allParams);
 
             // Check all parameter baseType if there is a necessity to include, include it if not
@@ -375,7 +375,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
     }
 
     private Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, toModelImport(value));
         return customImport;
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
index f6b62cdd1449c7bf0a9e659c9bff327ca33a74e9..4a8063826c8cb9ea93c6694eaef5cea4c49e65e6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
@@ -161,10 +161,10 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("cmake-lists.mustache", "", "CMakeLists.txt"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "utility::datetime");
         typeMapping.put("DateTime", "utility::datetime");
         typeMapping.put("string", "utility::string_t");
@@ -181,7 +181,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "utility::string_t");
         typeMapping.put("ByteArray", "utility::string_t");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");
@@ -255,7 +255,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         CodegenModel codegenModel = super.fromModel(name, model);
 
         Set<String> oldImports = codegenModel.imports;
-        codegenModel.imports = new HashSet<String>();
+        codegenModel.imports = new HashSet<>();
         for (String imp : oldImports) {
             String newImp = toModelImport(imp);
             if (!newImp.isEmpty()) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestbedServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestbedServerCodegen.java
index ca3e6c02f48d798c28d1577d1f0c513345c888ca..3f21f4adf14d408517257988f9dc96c668103e5a 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestbedServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestbedServerCodegen.java
@@ -93,10 +93,10 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("git_push.sh.mustache", "", "git_push.sh"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "std::string");
         typeMapping.put("DateTime", "std::string");
         typeMapping.put("string", "std::string");
@@ -113,7 +113,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "std::string");
         typeMapping.put("ByteArray", "std::string");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");
@@ -129,7 +129,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         // Clean interfaces of ambiguity
         for (Entry<String, CodegenModel> cm : allModels.entrySet()) {
             if (cm.getValue().getInterfaces() != null && !cm.getValue().getInterfaces().isEmpty()) {
-                List<String> newIntf = new ArrayList<String>(cm.getValue().getInterfaces());
+                List<String> newIntf = new ArrayList<>(cm.getValue().getInterfaces());
 
                 for (String intf : allModels.get(cm.getKey()).getInterfaces()) {
                     if (allModels.get(intf).getInterfaces() != null && !allModels.get(intf).getInterfaces().isEmpty()) {
@@ -256,7 +256,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         CodegenModel codegenModel = super.fromModel(name, model);
 
         Set<String> oldImports = codegenModel.imports;
-        codegenModel.imports = new HashSet<String>();
+        codegenModel.imports = new HashSet<>();
         for (String imp : oldImports) {
             String newImp = toModelImport(imp);
             if (!newImp.isEmpty()) {
@@ -285,7 +285,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
-        List<CodegenOperation> newOpList = new ArrayList<CodegenOperation>();
+        List<CodegenOperation> newOpList = new ArrayList<>();
 
         for (CodegenOperation op : operationList) {
             String path = op.path;
@@ -318,7 +318,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
                         final String X_CODEGEN_OTHER_METHODS = "x-codegen-other-methods";
                         List<CodegenOperation> currentOtherMethodList = (List<CodegenOperation>) op1.vendorExtensions.get(X_CODEGEN_OTHER_METHODS);
                         if (currentOtherMethodList == null) {
-                            currentOtherMethodList = new ArrayList<CodegenOperation>();
+                            currentOtherMethodList = new ArrayList<>();
                         }
                         op.operationIdCamelCase = op1.operationIdCamelCase;
                         currentOtherMethodList.add(op);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java
index ef5329ad8eaacaa5747b3cccb6e230a33a4ce31b..bf3f44bde877194ba89deb93e47e40dedaeb2bab 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java
@@ -71,7 +71,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
     }
 
     public void addControllerToAdditionalProperties() {
-        Map<String, String> supportedControllers = new HashMap<String, String>();
+        Map<String, String> supportedControllers = new HashMap<>();
         supportedControllers.put("esp32", "isESP32");
         supportedControllers.put("esp8266", "isESP8266");
         if (supportedControllers.containsKey(controller)) {
@@ -165,7 +165,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
         supportingFiles.add(new SupportingFile("README.mustache", rootFolder, "README.md"));
         supportingFiles.add(new SupportingFile("pre_compiling_bourne.py.mustache", rootFolder, "pre_compiling_bourne.py"));
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -173,7 +173,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
                         "double",
                         "float")
         );
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -183,7 +183,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
                         "std::string")
         );
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
         typeMapping.put("string", "std::string");
         typeMapping.put("integer", "int");
         typeMapping.put("boolean", "bool");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java
index d23bf246caca0225ab1c23d78a45bc4235731741..bda761ee8a3694aeca09389ffd75e81c5deddae7 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java
@@ -71,7 +71,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         embeddedTemplateDir = templateDir = "cpp-tizen-client";
         modelPackage = "";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -79,7 +79,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
                         "double",
                         "float")
         );
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -105,7 +105,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
                         "unsigned", "using", "virtual", "void", "volatile", "wchar_t", "while", "xor", "xor_eq"
                 ));
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         //typeMapping.put("Date", "DateTime");
         //typeMapping.put("DateTime", "DateTime");
@@ -128,7 +128,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         typeMapping.put("UUID", "std::string");
         typeMapping.put("URI", "std::string");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
         supportingFiles.clear();
         supportingFiles.add(new SupportingFile("helpers-header.mustache", sourceFolder, "Helpers.h"));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppUE4ClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppUE4ClientCodegen.java
index 9f3b47c8272c93bd8586ad90d3a982c130304d4f..5eb601f0a0152ead4cead3da9c9d28e02f4ae70b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppUE4ClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppUE4ClientCodegen.java
@@ -39,14 +39,14 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
 
     protected String unrealModuleName = "OpenAPI";
     // Will be treated as pointer
-    protected Set<String> pointerClasses = new HashSet<String>();
+    protected Set<String> pointerClasses = new HashSet<>();
     // source folder where to write the files
     protected String privateFolder = "Private";
     protected String publicFolder = "Public";
     protected String apiVersion = "1.0.0";
-    protected Map<String, String> namespaces = new HashMap<String, String>();
+    protected Map<String, String> namespaces = new HashMap<>();
     // Will be included using the <> syntax, not used in Unreal's coding convention
-    protected Set<String> systemIncludes = new HashSet<String>();
+    protected Set<String> systemIncludes = new HashSet<>();
     protected String cppNamespace = unrealModuleName;
     protected boolean optionalProjectFileFlag = true;
 
@@ -132,7 +132,7 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int32",
@@ -159,7 +159,7 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
             supportingFiles.add(new SupportingFile("module-source.mustache", privateFolder, unrealModuleName + "Module.cpp"));
         }
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         // Maps C++ types during call to getSchemaType, see DefaultCodegen.getSchemaType and not the types/formats
         // defined in openapi specification "array" is also used explicitly in the generator for containers
@@ -188,10 +188,10 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
         typeMapping.put("UUID", "FGuid");
         typeMapping.put("AnyType", "TSharedPtr<FJsonValue>");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("HttpFileInput", "#include \"" + modelNamePrefix + "Helpers.h\"");
 
-        namespaces = new HashMap<String, String>();
+        namespaces = new HashMap<>();
     }
 
     @Override
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CrystalClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CrystalClientCodegen.java
index 250f9672968212aaa14a3ae2acca2c3fde1f22c4..20cb1faec4d4022a6cf1707a073e1718a1509e17 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CrystalClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CrystalClientCodegen.java
@@ -130,7 +130,7 @@ public class CrystalClientCodegen extends DefaultCodegen {
         hideGenerationTimestamp = Boolean.TRUE;
 
         // reserved word. Ref: https://github.com/crystal-lang/crystal/wiki/Crystal-for-Rubyists#available-keywords
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "abstract", "do", "if", "nil?", "select", "union",
                         "alias", "else", "in", "of", "self", "unless",
@@ -557,8 +557,8 @@ public class CrystalClientCodegen extends DefaultCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         objs = super.postProcessOperationsWithModels(objs, allModels);
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java
index 78c1235c9df6c7a550dd8bd983bce82b61aab1b1..e5d7ec6957d332c2fabe6649309ed6c0dc293c43 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java
@@ -116,7 +116,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
          * Reserved words.  Override this with reserved words specific to your language
          * Ref: https://github.com/itsgreggreg/elixir_quick_reference#reserved-words
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "nil",
                         "true",
@@ -164,7 +164,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Integer",
                         "Float",
@@ -182,7 +182,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
         );
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "Integer");
         typeMapping.put("long", "Integer");
         typeMapping.put("number", "Float");
@@ -727,7 +727,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
             }
 
             sb.append("keyword()) :: ");
-            HashSet<String> uniqueResponseTypes = new HashSet<String>();
+            HashSet<String> uniqueResponseTypes = new HashSet<>();
             for (CodegenResponse response : this.responses) {
                 ExtendedCodegenResponse exResponse = (ExtendedCodegenResponse) response;
                 StringBuilder returnEntry = new StringBuilder("");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
index 541456a824e3907e0b2300022f2eddfb1388c320..f60d992727fddc4156e6ac82c32fb2b2aef00a93 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangClientCodegen.java
@@ -311,7 +311,7 @@ public class ErlangClientCodegen extends DefaultCodegen implements CodegenConfig
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> os = (List<CodegenOperation>) operations.get("operation");
-        List<ExtendedCodegenOperation> newOs = new ArrayList<ExtendedCodegenOperation>();
+        List<ExtendedCodegenOperation> newOs = new ArrayList<>();
         Pattern pattern = Pattern.compile("\\{([^\\}]+)\\}");
         for (CodegenOperation o : os) {
             // force http method to lower case
@@ -321,7 +321,7 @@ public class ErlangClientCodegen extends DefaultCodegen implements CodegenConfig
                 o.returnType = "[" + o.returnBaseType + "]";
             }
 
-            ArrayList<String> pathTemplateNames = new ArrayList<String>();
+            ArrayList<String> pathTemplateNames = new ArrayList<>();
             Matcher matcher = pattern.matcher(o.path);
             StringBuffer buffer = new StringBuffer();
             while (matcher.find()) {
@@ -394,7 +394,7 @@ public class ErlangClientCodegen extends DefaultCodegen implements CodegenConfig
     }
 
     class ExtendedCodegenOperation extends CodegenOperation {
-        private List<String> pathTemplateNames = new ArrayList<String>();
+        private List<String> pathTemplateNames = new ArrayList<>();
         private String replacedPathName;
         String arityRequired;
         String arityOptional;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FlashClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FlashClientCodegen.java
index 2dfcbfcafbe8a759f156285f08fb0199ffddff4b..41cd355a61803a632e152ed7e2656482288df921 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FlashClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FlashClientCodegen.java
@@ -106,7 +106,7 @@ public class FlashClientCodegen extends DefaultCodegen implements CodegenConfig
         typeMapping.put("URI", "String");
         typeMapping.put("binary", "File");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("File", "flash.filesystem.File");
 
         // from
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientCodegen.java
index 5f556a45671de375baf8dfe74d5b0f6a9cf31a5c..506de15420c22cc84f26a8ea7117eef76016b37e 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientCodegen.java
@@ -445,8 +445,8 @@ public class GoClientCodegen extends AbstractGoCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         objs = super.postProcessOperationsWithModels(objs, allModels);
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java
index 662cbfce1324a206bf61de04d382e9e0edb3e206..65faaff92c8c2ee5612d211c9e219f042601aa4d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java
@@ -136,8 +136,8 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
     protected Map<String, Map<String, Object>> uniqueParamNameTypes = new HashMap<>();
     protected Map<String, Set<String>> modelMimeTypes = new HashMap<>();
     protected Map<String, String> knownMimeDataTypes = new HashMap<>();
-    protected Set<String> typeNames = new HashSet<String>();
-    protected Set<String> modelTypeNames = new HashSet<String>();
+    protected Set<String> typeNames = new HashSet<>();
+    protected Set<String> modelTypeNames = new HashSet<>();
 
     final private static Pattern CONTAINS_JSON_MIME_PATTERN = Pattern.compile("(?i)application/.*json(;.*)?");
 
@@ -235,7 +235,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
         supportingFiles.add(new SupportingFile("tests/PropMime.mustache", "tests", "PropMime.hs"));
         supportingFiles.add(new SupportingFile("tests/Test.mustache", "tests", "Test.hs"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "String",
@@ -555,7 +555,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
         }
 
         if (!additionalProperties.containsKey(PROP_BASE_MODULE)) {
-            List<String> wordsCaps = new ArrayList<String>();
+            List<String> wordsCaps = new ArrayList<>();
             for (String word : baseTitle.split(" ")) {
                 wordsCaps.add(firstLetterToUpper(word));
             }
@@ -684,7 +684,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
     public void addOperationToGroup(String tag, String resourcePath, Operation operation, CodegenOperation op, Map<String, List<CodegenOperation>> operations) {
         List<CodegenOperation> opList = operations.get(tag);
         if (opList == null || opList.isEmpty()) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(tag, opList);
         }
         // check for operationId uniqueness
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java
index 9887d5c6f1e5bf6568e3790ccaaba7d6aea1f871..b4ecc1bf6e38b6129acdf48b3805ad2063e1a70e 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java
@@ -169,7 +169,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "String",
@@ -286,14 +286,14 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         String[] words = title.split(" ");
 
         // The package name is made by appending the lowercased words of the title interspersed with dashes
-        List<String> wordsLower = new ArrayList<String>();
+        List<String> wordsLower = new ArrayList<>();
         for (String word : words) {
             wordsLower.add(word.toLowerCase(Locale.ROOT));
         }
         String cabalName = joinStrings("-", wordsLower);
 
         // The API name is made by appending the capitalized words of the title
-        List<String> wordsCaps = new ArrayList<String>();
+        List<String> wordsCaps = new ArrayList<>();
         for (String word : words) {
             wordsCaps.add(firstLetterToUpper(word));
         }
@@ -446,7 +446,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
     // IdType is provided by the capture params.
     private List<String> pathToServantRoute(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -462,7 +462,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // Convert the path into a list of servant route components.
-        List<String> pathComponents = new ArrayList<String>();
+        List<String> pathComponents = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
@@ -479,7 +479,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
     // Extract the arguments that are passed in the route path parameters
     private List<String> pathToClientType(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -490,7 +490,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // Convert the path into a list of servant route components.
-        List<String> type = new ArrayList<String>();
+        List<String> type = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellYesodServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellYesodServerCodegen.java
index dea598e049983211af5d94473498e1e54a70c73f..c7a332451419514fc4f9d7f2217791de892eee88 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellYesodServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellYesodServerCodegen.java
@@ -136,7 +136,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
                 )
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "Int",
@@ -359,7 +359,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
 
     private List<String> pathToComponents(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -370,7 +370,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
         }
 
         // Convert the path into a list of yesod path components.
-        List<String> components = new ArrayList<String>();
+        List<String> components = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
@@ -412,7 +412,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
 
         List<Map<String, Object>> routes = (List<Map<String, Object>>) additionalProperties.get("routes");
         if (routes == null) {
-            routes = new ArrayList<Map<String, Object>>();
+            routes = new ArrayList<>();
             additionalProperties.put("routes", routes);
         }
 
@@ -432,10 +432,10 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
         }
 
         if (!found) {
-            Map<String, Object> route = new HashMap<String, Object>();
+            Map<String, Object> route = new HashMap<>();
             route.put("path", path);
             route.put("resource", resource);
-            List<String> methods = new ArrayList<String>();
+            List<String> methods = new ArrayList<>();
             methods.add(op.httpMethod);
             route.put("methods", methods);
             routes.add(route);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JMeterClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JMeterClientCodegen.java
index cec0fdeccaa5189736d71ac159a7afc7d7f4a581..bad912d9a8f6e24c29ed1603014c37787a080f59 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JMeterClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JMeterClientCodegen.java
@@ -133,7 +133,7 @@ public class JMeterClientCodegen extends DefaultCodegen implements CodegenConfig
         /*
          * Reserved words.  Override this with reserved words specific to your language
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "sample1",  // replace with static values
                         "sample2")
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFExtServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFExtServerCodegen.java
index a02e91ad0f8129fc3ca27138aacb2e4fb0409349..03d7066b6e0120d3d85cb2924d55aa62d8099826 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFExtServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFExtServerCodegen.java
@@ -1249,16 +1249,16 @@ public class JavaCXFExtServerCodegen extends JavaCXFServerCodegen implements CXF
                 // did not include the ones we've just added to support the code in the operation bodies. Therefore it
                 // is necessary to recompute the imports and overwrite the existing ones. The code below was copied from
                 // the private DefaultGenerator.processOperations() method to achieve this end.
-                Set<String> allImports = new TreeSet<String>();
+                Set<String> allImports = new TreeSet<>();
                 for (CodegenOperation op : ops) {
                     allImports.addAll(op.imports);
                 }
                 allImports.add("List");
                 allImports.add("Map");
 
-                List<Map<String, String>> imports = new ArrayList<Map<String, String>>();
+                List<Map<String, String>> imports = new ArrayList<>();
                 for (String nextImport : allImports) {
-                    Map<String, String> im = new LinkedHashMap<String, String>();
+                    Map<String, String> im = new LinkedHashMap<>();
                     String mapping = importMapping().get(nextImport);
                     if (mapping == null) {
                         mapping = toModelImport(nextImport);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
index e34a582460f802941a75678f1f7ad64f8fe7a4d7..6c9073d46f455dede6e33d7a058b96cbb9f423ee 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
@@ -818,7 +818,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
                 // for enum model
                 if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                     cm.imports.add(importMapping.get("SerializedName"));
-                    Map<String, String> item = new HashMap<String, String>();
+                    Map<String, String> item = new HashMap<>();
                     item.put("import", importMapping.get("SerializedName"));
                     imports.add(item);
                 }
@@ -864,10 +864,10 @@ public class JavaClientCodegen extends AbstractJavaCodegen
 
                         // add import for Set, HashSet
                         cm.imports.add("Set");
-                        Map<String, String> importsSet = new HashMap<String, String>();
+                        Map<String, String> importsSet = new HashMap<>();
                         importsSet.put("import", "java.util.Set");
                         imports.add(importsSet);
-                        Map<String, String> importsHashSet = new HashMap<String, String>();
+                        Map<String, String> importsHashSet = new HashMap<>();
                         importsHashSet.put("import", "java.util.HashSet");
                         imports.add(importsHashSet);
                     }
@@ -881,7 +881,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
                     imports2Classnames.put("JsonIgnore", "com.fasterxml.jackson.annotation.JsonIgnore");
                     for (Map.Entry<String, String> entry : imports2Classnames.entrySet()) {
                         cm.imports.add(entry.getKey());
-                        Map<String, String> importsItem = new HashMap<String, String>();
+                        Map<String, String> importsItem = new HashMap<>();
                         importsItem.put("import", entry.getValue());
                         imports.add(importsItem);
                     }
@@ -894,9 +894,9 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             Map<String, Object> mo = (Map<String, Object>) _mo;
             CodegenModel cm = (CodegenModel) mo.get("model");
 
-            cm.getVendorExtensions().putIfAbsent("x-implements", new ArrayList<String>());
+            cm.getVendorExtensions().putIfAbsent("x-implements", new ArrayList<>());
             if (JERSEY2.equals(getLibrary()) || NATIVE.equals(getLibrary())) {
-                cm.getVendorExtensions().put("x-implements", new ArrayList<String>());
+                cm.getVendorExtensions().put("x-implements", new ArrayList<>());
 
                 if (cm.oneOf != null && !cm.oneOf.isEmpty() && cm.oneOf.contains("ModelNull")) {
                     // if oneOf contains "null" type
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaInflectorServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaInflectorServerCodegen.java
index 22f1567f3b5aba01af052059084c4a42b08b30ea..d2b1f6e389af85d2fc8dbbb39fd908f4825d149f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaInflectorServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaInflectorServerCodegen.java
@@ -128,7 +128,7 @@ public class JavaInflectorServerCodegen extends AbstractJavaCodegen {
         }
         List<CodegenOperation> opList = operations.get(basePath);
         if (opList == null) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(basePath, opList);
         }
         opList.add(co);
@@ -197,7 +197,7 @@ public class JavaInflectorServerCodegen extends AbstractJavaCodegen {
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaJerseyServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaJerseyServerCodegen.java
index 57ad135e867fb51397974056ed85a3a711c6ce4c..bfbfc4637183e0795e468b6338a41c2f0c289fb8 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaJerseyServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaJerseyServerCodegen.java
@@ -145,7 +145,7 @@ public class JavaJerseyServerCodegen extends AbstractJavaJAXRSServerCodegen {
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMSF4JServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMSF4JServerCodegen.java
index be13c533ebd801c95d729224de3d240bc98ec5a2..3c68202a51fdf8d095052cbe8c168b8018708986 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMSF4JServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMSF4JServerCodegen.java
@@ -133,7 +133,7 @@ public class JavaMSF4JServerCodegen extends AbstractJavaJAXRSServerCodegen {
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java
index b6b3d0bb793017ca9957085c36168889cee6ba37..90a1277c78f7c3219c5d985feab09c9d6b7fa35e 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java
@@ -443,7 +443,7 @@ public class JavaPKMSTServerCodegen extends AbstractJavaCodegen {
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(this.importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", this.importMapping.get("JsonValue"));
                 imports.add(item);
             }
@@ -549,9 +549,9 @@ public class JavaPKMSTServerCodegen extends AbstractJavaCodegen {
                 if (path.readOperations() != null) {
                     for (Operation operation : path.readOperations()) {
                         if (operation.getTags() != null) {
-                            List<Map<String, String>> tags = new ArrayList<Map<String, String>>();
+                            List<Map<String, String>> tags = new ArrayList<>();
                             for (String tag : operation.getTags()) {
-                                Map<String, String> value = new HashMap<String, String>();
+                                Map<String, String> value = new HashMap<>();
                                 value.put("tag", tag);
                                 tags.add(value);
                             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyEapServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyEapServerCodegen.java
index 8698bd98dea6ea00863ffea78b5b3a9834b254ca..783c2538db5d671ea5ec4ef41dcd37ff6e22fcc6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyEapServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyEapServerCodegen.java
@@ -148,7 +148,7 @@ public class JavaResteasyEapServerCodegen extends AbstractJavaJAXRSServerCodegen
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyServerCodegen.java
index 5a86c38ab25ab37b5465f9e1ec1569bbaeac2c6d..eb598acff2966e2fcf4f58a9a88cb08ccb09aee5 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyServerCodegen.java
@@ -159,7 +159,7 @@ public class JavaResteasyServerCodegen extends AbstractJavaJAXRSServerCodegen im
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaUndertowServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaUndertowServerCodegen.java
index 5f44517c5c0a5cae38781f42bc8cd168ef403209..ed1f46df39eea9fcc9950b5017cea3719e08b6a8 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaUndertowServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaUndertowServerCodegen.java
@@ -179,7 +179,7 @@ public class JavaUndertowServerCodegen extends AbstractJavaCodegen {
             // for enum model
             if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                 cm.imports.add(importMapping.get("JsonValue"));
-                Map<String, String> item = new HashMap<String, String>();
+                Map<String, String> item = new HashMap<>();
                 item.put("import", importMapping.get("JsonValue"));
                 imports.add(item);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptApolloClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptApolloClientCodegen.java
index 28028afbc62629585206c3abe818847b1982ac6c..3fc609a146be0ea6eac98ea6f11780be1b9d50e9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptApolloClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptApolloClientCodegen.java
@@ -132,10 +132,10 @@ public class JavascriptApolloClientCodegen extends DefaultCodegen implements Cod
                         "prototype", "String", "toString", "undefined", "valueOf")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("String", "Boolean", "Number", "Array", "Object", "Date", "File", "Blob")
         );
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
 
         instantiationTypes.put("array", "Array");
         instantiationTypes.put("list", "Array");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
index 71f0711bc5d33ec07337a3730014643688e970f9..0f70d46b770ede2f2efe8fa1619d8d2775618f1b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java
@@ -135,10 +135,10 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
                         "prototype", "String", "toString", "undefined", "valueOf")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("String", "Boolean", "Number", "Array", "Object", "Date", "File", "Blob")
         );
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
 
         instantiationTypes.put("array", "Array");
         instantiationTypes.put("set", "Array");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClosureAngularClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClosureAngularClientCodegen.java
index e66420e26355e62f0230070e952b52792feed591..92824ba61d9a721f378c8420dfa67c71bba5f2cb 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClosureAngularClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClosureAngularClientCodegen.java
@@ -55,7 +55,7 @@ public class JavascriptClosureAngularClientCodegen extends DefaultCodegen implem
             "short", "try", "char", "final", "interface", "static", "void",
             "class", "finally", "const", "super", "while"));
 
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
             "string",
             "boolean",
             "number",
@@ -64,7 +64,7 @@ public class JavascriptClosureAngularClientCodegen extends DefaultCodegen implem
             "Date"));
         instantiationTypes.put("array", "Array");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("Array", "Array");
         typeMapping.put("array", "Array");
         typeMapping.put("List", "Array");
@@ -86,8 +86,8 @@ public class JavascriptClosureAngularClientCodegen extends DefaultCodegen implem
         typeMapping.put("map", "Object");
         typeMapping.put("DateTime", "Date");
 
-        importMapping = new HashMap<String, String>();
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        importMapping = new HashMap<>();
+        defaultIncludes = new HashSet<>(Arrays.asList(
             "Object",
             "Array",
             "Blob"
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptFlowtypedClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptFlowtypedClientCodegen.java
index da4193b017346ad70f15e7541e0e82fba0026f57..3d09506f68f3a4e9fc7c043182d439698c25c7c7 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptFlowtypedClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptFlowtypedClientCodegen.java
@@ -64,7 +64,7 @@ public class JavascriptFlowtypedClientCodegen extends AbstractTypeScriptClientCo
                 "Math", "NaN", "Number", "Object",
                 "prototype", "String", "toString", "undefined", "valueOf"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("string", "boolean", "number", "Array", "Object", "Date", "File", "Blob")
         );
 
@@ -95,7 +95,7 @@ public class JavascriptFlowtypedClientCodegen extends AbstractTypeScriptClientCo
         typeMapping.put("UUID", "string");
         typeMapping.put("URI", "string");
 
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
         outputFolder = "generated-code/javascript-flowtyped";
         embeddedTemplateDir = templateDir = "Javascript-Flowtyped";
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/K6ClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/K6ClientCodegen.java
index 002084bc6165479541fc9f21131d76bc2528c302..a0a78857f4aab1e8ac30276f6260b17745d43809 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/K6ClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/K6ClientCodegen.java
@@ -141,7 +141,7 @@ public class K6ClientCodegen extends DefaultCodegen implements CodegenConfig {
                             .map(x -> quoteExample(
                                     StringEscapeUtils.escapeEcmaScript(
                                             String.valueOf(x.getValue()))))
-                            .collect(Collectors.toCollection(() -> new TreeSet<String>()));
+                            .collect(Collectors.toCollection(() -> new TreeSet<>()));
 
                     if (!exampleValues.isEmpty()) {
 
@@ -412,7 +412,7 @@ public class K6ClientCodegen extends DefaultCodegen implements CodegenConfig {
                 List<Parameter> queryParams = new ArrayList<>();
                 List<Parameter> bodyOrFormParams = new ArrayList<>();
                 List<k6Check> k6Checks = new ArrayList<>();
-                Set<String> imports = new HashSet<String>();
+                Set<String> imports = new HashSet<>();
 
                 final Operation operation = methodOperation.getValue();
                 final PathItem.HttpMethod method = methodOperation.getKey();
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KtormSchemaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KtormSchemaCodegen.java
index 2db0bd7af887c4fc9adc86941eebb2c852da85be..4392c28f9eed7d4f65d5de3f711af3a8e237004f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KtormSchemaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KtormSchemaCodegen.java
@@ -58,7 +58,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
     protected String primaryKeyConvention = "id";
     protected boolean addSurrogateKey = false;
 
-    protected Map<String, String> sqlTypeMapping = new HashMap<String, String>();
+    protected Map<String, String> sqlTypeMapping = new HashMap<>();
 
     // https://ktorm.liuwj.me/api-docs/me.liuwj.ktorm.schema/index.html
     protected static class SqlType {
@@ -136,7 +136,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
                 )
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "kotlin.String");
         typeMapping.put("boolean", "kotlin.Boolean");
         typeMapping.put("integer", "kotlin.Int");
@@ -290,8 +290,8 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
             String tableName = toTableName(modelName);
             String modelDescription = model.getDescription();
             Map<String, Object> modelVendorExtensions = model.getVendorExtensions();
-            Map<String, Object> ktormSchema = new HashMap<String, Object>();
-            Map<String, Object> tableDefinition = new HashMap<String, Object>();
+            Map<String, Object> ktormSchema = new HashMap<>();
+            Map<String, Object> tableDefinition = new HashMap<>();
 
             if (getIdentifierNamingConvention().equals("snake_case") && !modelName.equals(tableName)) {
                 // add original name in table comment
@@ -347,7 +347,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      */
     @Override
     public void postProcessModelProperty(CodegenModel model, CodegenProperty property) {
-        Map<String, Object> relationDefinition = new HashMap<String, Object>();
+        Map<String, Object> relationDefinition = new HashMap<>();
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
         KtormSchema ktormSchema = new KtormSchema();
         String baseName = property.getBaseName();
@@ -416,7 +416,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processIntegerTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -464,7 +464,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processRealTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -505,7 +505,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processBooleanTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -530,7 +530,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processStringTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -569,7 +569,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processDateTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -594,7 +594,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processJsonTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -621,7 +621,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param ktormSchema schema
      */
     public void processUnknownTypeProperty(CodegenModel model, CodegenProperty property, String description, KtormSchema ktormSchema) {
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = toColumnName(baseName);
         String dataType = property.getDataType();
@@ -647,7 +647,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
      * @param columnDefinition resulting column definition dictionary
      */
     public void processTypeArgs(String dataType, String dataFormat, Object min, Object max, Map<String, Object> columnDefinition) {
-        HashMap<String, Object> a = new HashMap<String, Object>();
+        HashMap<String, Object> a = new HashMap<>();
         SqlTypeArgs args = new SqlTypeArgs();
         toColumnTypeArgs(dataType, dataFormat, min, max, args);
         a.put("isPrimitive", args.isPrimitive);
@@ -970,7 +970,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
             default:
                 sqlDefault = "NULL";
         }
-        Map<String, Object> args = new HashMap<String, Object>();
+        Map<String, Object> args = new HashMap<>();
         processTypeArgs(sqlType, null, null, null, args);
         args.put("defaultValue", sqlDefault);
         return args;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/LuaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/LuaClientCodegen.java
index 40f2cb23c056da054797512b0fd72457b61a8fbc..795b829036a1faaaa48d746ad0d514b5ae815000 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/LuaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/LuaClientCodegen.java
@@ -111,13 +111,13 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "nil",
                         "string",
@@ -150,7 +150,7 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
         typeMapping.put("ByteArray", "string");
         typeMapping.put("object", "TODO_OBJECT_MAPPING");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("time.Time", "time");
         importMapping.put("*os.File", "os");
         importMapping.put("os", "io/ioutil");
@@ -508,7 +508,7 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MysqlSchemaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MysqlSchemaCodegen.java
index fa217e1635fa230801a1364904ad0e35da78a147..b514e7e8d1298b1efce2a05147384f52ba69eb98 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MysqlSchemaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MysqlSchemaCodegen.java
@@ -41,19 +41,19 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
     public static final Integer ENUM_MAX_ELEMENTS = 65535;
     public static final Integer IDENTIFIER_MAX_LENGTH = 64;
 
-    protected Vector<String> mysqlNumericTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlNumericTypes = new Vector<>(Arrays.asList(
             "BIGINT", "BIT", "BOOL", "BOOLEAN", "DEC", "DECIMAL", "DOUBLE", "DOUBLE PRECISION", "FIXED", "FLOAT", "INT", "INTEGER", "MEDIUMINT", "NUMERIC", "REAL", "SMALLINT", "TINYINT"
     ));
 
-    protected Vector<String> mysqlDateAndTimeTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlDateAndTimeTypes = new Vector<>(Arrays.asList(
             "DATE", "DATETIME", "TIME", "TIMESTAMP", "YEAR"
     ));
 
-    protected Vector<String> mysqlStringTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlStringTypes = new Vector<>(Arrays.asList(
             "BINARY", "BLOB", "CHAR", "CHAR BYTE", "CHARACTER", "ENUM", "LONGBLOB", "LONGTEXT", "MEDIUMBLOB", "MEDIUMTEXT", "SET", "TEXT", "TINYBLOB", "TINYTEXT", "VARBINARY", "VARCHAR"
     ));
 
-    protected Vector<String> mysqlSpatialTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlSpatialTypes = new Vector<>(Arrays.asList(
             "GEOMETRY", "GEOMETRYCOLLECTION", "LINESTRING", "MULTILINESTRING", "MULTIPOINT", "MULTIPOLYGON", "POINT", "POLYGON"
     ));
 
@@ -125,7 +125,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
         );
 
         // all types can be threaded as primitives except array, object and refs
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "boolean",
@@ -263,8 +263,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
             String tableName = this.toTableName(modelName);
             String modelDescription = model.getDescription();
             Map<String, Object> modelVendorExtensions = model.getVendorExtensions();
-            Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-            Map<String, Object> tableDefinition = new HashMap<String, Object>();
+            Map<String, Object> mysqlSchema = new HashMap<>();
+            Map<String, Object> tableDefinition = new HashMap<>();
 
             if (this.getIdentifierNamingConvention().equals("snake_case") && !modelName.equals(tableName)) {
                 // add original name in table comment
@@ -325,8 +325,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processIntegerTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -417,8 +417,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processDecimalTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -507,8 +507,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processBooleanTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -562,8 +562,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processStringTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -645,8 +645,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processDateTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         String dataType = property.getDataType();
@@ -698,8 +698,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processJsonTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         String dataType = property.getDataType();
@@ -755,8 +755,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processUnknownTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         Boolean required = property.getRequired();
@@ -806,7 +806,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      * @return generated codegen property
      */
     public HashMap<String, Object> toCodegenMysqlDataTypeArgument(Object value) {
-        HashMap<String, Object> arg = new HashMap<String, Object>();
+        HashMap<String, Object> arg = new HashMap<>();
         if (value instanceof String) {
             arg.put("isString", true);
             arg.put("isFloat", false);
@@ -838,7 +838,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      * @return generated codegen property
      */
     public HashMap<String, Object> toCodegenMysqlDataTypeDefault(String defaultValue, String mysqlDataType) {
-        HashMap<String, Object> defaultMap = new HashMap<String, Object>();
+        HashMap<String, Object> defaultMap = new HashMap<>();
         if (defaultValue == null || defaultValue.toUpperCase(Locale.ROOT).equals("NULL")) {
             defaultMap.put("defaultValue", "NULL");
             defaultMap.put("isString", false);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NimClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NimClientCodegen.java
index c81bccd718a3c169918a27f5ec428bf4362c05ab..572cbacc66f8725dc7855608b6d6383ba8fd2e5b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NimClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NimClientCodegen.java
@@ -117,13 +117,13 @@ public class NimClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "array"
                 )
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "int",
                         "int8",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ObjcClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ObjcClientCodegen.java
index 562f1a5b3fd12ae919967b517018b17c534452c2..0075bcb8a5754bd3f27403eee6a80efd0213fffe 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ObjcClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ObjcClientCodegen.java
@@ -43,7 +43,7 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
     public static final String DEFAULT_LICENSE = "Proprietary";
     public static final String CORE_DATA = "coreData";
 
-    protected Set<String> foundationClasses = new HashSet<String>();
+    protected Set<String> foundationClasses = new HashSet<>();
     protected String podName = "OpenAPIClient";
     protected String podVersion = "1.0.0";
     protected String classPrefix = "OAI";
@@ -60,7 +60,7 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
 
     protected boolean generateCoreData = false;
 
-    protected Set<String> advancedMappingTypes = new HashSet<String>();
+    protected Set<String> advancedMappingTypes = new HashSet<>();
 
     public ObjcClientCodegen() {
         super();
@@ -185,9 +185,9 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
                         "description", "class"
                 ));
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
-        foundationClasses = new HashSet<String>(
+        foundationClasses = new HashSet<>(
                 Arrays.asList(
                         "NSNumber",
                         "NSObject",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpMezzioPathHandlerServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpMezzioPathHandlerServerCodegen.java
index c45a8af07ca90b8ba4061266e5d7f9ca207a166f..8d129f6ff0bfb912bbe256b948d0c8ed9c5476c0 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpMezzioPathHandlerServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpMezzioPathHandlerServerCodegen.java
@@ -145,7 +145,7 @@ public class PhpMezzioPathHandlerServerCodegen extends AbstractPhpCodegen {
     public void addOperationToGroup(String tag, String resourcePath, Operation operation, CodegenOperation co, Map<String, List<CodegenOperation>> operations) {
         List<CodegenOperation> opList = operations.get(resourcePath);
         if (opList == null) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(resourcePath, opList);
         }
         //ignore duplicate operation ids - that means that operation has several tags
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSilexServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSilexServerCodegen.java
index 3c33950a0341576e3f79e241d1c89c3cd614554a..a6efee11fb18f604e8ad3aa1724be394ac3541f2 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSilexServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSilexServerCodegen.java
@@ -90,7 +90,7 @@ public class PhpSilexServerCodegen extends DefaultCodegen implements CodegenConf
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "boolean",
                         "int",
@@ -108,7 +108,7 @@ public class PhpSilexServerCodegen extends DefaultCodegen implements CodegenConf
         instantiationTypes.put("map", "map");
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("float", "float");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
index 17d970d39c52b9dd78109a7c32e35f51bf7701c1..f6e3f1c6c19945c4e3dae2fdecb6b21c4de8ff51 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java
@@ -113,7 +113,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         outputFolder = "generated-code" + File.separator + "php";
         apiTemplateFiles.put("api_controller.mustache", ".php");
         modelTestTemplateFiles.put("testing/model_test.mustache", ".php");
-        apiTestTemplateFiles = new HashMap<String, String>();
+        apiTestTemplateFiles = new HashMap<>();
         apiTestTemplateFiles.put("testing/api_test.mustache", ".php");
         embeddedTemplateDir = templateDir = "php-symfony";
 
@@ -139,7 +139,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         );
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -157,7 +157,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "\\DateTime",
                         "UploadedFile"
@@ -173,7 +173,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         additionalProperties.put("primitives", primitives);
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("decimal", "float");
@@ -370,13 +370,13 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         // Type-hintable primitive types
         // ref: http://php.net/manual/en/functions.arguments.php#functions.arguments.type-declaration
         if (phpLegacySupport) {
-            typeHintable = new HashSet<String>(
+            typeHintable = new HashSet<>(
                     Arrays.asList(
                             "array"
                     )
             );
         } else {
-            typeHintable = new HashSet<String>(
+            typeHintable = new HashSet<>(
                     Arrays.asList(
                             "array",
                             "bool",
@@ -396,7 +396,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         operations.put("controllerName", toControllerName((String) operations.get("pathPrefix")));
         operations.put("symfonyService", toSymfonyService((String) operations.get("pathPrefix")));
 
-        List<CodegenSecurity> authMethods = new ArrayList<CodegenSecurity>();
+        List<CodegenSecurity> authMethods = new ArrayList<>();
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
 
         for (CodegenOperation op : operationList) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellClientCodegen.java
index 58e12fff70150a27de5f60f6243f5c28d624f223..0d081fb8b0507928f1a8ab0577ac820c2d74615d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellClientCodegen.java
@@ -109,7 +109,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         modelPackage = packageName + File.separator + "Model";
 
         // https://blogs.msdn.microsoft.com/powershell/2010/01/07/how-objects-are-sent-to-and-from-remote-sessions/
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
                 "Byte",
                 "SByte",
                 "Byte[]",
@@ -136,9 +136,9 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Version"
         ));
 
-        commonVerbs = new HashMap<String, String>();
+        commonVerbs = new HashMap<>();
 
-        Map<String, List<String>> verbMappings = new HashMap<String, List<String>>();
+        Map<String, List<String>> verbMappings = new HashMap<>();
 
         // common
         verbMappings.put("Add", Arrays.asList("Append", "Attach", "Concatenate", "Insert"));
@@ -266,7 +266,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
             }
         }
 
-        powershellVerbs = new HashSet<String>(Arrays.asList(
+        powershellVerbs = new HashSet<>(Arrays.asList(
                 "Add",
                 "Clear",
                 "Close",
@@ -368,9 +368,9 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Use"
         ));
 
-        methodNames = new HashSet<String>();
+        methodNames = new HashSet<>();
 
-        nullablePrimitives = new HashSet<String>(Arrays.asList(
+        nullablePrimitives = new HashSet<>(Arrays.asList(
                 "System.Nullable[Byte]",
                 "System.Nullable[SByte]",
                 "System.Nullable[Int16]",
@@ -386,7 +386,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         ));
 
         // list of reserved words - must be in lower case
-        reservedWords = new HashSet<String>(Arrays.asList(
+        reservedWords = new HashSet<>(Arrays.asList(
                 // https://richardspowershellblog.wordpress.com/2009/05/02/powershell-reserved-words/
                 "begin",
                 "break",
@@ -456,7 +456,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "true"
         ));
 
-        paramNameReservedWords = new HashSet<String>(Arrays.asList(
+        paramNameReservedWords = new HashSet<>(Arrays.asList(
                 "args",
                 "error",
                 "executioncontext",
@@ -480,7 +480,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "true"
         ));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        defaultIncludes = new HashSet<>(Arrays.asList(
                 "Byte",
                 "SByte",
                 "Byte[]",
@@ -507,7 +507,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Version"
         ));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "String");
         typeMapping.put("boolean", "Boolean");
         typeMapping.put("integer", "Int32");
@@ -1012,8 +1012,8 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
     @Override
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java
index 02a01627dd68db383f81ec6f47959dceca0d2068..f04a58fcf42693d5487fc656f4ff58b3f5681aac 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java
@@ -86,13 +86,13 @@ public class ProtobufSchemaCodegen extends DefaultCodegen implements CodegenConf
         modelPackage = "messages";
         apiPackage = "services";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java
index 7b66ec98a396b4be11d9ac06db3a09e63b4589a4..6e77cce55034290852c3620d769bf5850d819bed 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java
@@ -611,12 +611,12 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         ComposedSchema cs = (ComposedSchema) schema;
 
         // these are the properties that are from properties in self cs or cs allOf
-        Map<String, Schema> selfProperties = new LinkedHashMap<String, Schema>();
-        List<String> selfRequired = new ArrayList<String>();
+        Map<String, Schema> selfProperties = new LinkedHashMap<>();
+        List<String> selfRequired = new ArrayList<>();
 
         // these are the properties that are from properties in cs oneOf or cs anyOf
-        Map<String, Schema> otherProperties = new LinkedHashMap<String, Schema>();
-        List<String> otherRequired = new ArrayList<String>();
+        Map<String, Schema> otherProperties = new LinkedHashMap<>();
+        List<String> otherRequired = new ArrayList<>();
 
         List<Schema> oneOfanyOfSchemas = new ArrayList<>();
         List<Schema> oneOf = cs.getOneOf();
@@ -631,7 +631,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
             Schema refSchema = ModelUtils.getReferencedSchema(this.openAPI, sc);
             addProperties(otherProperties, otherRequired, refSchema);
         }
-        Set<String> otherRequiredSet = new HashSet<String>(otherRequired);
+        Set<String> otherRequiredSet = new HashSet<>(otherRequired);
 
         List<Schema> allOf = cs.getAllOf();
         if ((schema.getProperties() != null && !schema.getProperties().isEmpty()) || allOf != null) {
@@ -641,7 +641,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         if (result.discriminator != null) {
             selfRequired.add(result.discriminator.getPropertyBaseName());
         }
-        Set<String> selfRequiredSet = new HashSet<String>(selfRequired);
+        Set<String> selfRequiredSet = new HashSet<>(selfRequired);
 
         List<CodegenProperty> reqVars = result.getRequiredVars();
         List<CodegenProperty> reqVarsThatMustBeOptional = new ArrayList<>();
@@ -668,7 +668,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
     protected void addParentContainer(CodegenModel model, String name, Schema schema) {
         super.addParentContainer(model, name, schema);
 
-        List<String> referencedModelNames = new ArrayList<String>();
+        List<String> referencedModelNames = new ArrayList<>();
         model.dataType = getTypeString(schema, "", "", referencedModelNames);
     }
 
@@ -688,7 +688,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         if (cm.requiredVars.size() > 0 && (cm.oneOf.size() > 0 || cm.anyOf.size() > 0)) {
             fixComposedSchemaRequiredVars(sc, cm);
         }
-        ArrayList<List<CodegenProperty>> listOfLists = new ArrayList<List<CodegenProperty>>();
+        ArrayList<List<CodegenProperty>> listOfLists = new ArrayList<>();
         listOfLists.add(cm.requiredVars);
         listOfLists.add(cm.optionalVars);
         for (List<CodegenProperty> cpList : listOfLists) {
@@ -940,7 +940,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
             // store it in codegenModel.additionalPropertiesType.
             // The 'addProps' may be a reference, getTypeDeclaration will resolve
             // the reference.
-            List<String> referencedModelNames = new ArrayList<String>();
+            List<String> referencedModelNames = new ArrayList<>();
             getTypeString(addProps, "", "", referencedModelNames);
             if (referencedModelNames.size() != 0) {
                 // Models that are referenced in the 'additionalPropertiesType' keyword
@@ -1493,7 +1493,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
     protected Map<String, Schema> getModelNameToSchemaCache() {
         if (modelNameToSchemaCache == null) {
             // Create a cache to efficiently lookup schema based on model name.
-            Map<String, Schema> m = new HashMap<String, Schema>();
+            Map<String, Schema> m = new HashMap<>();
             ModelUtils.getSchemas(openAPI).forEach((key, schema) -> {
                 m.put(toModelName(key), schema);
             });
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
index 6ee1131973e916de84ed6f57f0cc85b50b5105f3..beba7698daf5d92263d04ed7b1532287fa8371fb 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
@@ -229,7 +229,7 @@ public class PythonFastAPIServerCodegen extends AbstractPythonCodegen {
             }
         }
 
-        objs.put("securityImports", new ArrayList<String>(securityImports));
+        objs.put("securityImports", new ArrayList<>(securityImports));
 
         return objs;
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonLegacyClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonLegacyClientCodegen.java
index 138b1c543566300355ef1a56cb88f6da506f8931..74e8f80fb2e7c5789a1d44de85550f82cde909c6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonLegacyClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonLegacyClientCodegen.java
@@ -113,7 +113,7 @@ public class PythonLegacyClientCodegen extends AbstractPythonCodegen implements
                         "return", "def", "for", "lambda", "try", "self", "nonlocal", "None", "True",
                         "False", "async", "await"));
 
-        regexModifiers = new HashMap<Character, String>();
+        regexModifiers = new HashMap<>();
         regexModifiers.put('i', "IGNORECASE");
         regexModifiers.put('l', "LOCALE");
         regexModifiers.put('m', "MULTILINE");
@@ -321,7 +321,7 @@ public class PythonLegacyClientCodegen extends AbstractPythonCodegen implements
             }
 
             String regex = pattern.substring(1, i).replace("'", "\\'");
-            List<String> modifiers = new ArrayList<String>();
+            List<String> modifiers = new ArrayList<>();
 
             for (char c : pattern.substring(i).toCharArray()) {
                 if (regexModifiers.containsKey(c)) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java
index 04fea6b122d9bd1b25782214a06e4fe7dd12477a..76e334311c68d93c598802fb86c05ec91469f599 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java
@@ -45,7 +45,7 @@ public class RClientCodegen extends DefaultCodegen implements CodegenConfig {
     protected String testFolder = "tests/testthat";
     protected boolean returnExceptionOnFailure = false;
     protected String exceptionPackage = "default";
-    protected Map<String, String> exceptionPackages = new LinkedHashMap<String, String>();
+    protected Map<String, String> exceptionPackages = new LinkedHashMap<>();
 
     public static final String EXCEPTION_PACKAGE = "exceptionPackage";
     public static final String USE_DEFAULT_EXCEPTION = "useDefaultExceptionHandling";
@@ -479,7 +479,7 @@ public class RClientCodegen extends DefaultCodegen implements CodegenConfig {
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
@@ -690,7 +690,7 @@ public class RClientCodegen extends DefaultCodegen implements CodegenConfig {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> objectMap = (Map<String, Object>) objs.get("operations");
 
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
             CodegenModel m = (CodegenModel) h.get("model");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
index f7d5a20e079e63760d12ab9eec93b09dc7d27540..4829d5aa9b041b60d44a4d4b08eeab518e6abe06 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
@@ -574,8 +574,8 @@ public class RubyClientCodegen extends AbstractRubyCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         objs = super.postProcessOperationsWithModels(objs, allModels);
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java
index 6ca7dd832d0634f74c3a04db502919d14a11f367..265a9afc20805c3f4751375d618ad4233afce970 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java
@@ -124,13 +124,13 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "i8", "i16", "i32", "i64",
                         "u8", "u16", "u32", "u64",
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java
index cc8db68a3168fe88468f245de721d897e7102db7..98c554003856df7dab710df52fb5a7e9007d5106 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java
@@ -53,7 +53,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
 
     private final Logger LOGGER = LoggerFactory.getLogger(RustServerCodegen.class);
 
-    private HashMap<String, String> modelXmlNames = new HashMap<String, String>();
+    private HashMap<String, String> modelXmlNames = new HashMap<>();
 
     private static final String NO_FORMAT = "%%NO_FORMAT";
 
@@ -160,13 +160,13 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "char",
@@ -213,7 +213,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         typeMapping.put("object", "serde_json::Value");
         typeMapping.put("AnyType", "serde_json::Value");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
         cliOptions.clear();
         cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME,
@@ -685,7 +685,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         if (op.isCallbackRequest) {
             formatPath = formatPath.substring(1); // Callback paths are absolute so strip initial '/'
 
-            List<String> params = new ArrayList<String>();
+            List<String> params = new ArrayList<>();
 
             Matcher match = Pattern.compile("\\{\\$[^}{]*\\}").matcher(op.path);
 
@@ -716,7 +716,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         // "pathSetMap", which we'll add to the source document that will be
         // processed by the templates.
         if (!found) {
-            Map<String, String> pathSetEntry = new HashMap<String, String>();
+            Map<String, String> pathSetEntry = new HashMap<>();
             pathSetEntry.put("path", op.path);
             pathSetEntry.put("PATH_ID", pathId);
 
@@ -769,13 +769,13 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         // Determine the types that this operation produces. `getProducesInfo`
         // simply lists all the types, and then we add the correct imports to
         // the generated library.
-        List<String> produces = new ArrayList<String>(getProducesInfo(openAPI, operation));
+        List<String> produces = new ArrayList<>(getProducesInfo(openAPI, operation));
         boolean producesXml = false;
         boolean producesPlainText = false;
         if (produces != null && !produces.isEmpty()) {
-            List<Map<String, String>> c = new ArrayList<Map<String, String>>();
+            List<Map<String, String>> c = new ArrayList<>();
             for (String mimeType : produces) {
-                Map<String, String> mediaType = new HashMap<String, String>();
+                Map<String, String> mediaType = new HashMap<>();
 
                 if (isMimetypeXml(mimeType)) {
                     additionalProperties.put("usesXml", true);
@@ -1267,7 +1267,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         Map<String, Object> newObjs = super.postProcessAllModels(objs);
 
         //Index all CodegenModels by model name.
-        HashMap<String, CodegenModel> allModels = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> allModels = new HashMap<>();
         for (Entry<String, Object> entry : objs.entrySet()) {
             String modelName = toModelName(entry.getKey());
             Map<String, Object> inner = (Map<String, Object>) entry.getValue();
@@ -1353,7 +1353,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
                 return a.getValue().get("path").compareTo(b.getValue().get("path"));
             }
         });
-        List pathSet = new ArrayList<Map<String, String>>();
+        List pathSet = new ArrayList<>();
         int index = 0;
         for (Map.Entry<String, Map<String, String>> pathSetEntry : pathSetEntryList) {
             Map<String, String> pathSetEntryValue = pathSetEntry.getValue();
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaAkkaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaAkkaClientCodegen.java
index e646f0127bb25948abd259ec5236f88f982be507..13216effe7e89f0198272bf2815fcea2e831f60c 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaAkkaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaAkkaClientCodegen.java
@@ -209,7 +209,7 @@ public class ScalaAkkaClientCodegen extends AbstractScalaCodegen implements Code
             try {
                 @SuppressWarnings("unchecked")
                 Map<String, ArrayList<CodegenOperation>> opsMap = (Map<String, ArrayList<CodegenOperation>>) objs.get("operations");
-                HashSet<Integer> unknownCodes = new HashSet<Integer>();
+                HashSet<Integer> unknownCodes = new HashSet<>();
                 for (CodegenOperation operation : opsMap.get("operation")) {
                     for (CodegenResponse response : operation.responses) {
                         if ("default".equals(response.code)) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaFinchServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaFinchServerCodegen.java
index 6194ba802a096fa49abc5cf700d5005e7dd628cc..146ddf06ccf587b28148c2e74a83408cbaf53806 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaFinchServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaFinchServerCodegen.java
@@ -87,7 +87,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
                         "native")
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "Int",
                         "Long",
@@ -107,7 +107,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
                         "Map")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "String");
         typeMapping.put("boolean", "Boolean");
         typeMapping.put("integer", "Int");
@@ -158,7 +158,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
         supportingFiles.add(new SupportingFile("endpoint.mustache", sourceFolder, "endpoint.scala"));
         supportingFiles.add(new SupportingFile("errors.mustache", sourceFolder, "errors.scala"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "Boolean",
@@ -175,7 +175,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
         instantiationTypes.put("array", "ArrayList");
         instantiationTypes.put("map", "HashMap");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
         importMapping.put("File", "java.io.File");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaGatlingCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaGatlingCodegen.java
index 7098f0d591d967b5e8619873fc311ce48ca44e7b..d705b55355dfae8dbf040fd1aa9b9a06bc6faa4a 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaGatlingCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaGatlingCodegen.java
@@ -178,7 +178,7 @@ public class ScalaGatlingCodegen extends AbstractScalaCodegen implements Codegen
 
         importMapping.put("Date", "java.util.Date");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("enum", "NSString");
         typeMapping.put("array", "List");
         typeMapping.put("set", "Set");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaHttpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaHttpClientCodegen.java
index de88700730824f5df75b766d9565c09c839a7ffa..362108fa8a8e38972f8d9c084640b2788653e239 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaHttpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaHttpClientCodegen.java
@@ -112,7 +112,7 @@ public class ScalaHttpClientCodegen extends AbstractScalaCodegen implements Code
         setDateLibrary("legacy",true);
         importMapping.put("Date", "java.util.Date");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("enum", "NSString");
         typeMapping.put("array", "List");
         typeMapping.put("set", "Set");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaLagomServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaLagomServerCodegen.java
index 36ec66b3712aeeb8d67baeea97ce58cb83331e34..5c733b36540de876b3febaee1b4d0477d899f3aa 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaLagomServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaLagomServerCodegen.java
@@ -192,7 +192,7 @@ public class ScalaLagomServerCodegen extends AbstractScalaCodegen implements Cod
                 // for enum model
                 if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
                     cm.imports.add(importMapping.get("SerializedName"));
-                    Map<String, String> item = new HashMap<String, String>();
+                    Map<String, String> item = new HashMap<>();
                     item.put("import", importMapping.get("SerializedName"));
                     imports.add(item);
                 }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java
index dd0dca689fb750e8df992aa3adeddc45e39cfe5b..859f02aba3cd32749bd925e015d7322c45ee8957 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java
@@ -249,7 +249,7 @@ public class ScalaSttpClientCodegen extends AbstractScalaCodegen implements Code
     @SuppressWarnings({"unchecked"})
     private void postProcessUpdateImports(final Map<String, Object> models) {
         final String prefix = modelPackage() + ".";
-        Map<String, Object> enumRefs = new HashMap<String, Object>();
+        Map<String, Object> enumRefs = new HashMap<>();
         for (Map.Entry<String, Object> entry : models.entrySet()) {
             CodegenModel model = ModelUtils.getModelByName(entry.getKey(), models);
             if (model.isEnum) {
@@ -322,7 +322,7 @@ public class ScalaSttpClientCodegen extends AbstractScalaCodegen implements Code
             try {
                 @SuppressWarnings("unchecked")
                 Map<String, ArrayList<CodegenOperation>> opsMap = (Map<String, ArrayList<CodegenOperation>>) objs.get("operations");
-                HashSet<Integer> unknownCodes = new HashSet<Integer>();
+                HashSet<Integer> unknownCodes = new HashSet<>();
                 for (CodegenOperation operation : opsMap.get("operation")) {
                     for (CodegenResponse response : operation.responses) {
                         if ("default".equals(response.code)) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalatraServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalatraServerCodegen.java
index 8cd1e3cc0b6a54ef366b832d5009e49fa3c2a996..4a270fcec9f6e87321c332896b28a18f9e83a145 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalatraServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalatraServerCodegen.java
@@ -57,7 +57,7 @@ public class ScalatraServerCodegen extends AbstractScalaCodegen implements Codeg
         apiPackage = "org.openapitools.server.api";
         modelPackage = "org.openapitools.server.model";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "Int",
                         "Long",
@@ -118,7 +118,7 @@ public class ScalatraServerCodegen extends AbstractScalaCodegen implements Codeg
         supportingFiles.add(new SupportingFile("project/plugins.sbt", "project", "plugins.sbt"));
         supportingFiles.add(new SupportingFile("sbt", "", "sbt"));
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
         importMapping.put("File", "java.io.File");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalazClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalazClientCodegen.java
index 8f3971bd73956986187cba192f8ab2f51d0d9dd4..e206de894b4c36827a99443a8ae696c6e169c0bf 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalazClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalazClientCodegen.java
@@ -104,7 +104,7 @@ public class ScalazClientCodegen extends AbstractScalaCodegen implements Codegen
         importMapping.put("LocalDate", "org.joda.time.LocalDate");
         importMapping.put("LocalTime", "org.joda.time.LocalTime");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("enum", "NSString");
         typeMapping.put("array", "List");
         typeMapping.put("set", "Set");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtml2Generator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtml2Generator.java
index a3c9efaab5e75a4aad1fd0c8648cb6342580560e..523c7de0d09479b4d008a5730eb0fa958e3fe768 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtml2Generator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtml2Generator.java
@@ -67,7 +67,7 @@ public class StaticHtml2Generator extends DefaultCodegen implements CodegenConfi
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "htmlDocs2";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -100,10 +100,10 @@ public class StaticHtml2Generator extends DefaultCodegen implements CodegenConfi
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.html"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
-        importMapping = new HashMap<String, String>();
+        languageSpecificPrimitives = new HashSet<>();
+        importMapping = new HashMap<>();
     }
 
     @Override
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java
index 3804de3160a8849d3de4164319ef0507fe6e0585..7f236d70843c31d09cb33f67810ea11452b3464a 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java
@@ -54,7 +54,7 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "htmlDocs";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -79,10 +79,10 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.html"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
-        importMapping = new HashMap<String, String>();
+        languageSpecificPrimitives = new HashSet<>();
+        importMapping = new HashMap<>();
     }
 
     /**
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift4Codegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift4Codegen.java
index c3efed9445469df17496028163c19b1e5154ffe5..7b259bf5b4bdab0710ac80778e05603f99e7d4a9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift4Codegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift4Codegen.java
@@ -288,7 +288,7 @@ public class Swift4Codegen extends DefaultCodegen implements CodegenConfig {
         // Get the properties for the parent and child models
         final List<CodegenProperty> parentModelCodegenProperties = parentCodegenModel.vars;
         List<CodegenProperty> codegenProperties = codegenModel.vars;
-        codegenModel.allVars = new ArrayList<CodegenProperty>(codegenProperties);
+        codegenModel.allVars = new ArrayList<>(codegenProperties);
         codegenModel.parentVars = parentCodegenModel.allVars;
 
         // Iterate over all of the parent model properties
@@ -984,7 +984,7 @@ public class Swift4Codegen extends DefaultCodegen implements CodegenConfig {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> objectMap = (Map<String, Object>) objs.get("operations");
 
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
             CodegenModel m = (CodegenModel) h.get("model");
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java
index df038dad83289363e21a7b5c65dcc819d570c4f8..5211c1689f6849dcd0617220a3188d5f187337c9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java
@@ -323,7 +323,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
         // Get the properties for the parent and child models
         final List<CodegenProperty> parentModelCodegenProperties = parentCodegenModel.vars;
         List<CodegenProperty> codegenProperties = codegenModel.vars;
-        codegenModel.allVars = new ArrayList<CodegenProperty>(codegenProperties);
+        codegenModel.allVars = new ArrayList<>(codegenProperties);
         codegenModel.parentVars = parentCodegenModel.allVars;
 
         // Iterate over all of the parent model properties
@@ -1136,7 +1136,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> objectMap = (Map<String, Object>) objs.get("operations");
 
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
             CodegenModel m = (CodegenModel) h.get("model");
@@ -1146,7 +1146,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
         List<CodegenOperation> operations = (List<CodegenOperation>) objectMap.get("operation");
         for (CodegenOperation operation : operations) {
             for (CodegenParameter cp : operation.allParams) {
-                cp.vendorExtensions.put("x-swift-example", constructExampleCode(cp, modelMaps, new HashSet<String>()));
+                cp.vendorExtensions.put("x-swift-example", constructExampleCode(cp, modelMaps, new HashSet<>()));
             }
         }
         return objs;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java
index a00b28395f697a06c286b2e94723dcbab64db1e3..f59732e5920d0c360147dcc801e1922ba83a84b0 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java
@@ -569,7 +569,7 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
      * Parse imports
      */
     private Set<String> parseImports(CodegenModel cm) {
-        Set<String> newImports = new HashSet<String>();
+        Set<String> newImports = new HashSet<>();
         if (cm.imports.size() > 0) {
             for (String name : cm.imports) {
                 if (name.indexOf(" | ") >= 0) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
index b7233be4cb69f06d7f2305652d821c2e564dc7e1..80ccc3cf2a79007266833eab6611a343ac3f03cb 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
@@ -146,13 +146,13 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
                 "Map"
         ));
 
-        languageGenericTypes = new HashSet<String>(Arrays.asList(
+        languageGenericTypes = new HashSet<>(Arrays.asList(
                 "Array"
         ));
 
         instantiationTypes.put("array", "Array");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("Array", "Array");
         typeMapping.put("array", "Array");
         typeMapping.put("List", "Array");
@@ -339,7 +339,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
      * @return TypeScript return type
      */
     private String getReturnType(List<CodegenResponse> responses) {
-        Set<String> returnTypes = new HashSet<String>();
+        Set<String> returnTypes = new HashSet<>();
         for (CodegenResponse response: responses) {
             if (response.is2xx) {
                 if (response.dataType != null) {
@@ -424,7 +424,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
     }
 
     protected String toTypescriptTypeName(final String name, String safePrefix) {
-        ArrayList<String> exceptions = new ArrayList<String>(Arrays.asList("\\|", " "));
+        ArrayList<String> exceptions = new ArrayList<>(Arrays.asList("\\|", " "));
         String sanName = sanitizeName(name, "(?![| ])\\W", exceptions);
 
         sanName = camelize(sanName);
@@ -481,12 +481,12 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
         } else if (ModelUtils.isIntegerSchema(p)) {
             // Handle integer enums
             if (p.getEnum() != null) {
-                return numericEnumValuesToEnumTypeUnion(new ArrayList<Number>(p.getEnum()));
+                return numericEnumValuesToEnumTypeUnion(new ArrayList<>(p.getEnum()));
             }
         } else if (ModelUtils.isNumberSchema(p)) {
             // Handle double enums
             if (p.getEnum() != null) {
-                return numericEnumValuesToEnumTypeUnion(new ArrayList<Number>(p.getEnum()));
+                return numericEnumValuesToEnumTypeUnion(new ArrayList<>(p.getEnum()));
             }
         }
         return this.getTypeDeclaration(p);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
index ed92221901686f568651d5f463714953ad00bd0c..f970dccb1d5aabfdded492eb2b99f0a10c56addb 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
@@ -331,8 +331,8 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
 
     @Override
     public Map<String, Object> postProcessAllModels(Map<String, Object> objs) {
-        List<ExtendedCodegenModel> allModels = new ArrayList<ExtendedCodegenModel>();
-        List<String> entityModelClassnames = new ArrayList<String>();
+        List<ExtendedCodegenModel> allModels = new ArrayList<>();
+        List<String> entityModelClassnames = new ArrayList<>();
 
         Map<String, Object> result = super.postProcessAllModels(objs);
         for (Map.Entry<String, Object> entry : result.entrySet()) {
@@ -413,7 +413,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
     @Override
     public List<CodegenParameter> fromRequestBodyToFormParameters(RequestBody body, Set<String> imports) {
         List<CodegenParameter> superParams = super.fromRequestBodyToFormParameters(body, imports);
-        List<CodegenParameter> extendedParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> extendedParams = new ArrayList<>();
         for (CodegenParameter cp : superParams) {
             extendedParams.add(new ExtendedCodegenParameter(cp));
         }
@@ -751,8 +751,8 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
         // The api template uses this information to import all the required
         // models for a given operation.
         List<Map<String, Object>> imports = (List<Map<String, Object>>) operations.get("imports");
-        List<String> existingRecordClassNames = new ArrayList<String>();
-        List<String> existingClassNames = new ArrayList<String>();
+        List<String> existingRecordClassNames = new ArrayList<>();
+        List<String> existingClassNames = new ArrayList<>();
         for (Map<String, Object> im : imports) {
             String className = im.get("import").toString().replace(modelPackage() + ".", "");
             existingClassNames.add(className);
@@ -763,7 +763,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
         if (this.getSagasAndRecords()) {
             Map<String, Object> _operations = (Map<String, Object>) operations.get("operations");
             List<ExtendedCodegenOperation> operationList = (List<ExtendedCodegenOperation>) _operations.get("operation");
-            Set<String> additionalPassthroughImports = new TreeSet<String>();
+            Set<String> additionalPassthroughImports = new TreeSet<>();
             for (ExtendedCodegenOperation op : operationList) {
                 if (op.returnPassthrough != null && op.returnBaseTypeAlternate instanceof String) {
                     if (op.returnTypeSupportsEntities && !existingRecordClassNames.contains(op.returnBaseTypeAlternate)) {
@@ -1269,7 +1269,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
     }
 
     class ExtendedCodegenModel extends CodegenModel {
-        public Set<String> modelImports = new TreeSet<String>();
+        public Set<String> modelImports = new TreeSet<>();
         public boolean isEntity; // Is a model containing an "id" property marked as isUniqueId
         public String returnPassthrough;
         public boolean hasReturnPassthroughVoid;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsClientCodegen.java
index 771e66db0a445960022831a5ac631201eb1890d0..bce01279424f4a69c88f8bf982f94d429c5bb7e1 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsClientCodegen.java
@@ -387,7 +387,7 @@ public class TypeScriptNestjsClientCodegen extends AbstractTypeScriptClientCodeg
      * Parse imports
      */
     private Set<String> parseImports(CodegenModel cm) {
-        Set<String> newImports = new HashSet<String>();
+        Set<String> newImports = new HashSet<>();
         if (cm.imports.size() > 0) {
             for (String name : cm.imports) {
                 if (name.indexOf(" | ") >= 0) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptRxjsClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptRxjsClientCodegen.java
index 9a15de44bd7e8a63e683f03557a28385c310d25c..f3df6e140bdfccb3c81b37957b60331d668ef88a 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptRxjsClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptRxjsClientCodegen.java
@@ -201,7 +201,7 @@ public class TypeScriptRxjsClientCodegen extends AbstractTypeScriptClientCodegen
         // Convert List of CodegenOperation to List of ExtendedCodegenOperation
         Map<String, Object> _operations = (Map<String, Object>) operations.get("operations");
         List<CodegenOperation> os = (List<CodegenOperation>) _operations.get("operation");
-        List<ExtendedCodegenOperation> newOs = new ArrayList<ExtendedCodegenOperation>();
+        List<ExtendedCodegenOperation> newOs = new ArrayList<>();
         for (CodegenOperation o : os) {
             newOs.add(new ExtendedCodegenOperation(o));
         }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/WsdlSchemaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/WsdlSchemaCodegen.java
index ac29e7caba7717902b3a0a893b20b4976c16545b..5c6ffe87ecb6f38bf8b17cf56a3d848d719872b9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/WsdlSchemaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/WsdlSchemaCodegen.java
@@ -219,7 +219,7 @@ public class WsdlSchemaCodegen extends DefaultCodegen implements CodegenConfig {
                     String schemaNamesString =
                             var.items.dataType.substring(6, var.items.dataType.length() - 1);
                     List<String> oneofSchemas =
-                            new ArrayList<String>(Arrays.asList(schemaNamesString.split("\\s*,\\s*")));
+                            new ArrayList<>(Arrays.asList(schemaNamesString.split("\\s*,\\s*")));
 
                     for (int i = 0; i < oneofSchemas.size(); i++) {
                         oneofSchemas.set(i, lowerCaseStringExceptFirstLetter(oneofSchemas.get(i)));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/JsonCacheImpl.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/JsonCacheImpl.java
index cb02519d5079217266bfa03db65e0f7ce48ad2b9..e1084307166a58d68f56df15490b3cbeaa9b2181 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/JsonCacheImpl.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/JsonCacheImpl.java
@@ -1408,7 +1408,7 @@ class JsonCacheImpl implements JsonCache.Root {
             switch (node.getNodeType()) {
                 case ARRAY:
                 case OBJECT:
-                    result = new ArrayList<T>(node.size());
+                    result = new ArrayList<>(node.size());
                     Iterator<JsonNode> elements = node.elements();
                     while (elements.hasNext())
                         result.add(mapper.convertValue(elements.next(), type));
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
index e26bbcaa4583bab03688c4cf5c6e771589f5c696..6d5fced384c9994d3d7ba745d1ff2fa90f5a16c4 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
@@ -132,7 +132,7 @@ public class ModelUtils {
      */
     public static List<String> getAllUsedSchemas(OpenAPI openAPI) {
         Map<String, List<String>> childrenMap = getChildrenMap(openAPI);
-        List<String> allUsedSchemas = new ArrayList<String>();
+        List<String> allUsedSchemas = new ArrayList<>();
         visitOpenAPI(openAPI, (s, t) -> {
             if (s.get$ref() != null) {
                 String ref = getSimpleRef(s.get$ref());
@@ -170,7 +170,7 @@ public class ModelUtils {
         }
 
         childrenMap = tmpChildrenMap;
-        List<String> unusedSchemas = new ArrayList<String>();
+        List<String> unusedSchemas = new ArrayList<>();
 
         if (openAPI != null) {
             Map<String, Schema> schemas = getSchemas(openAPI);
@@ -196,8 +196,8 @@ public class ModelUtils {
      * @return schemas a list of schemas
      */
     public static List<String> getSchemasUsedOnlyInFormParam(OpenAPI openAPI) {
-        List<String> schemasUsedInFormParam = new ArrayList<String>();
-        List<String> schemasUsedInOtherCases = new ArrayList<String>();
+        List<String> schemasUsedInFormParam = new ArrayList<>();
+        List<String> schemasUsedInOtherCases = new ArrayList<>();
 
         visitOpenAPI(openAPI, (s, t) -> {
             if (s.get$ref() != null) {
@@ -884,8 +884,8 @@ public class ModelUtils {
      * @return a list of schemas
      */
     public static List<Schema> getAllSchemas(OpenAPI openAPI) {
-        List<Schema> allSchemas = new ArrayList<Schema>();
-        List<String> refSchemas = new ArrayList<String>();
+        List<Schema> allSchemas = new ArrayList<>();
+        List<String> refSchemas = new ArrayList<>();
         getSchemas(openAPI).forEach((key, schema) -> {
             // Invoke visitSchema to recursively visit all schema objects, included inlined and composed schemas.
             // Use the OpenAPISchemaVisitor visitor function
@@ -1352,7 +1352,7 @@ public class ModelUtils {
      */
     public static List<String> getAllParentsName(ComposedSchema composedSchema, Map<String, Schema> allSchemas, boolean includeAncestors) {
         List<Schema> interfaces = getInterfaces(composedSchema);
-        List<String> names = new ArrayList<String>();
+        List<String> names = new ArrayList<>();
 
         if (interfaces != null && !interfaces.isEmpty()) {
             for (Schema schema : interfaces) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OneOfImplementorAdditionalData.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OneOfImplementorAdditionalData.java
index 47a43e04bdaa01aa0c23d8108acdc27d01d9db74..9ff0fd194ebdd1ab388308717c00c45749d3fd50 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OneOfImplementorAdditionalData.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OneOfImplementorAdditionalData.java
@@ -43,9 +43,9 @@ import java.util.Map;
  */
 public class OneOfImplementorAdditionalData {
     private String implementorName;
-    private List<String> additionalInterfaces = new ArrayList<String>();
-    private List<CodegenProperty> additionalProps = new ArrayList<CodegenProperty>();
-    private List<Map<String, String>> additionalImports = new ArrayList<Map<String, String>>();
+    private List<String> additionalInterfaces = new ArrayList<>();
+    private List<CodegenProperty> additionalProps = new ArrayList<>();
+    private List<Map<String, String>> additionalImports = new ArrayList<>();
     private final Logger LOGGER = LoggerFactory.getLogger(OneOfImplementorAdditionalData.class);
 
     public OneOfImplementorAdditionalData(String implementorName) {
@@ -69,10 +69,10 @@ public class OneOfImplementorAdditionalData {
         // Add all vars defined on cm
         // a "oneOf" model (cm) by default inherits all properties from its "interfaceModels",
         // but we only want to add properties defined on cm itself
-        List<CodegenProperty> toAdd = new ArrayList<CodegenProperty>(cm.vars);
+        List<CodegenProperty> toAdd = new ArrayList<>(cm.vars);
         // note that we can't just toAdd.removeAll(m.vars) for every interfaceModel,
         // as they might have different value of `hasMore` and thus are not equal
-        List<String> omitAdding = new ArrayList<String>();
+        List<String> omitAdding = new ArrayList<>();
         if (cm.interfaceModels != null) {
             for (CodegenModel m : cm.interfaceModels) {
                 for (CodegenProperty v : m.vars) {
@@ -89,7 +89,7 @@ public class OneOfImplementorAdditionalData {
         // Add all imports of cm
         for (Map<String, String> importMap : modelsImports) {
             // we're ok with shallow clone here, because imports are strings only
-            additionalImports.add(new HashMap<String, String>(importMap));
+            additionalImports.add(new HashMap<>(importMap));
         }
     }
 
@@ -103,7 +103,7 @@ public class OneOfImplementorAdditionalData {
      */
     @SuppressWarnings("unchecked")
     public void addToImplementor(CodegenConfig cc, CodegenModel implcm, List<Map<String, String>> implImports, boolean addInterfaceImports) {
-        implcm.getVendorExtensions().putIfAbsent("x-implements", new ArrayList<String>());
+        implcm.getVendorExtensions().putIfAbsent("x-implements", new ArrayList<>());
 
         // Add implemented interfaces
         for (String intf : additionalInterfaces) {
@@ -112,7 +112,7 @@ public class OneOfImplementorAdditionalData {
             if (addInterfaceImports) {
                 // Add imports for interfaces
                 implcm.imports.add(intf);
-                Map<String, String> importsItem = new HashMap<String, String>();
+                Map<String, String> importsItem = new HashMap<>();
                 importsItem.put("import", cc.toModelImport(intf));
                 implImports.add(importsItem);
             }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OptionUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OptionUtils.java
index ee25cdadea1e8daf6a662259cb5199090ad7fcdd..4197501bbb1228a97503fefd3cfe9dffade51e1f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OptionUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OptionUtils.java
@@ -28,7 +28,7 @@ public class OptionUtils {
 
     public static List<Pair<String, String>> parseCommaSeparatedTuples(final String input) {
 
-        final List<Pair<String, String>> results = new ArrayList<Pair<String, String>>();
+        final List<Pair<String, String>> results = new ArrayList<>();
 
         final List<String> tuples = splitCommaSeparatedList(input);
 
@@ -48,7 +48,7 @@ public class OptionUtils {
 
     public static List<String> splitCommaSeparatedList(String input) {
 
-        List<String> results = new ArrayList<String>();
+        List<String> results = new ArrayList<>();
 
         if(input != null && !input.isEmpty()) {
             for (String value : input.split(",")) {
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/validations/oas/OpenApiSchemaValidations.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/validations/oas/OpenApiSchemaValidations.java
index af784363e2971471bdbdb3072f77db19d02444ef..4e9ec0ef93d98c3f0b6b821fdc1101b6daad4ee6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/validations/oas/OpenApiSchemaValidations.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/validations/oas/OpenApiSchemaValidations.java
@@ -148,7 +148,7 @@ class OpenApiSchemaValidations extends GenericValidator<SchemaWrapper> {
     }
 
     // The set of valid OAS values for the 'type' attribute.
-    private static Set<String> validTypes = new HashSet<String>(
+    private static Set<String> validTypes = new HashSet<>(
         Arrays.asList("null", "boolean", "object", "array", "number", "string", "integer"));
 
     /**
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/AbstractOptionsTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/AbstractOptionsTest.java
index 4e3b98f69a288f3b6bc179bf8c2461523816d64b..58128c768f04dc9ebe638a183b86af1f11b4a66a 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/AbstractOptionsTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/AbstractOptionsTest.java
@@ -56,12 +56,12 @@ public abstract class AbstractOptionsTest {
     public void checkOptionsHelp() {
         final List<String> cliOptions = getCodegenConfig().cliOptions().stream().map(getCliOptionTransformer()).collect(Collectors.toList());
         final Set<String> testOptions = optionsProvider.createOptions().keySet();
-        final Set<String> skipped = new HashSet<String>(cliOptions);
+        final Set<String> skipped = new HashSet<>(cliOptions);
         skipped.removeAll(testOptions);
         if (!skipped.isEmpty()) {
             Assert.fail(String.format(Locale.ROOT, "These options weren't checked: %s.", StringUtils.join(skipped, ", ")));
         }
-        final Set<String> undocumented = new HashSet<String>(testOptions);
+        final Set<String> undocumented = new HashSet<>(testOptions);
         undocumented.removeAll(cliOptions);
         if (!undocumented.isEmpty()) {
             Assert.fail(String.format(Locale.ROOT,"These options weren't documented: %s. Are you expecting base options and calling cliOptions.clear()?", StringUtils.join(undocumented, ", ")));
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
index 83917da4eba7f92817170b9ec560b113610c6cc9..5e2da168c28d17e6fcb87fc46536d3c06d52cd00 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
@@ -219,7 +219,7 @@ public class DefaultCodegenTest {
         codegen.setOpenAPI(openAPI);
 
         Schema requestBodySchema = ModelUtils.getSchemaFromRequestBody(openAPI.getPaths().get("/fake").getGet().getRequestBody());
-        CodegenParameter codegenParameter = codegen.fromFormProperty("enum_form_string", (Schema) requestBodySchema.getProperties().get("enum_form_string"), new HashSet<String>());
+        CodegenParameter codegenParameter = codegen.fromFormProperty("enum_form_string", (Schema) requestBodySchema.getProperties().get("enum_form_string"), new HashSet<>());
 
         Assert.assertEquals(codegenParameter.defaultValue, "-efg");
     }
@@ -601,7 +601,7 @@ public class DefaultCodegenTest {
         codegen.setOpenAPI(openAPI);
         CodegenModel fruit = codegen.fromModel("Fruit", schema);
 
-        Set<String> oneOf = new TreeSet<String>();
+        Set<String> oneOf = new TreeSet<>();
         oneOf.add("Apple");
         oneOf.add("Banana");
         Assert.assertEquals(fruit.oneOf, oneOf);
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/asciidoc/AsciidocGeneratorTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/asciidoc/AsciidocGeneratorTest.java
index c5f01e4b74d8ad8c8fbe2803ece2e1bf53c45f45..12a51e2bec3811ff3c871baf3ff1b14f7d0babd4 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/asciidoc/AsciidocGeneratorTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/asciidoc/AsciidocGeneratorTest.java
@@ -87,7 +87,7 @@ public class AsciidocGeneratorTest {
 
         LOGGER.info("test: generating sample markup {}", output.getAbsolutePath());
 
-        Map<String, Object> props = new TreeMap<String, Object>();
+        Map<String, Object> props = new TreeMap<>();
         props.put("specDir", "spec");
 
         final CodegenConfigurator configurator = new CodegenConfigurator().setGeneratorName("asciidoc")
@@ -119,7 +119,7 @@ public class AsciidocGeneratorTest {
 
         LOGGER.info("test: generating sample markup {}", output.getAbsolutePath());
 
-        Map<String, Object> props = new TreeMap<String, Object>();
+        Map<String, Object> props = new TreeMap<>();
         props.put("specDir", "spec");
 
         final CodegenConfigurator configurator = new CodegenConfigurator()
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharp/CsharpModelEnumTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharp/CsharpModelEnumTest.java
index aacdece2e4cb195c434a50c8aca03648d267be3c..0c4c722d2b82458f97b7a09b0aae9b36099f90e3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharp/CsharpModelEnumTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharp/CsharpModelEnumTest.java
@@ -45,11 +45,11 @@ public class CsharpModelEnumTest {
         subEnumProperty.setEnum(Arrays.asList("SUB1", "SUB2", "SUB3"));
 
         // Add one enum property to the parent
-        final Map<String, Schema> parentProperties = new HashMap<String, Schema>();
+        final Map<String, Schema> parentProperties = new HashMap<>();
         parentProperties.put("sharedThing", identicalEnumProperty);
 
         // Add TWO enums to the subType model; one of which is identical to the one in parent class
-        final Map<String, Schema> subProperties = new HashMap<String, Schema>();
+        final Map<String, Schema> subProperties = new HashMap<>();
         subProperties.put("sharedThing", identicalEnumProperty);
         subProperties.put("unsharedThing", identicalEnumProperty);
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/DartClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/DartClientCodegenTest.java
index a49ee4e825cc2661ff4923498b7fc0ddf5d131ab..23de2dc6c7a474991ea9ad0cff361050239553b9 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/DartClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/DartClientCodegenTest.java
@@ -65,7 +65,7 @@ public class DartClientCodegenTest {
     public void testKeywords() throws Exception {
         final DartClientCodegen codegen = new DartClientCodegen();
 
-        List<String> reservedWordsList = new ArrayList<String>();
+        List<String> reservedWordsList = new ArrayList<>();
         try {
             BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("src/main/resources/dart/dart-keywords.txt"), Charset.forName("UTF-8")));
             while(reader.ready()) {
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
index 95a47ba87fe9687b51da359ac5bab5c3bb08e845..ac6eb7caab807440ca0ad7825944ed28a67fe0ca 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
@@ -64,7 +64,7 @@ public class DartDioClientCodegenTest {
     public void testKeywords() throws Exception {
         final DartDioClientCodegen codegen = new DartDioClientCodegen();
 
-        List<String> reservedWordsList = new ArrayList<String>();
+        List<String> reservedWordsList = new ArrayList<>();
         try {
             BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("src/main/resources/dart/dart-keywords.txt"), Charset.forName("UTF-8")));
             while(reader.ready()) { reservedWordsList.add(reader.readLine()); }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioNextClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioNextClientCodegenTest.java
index 898e32810b3c188420f393915694b6314a0d068d..697a21cc94d08726f60eec84a6378df4bf8aa03b 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioNextClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioNextClientCodegenTest.java
@@ -65,7 +65,7 @@ public class DartDioNextClientCodegenTest {
     public void testKeywords() throws Exception {
         final DartDioClientCodegen codegen = new DartDioClientCodegen();
 
-        List<String> reservedWordsList = new ArrayList<String>();
+        List<String> reservedWordsList = new ArrayList<>();
         try {
             BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("src/main/resources/dart/dart-keywords.txt"), Charset.forName("UTF-8")));
             while(reader.ready()) { reservedWordsList.add(reader.readLine()); }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/fsharp/FSharpServerCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/fsharp/FSharpServerCodegenTest.java
index fb822ec2df88413d9a1bf6554d4118b85856b750..d3c5951f4189da31211cf39638622d244276a596 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/fsharp/FSharpServerCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/fsharp/FSharpServerCodegenTest.java
@@ -35,26 +35,26 @@ public class FSharpServerCodegenTest {
         final AbstractFSharpCodegen codegen = new P_AbstractFSharpCodegen();
 
         final CodegenModel wheel = new CodegenModel();
-        wheel.setImports(new HashSet<String>(Arrays.asList()));
+        wheel.setImports(new HashSet<>(Arrays.asList()));
         wheel.setClassname("wheel");
 
         final CodegenModel bike = new CodegenModel();
-        bike.setImports(new HashSet<String>(Arrays.asList("wheel")));
+        bike.setImports(new HashSet<>(Arrays.asList("wheel")));
         bike.setClassname("bike");
 
         final CodegenModel parent = new CodegenModel();
-        parent.setImports(new HashSet<String>(Arrays.asList("bike", "car")));
+        parent.setImports(new HashSet<>(Arrays.asList("bike", "car")));
         parent.setClassname("parent");
 
         final CodegenModel car = new CodegenModel();
-        car.setImports(new HashSet<String>(Arrays.asList("wheel")));
+        car.setImports(new HashSet<>(Arrays.asList("wheel")));
         car.setClassname("car");
 
         final CodegenModel child = new CodegenModel();
-        child.setImports(new HashSet<String>(Arrays.asList("car", "bike", "parent")));
+        child.setImports(new HashSet<>(Arrays.asList("car", "bike", "parent")));
         child.setClassname("child");
 
-        Map<String, Object> models = new HashMap<String,Object>();
+        Map<String, Object> models = new HashMap<>();
         models.put("parent", Collections.singletonMap("models", Collections.singletonList(Collections.singletonMap("model", parent))));
         models.put("child", Collections.singletonMap("models", Collections.singletonList(Collections.singletonMap("model", child))));
         models.put("car", Collections.singletonMap("models", Collections.singletonList(Collections.singletonMap("model", car))));
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/haskellyesod/HaskellYesodServerCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/haskellyesod/HaskellYesodServerCodegenTest.java
index 830c159f08d5766b4e3fa3f0de2327aa120d5780..19f143701abd7b6f27ad9092f1fc3088ad15142f 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/haskellyesod/HaskellYesodServerCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/haskellyesod/HaskellYesodServerCodegenTest.java
@@ -51,9 +51,9 @@ public class HaskellYesodServerCodegenTest {
     }
 
     private List<Map<String, Object>> toRoutes(String... paths) {
-        List<Map<String, Object>> routes = new ArrayList<Map<String, Object>>();
+        List<Map<String, Object>> routes = new ArrayList<>();
         for (String path : paths) {
-            Map<String, Object> route = new HashMap<String, Object>();
+            Map<String, Object> route = new HashMap<>();
             route.put("path", path);
             routes.add(route);
         }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
index 21950902f8742d5065c174a829c5b5238cfd2702..4823761e016e01cbda01de6dc9bb6a511807d2b3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
@@ -213,7 +213,7 @@ public class AbstractJavaCodegenTest {
         codegen.processOpts();
         codegen.preprocessOpenAPI(openAPI);
 
-        final List<String> additionalModelTypeAnnotations = new ArrayList<String>();
+        final List<String> additionalModelTypeAnnotations = new ArrayList<>();
         additionalModelTypeAnnotations.add("@Foo");
         additionalModelTypeAnnotations.add("@Bar");
 
@@ -235,7 +235,7 @@ public class AbstractJavaCodegenTest {
         codegen.processOpts();
         codegen.preprocessOpenAPI(openAPI);
 
-        final List<String> additionalModelTypeAnnotations = new ArrayList<String>();
+        final List<String> additionalModelTypeAnnotations = new ArrayList<>();
         additionalModelTypeAnnotations.add("@Foo");
         additionalModelTypeAnnotations.add("@Bar");
 
@@ -257,7 +257,7 @@ public class AbstractJavaCodegenTest {
         codegen.processOpts();
         codegen.preprocessOpenAPI(openAPI);
 
-        final List<String> additionalModelTypeAnnotations = new ArrayList<String>();
+        final List<String> additionalModelTypeAnnotations = new ArrayList<>();
         additionalModelTypeAnnotations.add("@Foo");
         additionalModelTypeAnnotations.add("@Bar");
 
@@ -279,7 +279,7 @@ public class AbstractJavaCodegenTest {
         codegen.processOpts();
         codegen.preprocessOpenAPI(openAPI);
         
-        final List<String> additionalModelTypeAnnotations = new ArrayList<String>();
+        final List<String> additionalModelTypeAnnotations = new ArrayList<>();
         additionalModelTypeAnnotations.add("@Foo");
         additionalModelTypeAnnotations.add("@Bar");
         additionalModelTypeAnnotations.add("@Foobar");
@@ -302,7 +302,7 @@ public class AbstractJavaCodegenTest {
         codegen.processOpts();
         codegen.preprocessOpenAPI(openAPI);
         
-        final List<String> additionalModelTypeAnnotations = new ArrayList<String>();
+        final List<String> additionalModelTypeAnnotations = new ArrayList<>();
         additionalModelTypeAnnotations.add("@Foo");
         additionalModelTypeAnnotations.add("@Bar");
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
index c9d4090b050a64e61376cde8ff597bf4374d4e5f..5477794e7640390e978ec7e2e2911be8770d4cb3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
@@ -84,7 +84,7 @@ public class JavaClientCodegenTest {
         RequestBody body1 = new RequestBody();
         body1.setDescription("A list of ids");
         body1.setContent(new Content().addMediaType("application/json", new MediaType().schema(new ArraySchema().items(new StringSchema()))));
-        CodegenParameter codegenParameter1 = codegen.fromRequestBody(body1, new HashSet<String>(), null);
+        CodegenParameter codegenParameter1 = codegen.fromRequestBody(body1, new HashSet<>(), null);
         Assert.assertEquals(codegenParameter1.description, "A list of ids");
         Assert.assertEquals(codegenParameter1.dataType, "List<String>");
         Assert.assertEquals(codegenParameter1.baseType, "String");
@@ -92,7 +92,7 @@ public class JavaClientCodegenTest {
         RequestBody body2 = new RequestBody();
         body2.setDescription("A list of list of values");
         body2.setContent(new Content().addMediaType("application/json", new MediaType().schema(new ArraySchema().items(new ArraySchema().items(new IntegerSchema())))));
-        CodegenParameter codegenParameter2 = codegen.fromRequestBody(body2, new HashSet<String>(), null);
+        CodegenParameter codegenParameter2 = codegen.fromRequestBody(body2, new HashSet<>(), null);
         Assert.assertEquals(codegenParameter2.description, "A list of list of values");
         Assert.assertEquals(codegenParameter2.dataType, "List<List<Integer>>");
         Assert.assertEquals(codegenParameter2.baseType, "List");
@@ -104,7 +104,7 @@ public class JavaClientCodegenTest {
         point.addProperties("message", new StringSchema());
         point.addProperties("x", new IntegerSchema().format(SchemaTypeUtil.INTEGER32_FORMAT));
         point.addProperties("y", new IntegerSchema().format(SchemaTypeUtil.INTEGER32_FORMAT));
-        CodegenParameter codegenParameter3 = codegen.fromRequestBody(body3, new HashSet<String>(), null);
+        CodegenParameter codegenParameter3 = codegen.fromRequestBody(body3, new HashSet<>(), null);
         Assert.assertEquals(codegenParameter3.description, "A list of points");
         Assert.assertEquals(codegenParameter3.dataType, "List<Point>");
         Assert.assertEquals(codegenParameter3.baseType, "Point");
@@ -133,7 +133,7 @@ public class JavaClientCodegenTest {
         codegenOperation.allParams = Arrays.asList(queryParamRequired, pathParam1, pathParam2, queryParamOptional);
         Map<String, Object> operations = ImmutableMap.<String, Object>of("operation", Arrays.asList(codegenOperation));
 
-        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<Map<String, String>>());
+        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<>());
 
         javaClientCodegen.postProcessOperationsWithModels(objs, Collections.emptyList());
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ktorm/KtormSchemaCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ktorm/KtormSchemaCodegenTest.java
index f8285da45c329edc0b525586d40f3856c121864c..bd7e8eb320cc75260271f3ef086bc7352f5988e1 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ktorm/KtormSchemaCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ktorm/KtormSchemaCodegenTest.java
@@ -35,8 +35,8 @@ import java.util.Map;
 public class KtormSchemaCodegenTest {
 
     private Map<String, Object> toObjs(CodegenModel cm) {
-        Map<String, Object> objs = new HashMap<String, Object>();
-        List<Object> models = new ArrayList<Object>();
+        Map<String, Object> objs = new HashMap<>();
+        List<Object> models = new ArrayList<>();
         Map<String, Object> model = new HashMap<>();
         model.put("model", cm);
         models.add(model);
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/BashClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/BashClientOptionsProvider.java
index b2c8415fdca0394af00d8ea4c62e0d8e9d73e5d6..8d9f2b56ebfad31ef84118690e0e81f76bd74ef3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/BashClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/BashClientOptionsProvider.java
@@ -49,7 +49,7 @@ public class BashClientOptionsProvider implements OptionsProvider {
     public Map<String, String> createOptions() {
 
         ImmutableMap.Builder<String, String> builder
-            = new ImmutableMap.Builder<String, String>();
+            = new ImmutableMap.Builder<>();
 
         return builder
                 .put(BashClientCodegen.CURL_OPTIONS, CURL_OPTIONS)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartClientOptionsProvider.java
index 464560449f0140f2e734721a07542172babc22ed..f86592bf2c63731e7456c5846c47bf799b8edc81 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartClientOptionsProvider.java
@@ -47,7 +47,7 @@ public class DartClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioClientOptionsProvider.java
index fa6bb3eeadb140de7b3c8a476f960f04551339a0..ec2fd05a86df74c943282b62c278579146597150 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioClientOptionsProvider.java
@@ -49,7 +49,7 @@ public class DartDioClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioNextClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioNextClientOptionsProvider.java
index 2b4840d7d42c6dadbc3c1811460958e604484b52..8e53df17f167a9bf4cebb4c087db4938b096cf36 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioNextClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/DartDioNextClientOptionsProvider.java
@@ -45,7 +45,7 @@ public class DartDioNextClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ElixirClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ElixirClientOptionsProvider.java
index bd39161584fd0a5a7c4b493f0c6da0b08216843a..78001a1e4424b948009891e21edf05fbc2fa5a6a 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ElixirClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ElixirClientOptionsProvider.java
@@ -33,7 +33,7 @@ public class ElixirClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, "false")
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, "false")
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoClientOptionsProvider.java
index 3ac5e44cf9ac02d1734379e43fbde75aab0dfdb2..e98293b1e3125fa6987a13ed0d406a3fd2f58ef7 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoClientOptionsProvider.java
@@ -42,7 +42,7 @@ public class GoClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder
                 .put(CodegenConstants.PACKAGE_VERSION, PACKAGE_VERSION_VALUE)
                 .put(CodegenConstants.PACKAGE_NAME, PACKAGE_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoGinServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoGinServerOptionsProvider.java
index 910f9441c18f4f9ff1ca01356338c3af275fe397..2a4db6af30ccc44837a46e261f122b02f48e479b 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoGinServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoGinServerOptionsProvider.java
@@ -34,7 +34,7 @@ public class GoGinServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
                 .put(CodegenConstants.ALLOW_UNICODE_IDENTIFIERS, ALLOW_UNICODE_IDENTIFIERS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoServerOptionsProvider.java
index e445afd3fc2ee467d8f26db6b90230ef317bd7ab..0a8c571d0b38cf0f621091902bba3d4f82f00066 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/GoServerOptionsProvider.java
@@ -35,7 +35,7 @@ public class GoServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
                 .put(CodegenConstants.ALLOW_UNICODE_IDENTIFIERS, ALLOW_UNICODE_IDENTIFIERS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellServantOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellServantOptionsProvider.java
index 728b44ef38fe068bdc5197c12eb1132fcdca808d..060d4cf33f21b050472f724400a8e813eaaa90a8 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellServantOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellServantOptionsProvider.java
@@ -39,7 +39,7 @@ public class HaskellServantOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(CodegenConstants.API_PACKAGE, API_PACKAGE_VALUE)
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellYesodServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellYesodServerOptionsProvider.java
index 230c2243a80344178305b1e8fa59dc775a0a4b0f..198d053d9b19c7bc261c61cb36f150e9c60a091d 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellYesodServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/HaskellYesodServerOptionsProvider.java
@@ -22,7 +22,7 @@ public class HaskellYesodServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/MysqlSchemaOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/MysqlSchemaOptionsProvider.java
index ccb40f73a0d97039ee9c31d678fc1391e6b98b5a..c0433a3b6aa181cf840c444873eb060f35143318 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/MysqlSchemaOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/MysqlSchemaOptionsProvider.java
@@ -34,7 +34,7 @@ public class MysqlSchemaOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(MysqlSchemaCodegen.DEFAULT_DATABASE_NAME, DEFAULT_DATABASE_NAME_VALUE)
             .put(MysqlSchemaCodegen.JSON_DATA_TYPE_ENABLED, JSON_DATA_TYPE_ENABLED_VALUE)
             .put(MysqlSchemaCodegen.IDENTIFIER_NAMING_CONVENTION, IDENTIFIER_NAMING_CONVENTION_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/NimClientCodegenOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/NimClientCodegenOptionsProvider.java
index c5e5eb63aa5d79fb225ad8283f92f58c7a100694..183b1010960bc6f6ebb65353757a6c87fd528331 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/NimClientCodegenOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/NimClientCodegenOptionsProvider.java
@@ -16,7 +16,7 @@ public class NimClientCodegenOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder
                 .put(NimClientCodegen.PROJECT_NAME, PROJECT_NAME_VALUE)
                 .build();
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ObjcClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ObjcClientOptionsProvider.java
index 79cd37e66a27daa0aa7cc533f45e52488f624a2d..d8d23d9e4799a18ecdb983cdb16df5f6f5409aaa 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ObjcClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ObjcClientOptionsProvider.java
@@ -39,7 +39,7 @@ public class ObjcClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(ObjcClientCodegen.CLASS_PREFIX, CLASS_PREFIX_VALUE)
                 .put(ObjcClientCodegen.POD_NAME, POD_NAME_VALUE)
                 .put(CodegenConstants.POD_VERSION, POD_VERSION_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PerlClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PerlClientOptionsProvider.java
index 717e92a236cd606879a198d599fb348b479a7cb6..a9d34639865e1b6339d3c12584cb59b4ddebd3f0 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PerlClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PerlClientOptionsProvider.java
@@ -35,7 +35,7 @@ public class PerlClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(PerlClientCodegen.MODULE_NAME, MODULE_NAME_VALUE)
                 .put(PerlClientCodegen.MODULE_VERSION, MODULE_VERSION_VALUE)
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, "true")
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpClientOptionsProvider.java
index b2a987d924ea8fb087b58dc2aeeb6145803d9a51..e0324c3924ae6a2e0138b5d2c6454185e267da3c 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpClientOptionsProvider.java
@@ -44,7 +44,7 @@ public class PhpClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(CodegenConstants.API_PACKAGE, API_PACKAGE_VALUE)
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpLumenServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpLumenServerOptionsProvider.java
index 25d34b16d80a1f92d318e1418f48cfa71bad01c4..5567c0da6579b52b3b5a053a44d95e0c346b06c4 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpLumenServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpLumenServerOptionsProvider.java
@@ -44,7 +44,7 @@ public class PhpLumenServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(AbstractPhpCodegen.VARIABLE_NAMING_CONVENTION, VARIABLE_NAMING_CONVENTION_VALUE)
                 .put(AbstractPhpCodegen.PACKAGE_NAME, PACKAGE_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSilexServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSilexServerOptionsProvider.java
index b6c55c7a27b2a3cf8d6c6e14a0a10a52803e15ac..d624620bf8558e3be070eda5b420f516b1cab580 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSilexServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSilexServerOptionsProvider.java
@@ -36,7 +36,7 @@ public class PhpSilexServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlim4ServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlim4ServerOptionsProvider.java
index 3295ed9510110bb668cf38a6d27e174ec9c8e57a..727e84443ad8b6a1cf782d486ad2c1108c1881e3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlim4ServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlim4ServerOptionsProvider.java
@@ -46,7 +46,7 @@ public class PhpSlim4ServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(AbstractPhpCodegen.VARIABLE_NAMING_CONVENTION, VARIABLE_NAMING_CONVENTION_VALUE)
                 .put(AbstractPhpCodegen.PACKAGE_NAME, PACKAGE_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlimServerOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlimServerOptionsProvider.java
index 4a40588c0ebb07e1f25398c1084bef38ba908d36..da32fd3a672409a78e95b912b8d0b4675559a45d 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlimServerOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PhpSlimServerOptionsProvider.java
@@ -44,7 +44,7 @@ public class PhpSlimServerOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(AbstractPhpCodegen.VARIABLE_NAMING_CONVENTION, VARIABLE_NAMING_CONVENTION_VALUE)
                 .put(AbstractPhpCodegen.PACKAGE_NAME, PACKAGE_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonClientOptionsProvider.java
index fc7d74074dd8b90fce75282d9ce11f64a5a527ac..23df93336bca2454eadd69e9b8cb1c830d0a2e21 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonClientOptionsProvider.java
@@ -40,7 +40,7 @@ public class PythonClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(PythonClientCodegen.PACKAGE_URL, PACKAGE_URL_VALUE)
                 .put(CodegenConstants.PACKAGE_NAME, PACKAGE_NAME_VALUE)
                 .put(CodegenConstants.PROJECT_NAME, PROJECT_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonLegacyClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonLegacyClientOptionsProvider.java
index 90e76caea16f41413e7104c0eaa9f0f2f0da55c1..6ef346c98a0b39c6f115696e5ee95f71cfd7ca6a 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonLegacyClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/PythonLegacyClientOptionsProvider.java
@@ -38,7 +38,7 @@ public class PythonLegacyClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(PythonLegacyClientCodegen.PACKAGE_URL, PACKAGE_URL_VALUE)
                 .put(CodegenConstants.PACKAGE_NAME, PACKAGE_NAME_VALUE)
                 .put(CodegenConstants.PROJECT_NAME, PROJECT_NAME_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/RubyClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/RubyClientOptionsProvider.java
index 9d5c63f9d2dacc0356933aff0e4ee17fd71ed0fe..1f8e36a276ba9700990a8a1c3af1bf4899f4fa32 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/RubyClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/RubyClientOptionsProvider.java
@@ -48,7 +48,7 @@ public class RubyClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.GEM_NAME, GEM_NAME_VALUE)
                 .put(CodegenConstants.MODULE_NAME, MODULE_NAME_VALUE)
                 .put(RubyClientCodegen.GEM_VERSION, GEM_VERSION_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaAkkaClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaAkkaClientOptionsProvider.java
index 62909fb5b3f26c4cd3dabc0b086d4fa18d2801fa..81f1fd9f915e2ba466c91819a7d0813fda07a172 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaAkkaClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaAkkaClientOptionsProvider.java
@@ -43,7 +43,7 @@ public class ScalaAkkaClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(CodegenConstants.API_PACKAGE, API_PACKAGE_VALUE)
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaHttpClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaHttpClientOptionsProvider.java
index ac3c7f713c55e5be79afb179a8790b1a1155de63..d8c8bbf3f5142e858df1052974ac868e81583bd3 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaHttpClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/ScalaHttpClientOptionsProvider.java
@@ -41,7 +41,7 @@ public class ScalaHttpClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.MODEL_PACKAGE, MODEL_PACKAGE_VALUE)
                 .put(CodegenConstants.API_PACKAGE, API_PACKAGE_VALUE)
                 .put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
@@ -61,4 +61,4 @@ public class ScalaHttpClientOptionsProvider implements OptionsProvider {
     public boolean isServer() {
         return false;
     }
-}
\ No newline at end of file
+}
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift4OptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift4OptionsProvider.java
index 038c40121d6238d5cea66a79d6c011ec81fa79b2..68f65912f467db8a0bb23537447fbe4cbd835e30 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift4OptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift4OptionsProvider.java
@@ -56,7 +56,7 @@ public class Swift4OptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift5OptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift5OptionsProvider.java
index cf6b8ba3bfa8bcd09cc219d07376a428ab588e64..9ea72b50507a42126bb1dfd6fbc85f6236351555 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift5OptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/Swift5OptionsProvider.java
@@ -63,7 +63,7 @@ public class Swift5OptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularClientOptionsProvider.java
index aa67286b97868e8d2b8431fd8d6491c1ac700d98..e69009196444b170c2d2b5dcf13c235940571842 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularClientOptionsProvider.java
@@ -58,7 +58,7 @@ public class TypeScriptAngularClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularJsClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularJsClientOptionsProvider.java
index 1b9c8a58e17437f8a9d1ef54d6bf74d598728059..cfdd49d964ff47732736657b9c0c0f8e86c072c5 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularJsClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAngularJsClientOptionsProvider.java
@@ -43,7 +43,7 @@ public class TypeScriptAngularJsClientOptionsProvider implements OptionsProvider
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.SUPPORTS_ES6, SUPPORTS_ES6_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAureliaClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAureliaClientOptionsProvider.java
index 939a0fad979b8bc2e845fa888e2fbb38168caf8c..72da77a56b4b2fdba27c66e1ee499c136a440a2d 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAureliaClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptAureliaClientOptionsProvider.java
@@ -46,7 +46,7 @@ public class TypeScriptAureliaClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptFetchClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptFetchClientOptionsProvider.java
index f33f1c437d64235b89a90ea034f66ede33cef208..f50acec0a1634df130121a02d81a6e4cf6321055 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptFetchClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptFetchClientOptionsProvider.java
@@ -50,7 +50,7 @@ public class TypeScriptFetchClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNestjsClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNestjsClientOptionsProvider.java
index d86f586e15c38e04931c8819d913d92939cde44d..58d263b4207b236cbee8aeb70164b04a53ba7a1f 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNestjsClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNestjsClientOptionsProvider.java
@@ -54,7 +54,7 @@ public class TypeScriptNestjsClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.ENSURE_UNIQUE_PARAMS, ENSURE_UNIQUE_PARAMS_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNodeClientOptionsProvider.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNodeClientOptionsProvider.java
index fb2b6a741dc57d470e57836b038bca0172cdcfc0..4777cdfef897d8e1b03897f052a36f5ac856ca65 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNodeClientOptionsProvider.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptNodeClientOptionsProvider.java
@@ -49,7 +49,7 @@ public class TypeScriptNodeClientOptionsProvider implements OptionsProvider {
 
     @Override
     public Map<String, String> createOptions() {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<String, String>();
+        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
         return builder.put(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG, SORT_PARAMS_VALUE)
                 .put(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG, SORT_MODEL_PROPERTIES_VALUE)
                 .put(CodegenConstants.SUPPORTS_ES6, SUPPORTS_ES6_VALUE)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/php/PhpModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/php/PhpModelTest.java
index db989db8dc150c48db664dfcf1b9deb3b82712d2..8eef24e74fb6646f6d338bffac14f4242a7614d0 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/php/PhpModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/php/PhpModelTest.java
@@ -311,11 +311,11 @@ public class PhpModelTest {
         Assert.assertTrue(prope.isEnum);
         Assert.assertEquals(prope.allowableValues.get("values"), Arrays.asList("fish", "crab"));
 
-        HashMap<String, Object> fish= new HashMap<String, Object>();
+        HashMap<String, Object> fish= new HashMap<>();
         fish.put("name", "FISH");
         fish.put("value", "\'fish\'");
         fish.put("isString", true);
-        HashMap<String, Object> crab= new HashMap<String, Object>();
+        HashMap<String, Object> crab= new HashMap<>();
         crab.put("name", "CRAB");
         crab.put("value", "\'crab\'");
         crab.put("isString", true);
@@ -347,11 +347,11 @@ public class PhpModelTest {
         Assert.assertNull(prope.items);
         Assert.assertEquals(prope.allowableValues.get("values"), Arrays.asList(1, -1));
 
-        HashMap<String, Object> one = new HashMap<String, Object>();
+        HashMap<String, Object> one = new HashMap<>();
         one.put("name", "1");
         one.put("value", "1");
         one.put("isString", false);
-        HashMap<String, Object> minusOne = new HashMap<String, Object>();
+        HashMap<String, Object> minusOne = new HashMap<>();
         minusOne.put("name", "MINUS_1");
         minusOne.put("value", "-1");
         minusOne.put("isString", false);
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
index d82abade09f178c81f2cb1a2555b95392bb5ef1b..e3603504be40e1df6fa92fd57c416f4aa5e9e9e6 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
@@ -164,7 +164,7 @@ public class RubyClientCodegenTest {
         final CodegenOperation op = codegen.fromOperation(path, "post", p, null);
 
         Map<String, Object> operations = ImmutableMap.<String, Object>of("operation", Collections.singletonList(op));
-        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<Map<String, String>>());
+        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<>());
         objs = codegen.postProcessOperationsWithModels(objs, Collections.singletonList(modelMap));
         CodegenOperation postProcessedOp = ((List<CodegenOperation>) ((Map<String, Object>) objs.get("operations")).get("operation")).get(0);
         Assert.assertEquals(postProcessedOp.bodyParams.size(), 1);
@@ -276,13 +276,13 @@ public class RubyClientCodegenTest {
         Assert.assertEquals(cp1.name, "photo_urls");
 
         // test mandatory
-        Set<String> mandatory = new TreeSet<String>();
+        Set<String> mandatory = new TreeSet<>();
         mandatory.add("name");
         mandatory.add("photo_urls");
         Assert.assertEquals(nullablePet.getMandatory(), mandatory);
 
         // test allMandatory
-        Set<String> allMandatory = new TreeSet<String>();
+        Set<String> allMandatory = new TreeSet<>();
         allMandatory.add("name");
         allMandatory.add("photo_urls");
         Assert.assertEquals(nullablePet.getAllMandatory(), allMandatory);
@@ -344,7 +344,7 @@ public class RubyClientCodegenTest {
         codegen.setOpenAPI(openAPI);
         CodegenModel fruit = codegen.fromModel("Fruit", schema);
 
-        Set<String> anyOf = new TreeSet<String>();
+        Set<String> anyOf = new TreeSet<>();
         anyOf.add("Apple");
         anyOf.add("Banana");
         Assert.assertEquals(fruit.anyOf, anyOf);
@@ -360,7 +360,7 @@ public class RubyClientCodegenTest {
         codegen.setOpenAPI(openAPI);
         CodegenModel fruit = codegen.fromModel("Fruit", schema);
 
-        Set<String> oneOf = new TreeSet<String>();
+        Set<String> oneOf = new TreeSet<>();
         oneOf.add("Apple");
         oneOf.add("Banana");
         Assert.assertEquals(fruit.oneOf, oneOf);
@@ -379,7 +379,7 @@ public class RubyClientCodegenTest {
         Assert.assertNotNull(person);
 
         CodegenDiscriminator codegenDiscriminator = person.getDiscriminator();
-        Set<CodegenDiscriminator.MappedModel> mappedModels = new LinkedHashSet<CodegenDiscriminator.MappedModel>();
+        Set<CodegenDiscriminator.MappedModel> mappedModels = new LinkedHashSet<>();
         mappedModels.add(new CodegenDiscriminator.MappedModel("a", "Adult"));
         mappedModels.add(new CodegenDiscriminator.MappedModel("c", "Child"));
         mappedModels.add(new CodegenDiscriminator.MappedModel("Adult", "Adult"));
@@ -400,7 +400,7 @@ public class RubyClientCodegenTest {
         Assert.assertNotNull(person);
 
         CodegenDiscriminator codegenDiscriminator = person.getDiscriminator();
-        Set<CodegenDiscriminator.MappedModel> mappedModels = new LinkedHashSet<CodegenDiscriminator.MappedModel>();
+        Set<CodegenDiscriminator.MappedModel> mappedModels = new LinkedHashSet<>();
         mappedModels.add(new CodegenDiscriminator.MappedModel("a", "Adult"));
         mappedModels.add(new CodegenDiscriminator.MappedModel("c", "Child"));
         Assert.assertEquals(codegenDiscriminator.getMappedModels(), mappedModels);
@@ -628,7 +628,7 @@ public class RubyClientCodegenTest {
         final CodegenOperation op = codegen.fromOperation(path, "delete", p, null);
 
         Map<String, Object> operations = ImmutableMap.<String, Object>of("operation", Collections.singletonList(op));
-        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<Map<String, String>>());
+        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<>());
         objs = codegen.postProcessOperationsWithModels(objs, Collections.emptyList());
         CodegenOperation postProcessedOp = ((List<CodegenOperation>) ((Map<String, Object>) objs.get("operations")).get("operation")).get(0);
 
@@ -648,7 +648,7 @@ public class RubyClientCodegenTest {
         final CodegenOperation op = codegen.fromOperation(path, "delete", p, null);
 
         Map<String, Object> operations = ImmutableMap.<String, Object>of("operation", Collections.singletonList(op));
-        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<Map<String, String>>());
+        Map<String, Object> objs = ImmutableMap.of("operations", operations, "imports", new ArrayList<>());
         objs = codegen.postProcessOperationsWithModels(objs, Collections.emptyList());
         CodegenOperation postProcessedOp = ((List<CodegenOperation>) ((Map<String, Object>) objs.get("operations")).get("operation")).get(0);
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/CamelCaseLambdaTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/CamelCaseLambdaTest.java
index f984adcb0f80cf685fc01eafd798ba43dc238112..22f4a31c95ab7c08e54aed8d10197c2a6ef869e2 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/CamelCaseLambdaTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/CamelCaseLambdaTest.java
@@ -39,7 +39,7 @@ public class CamelCaseLambdaTest extends LambdaTest {
         Map<String, Object> ctx = context("camelcase", new CamelCaseLambda().generator(generator));
 
         when(generator.sanitizeName(anyString())).then(returnsFirstArg());
-        when(generator.reservedWords()).thenReturn(new HashSet<String>(Arrays.asList("reservedWord")));
+        when(generator.reservedWords()).thenReturn(new HashSet<>(Arrays.asList("reservedWord")));
         when(generator.escapeReservedWord("reservedWord")).thenReturn("escapedReservedWord");
 
         // When & Then
@@ -53,7 +53,7 @@ public class CamelCaseLambdaTest extends LambdaTest {
                 .generator(generator).escapeAsParamName(true));
 
         when(generator.sanitizeName(anyString())).then(returnsFirstArg());
-        when(generator.reservedWords()).thenReturn(new HashSet<String>());
+        when(generator.reservedWords()).thenReturn(new HashSet<>());
         when(generator.toParamName("inputText")).thenReturn("inputTextAsParam");
 
         // When & Then
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LambdaTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LambdaTest.java
index fbaed952effba03e0343fd9f2aff664ca70a3368..f7987cdb1ab3503679d654cd28915a73532c52a6 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LambdaTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LambdaTest.java
@@ -34,7 +34,7 @@ public abstract class LambdaTest {
     }
 
     protected static Map<String, Object> context(Object... data) {
-        Map<String, Object> ctx = new HashMap<String, Object>();
+        Map<String, Object> ctx = new HashMap<>();
         for (int ii = 0; ii < data.length; ii += 2) {
             ctx.put(data[ii].toString(), data[ii + 1]);
         }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LowercaseLambdaTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LowercaseLambdaTest.java
index 87ade0caa701a506bf47e2abd2d230b650103a99..4e95b997bcdf5cd636e676ac7f7c8490a332d816 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LowercaseLambdaTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/templating/mustache/LowercaseLambdaTest.java
@@ -39,7 +39,7 @@ public class LowercaseLambdaTest extends LambdaTest {
         Map<String, Object> ctx = context("lowercase", new LowercaseLambda().generator(generator));
 
         when(generator.sanitizeName(anyString())).then(returnsFirstArg());
-        when(generator.reservedWords()).thenReturn(new HashSet<String>(Arrays.asList("reserved")));
+        when(generator.reservedWords()).thenReturn(new HashSet<>(Arrays.asList("reserved")));
         when(generator.escapeReservedWord("reserved")).thenReturn("escaped-reserved");
 
         // When & Then
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
index 8b43b94a8ce976a5ed92159dacc0ee0a7a1b355a..983dbca7577daf61ad1d6cc2602b4c68fde23423 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
@@ -310,11 +310,11 @@ public class TypeScriptFetchModelTest {
         Assert.assertTrue(prope.isEnum);
         Assert.assertEquals(prope.allowableValues.get("values"), Arrays.asList("fish", "crab"));
 
-        HashMap<String, Object> fish = new HashMap<String, Object>();
+        HashMap<String, Object> fish = new HashMap<>();
         fish.put("name", "Fish");
         fish.put("value", "'fish'");
         fish.put("isString", false);
-        HashMap<String, Object> crab = new HashMap<String, Object>();
+        HashMap<String, Object> crab = new HashMap<>();
         crab.put("name", "Crab");
         crab.put("value", "'crab'");
         crab.put("isString", false);
@@ -350,11 +350,11 @@ public class TypeScriptFetchModelTest {
         Assert.assertNull(prope.items);
         Assert.assertEquals(prope.allowableValues.get("values"), Arrays.asList(1, -1));
 
-        HashMap<String, Object> one = new HashMap<String, Object>();
+        HashMap<String, Object> one = new HashMap<>();
         one.put("name", "NUMBER_1");
         one.put("value", "1");
         one.put("isString", false);
-        HashMap<String, Object> minusOne = new HashMap<String, Object>();
+        HashMap<String, Object> minusOne = new HashMap<>();
         minusOne.put("name", "NUMBER_MINUS_1");
         minusOne.put("value", "-1");
         minusOne.put("isString", false);
diff --git a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/ApiInvoker.java b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/ApiInvoker.java
index fd1eba49be83bea9173ab07fe070a0d24ca23747..f0d78827618c1f58da33e7d13bd29f6e264a3810 100644
--- a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/ApiInvoker.java
+++ b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/ApiInvoker.java
@@ -66,7 +66,7 @@ import com.google.gson.JsonParseException;
 
 public class ApiInvoker {
   private static ApiInvoker INSTANCE = new ApiInvoker();
-  private Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private Map<String, String> defaultHeaderMap = new HashMap<>();
 
   private HttpClient client = null;
 
@@ -149,7 +149,7 @@ public class ApiInvoker {
     Format to {@code Pair} objects.
   */
   public static List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -276,7 +276,7 @@ public class ApiInvoker {
     String querystring = b.substring(0, b.length() - 1);
     String url = host + path + querystring;
 
-    HashMap<String, String> headers = new HashMap<String, String>();
+    HashMap<String, String> headers = new HashMap<>();
 
     for(String key : headerParams.keySet()) {
       headers.put(key, headerParams.get(key));
diff --git a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/PetApi.java b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/PetApi.java
index 361994a058f03ca769fbe615be9b6dfad7fe6146..2e9b3e4b223c21088c6995fec6010c3d8d691b56 100644
--- a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/PetApi.java
+++ b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/PetApi.java
@@ -67,11 +67,11 @@ public class PetApi {
     String localVarPath = "/pet".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -120,11 +120,11 @@ public class PetApi {
     String localVarPath = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
     localVarHeaderParams.put("api_key", ApiInvoker.parameterToString(apiKey));
@@ -173,11 +173,11 @@ public class PetApi {
     String localVarPath = "/pet/findByStatus".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
     localVarQueryParams.addAll(ApiInvoker.parameterToPairs("csv", "status", status));
 
@@ -226,11 +226,11 @@ public class PetApi {
     String localVarPath = "/pet/findByTags".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
     localVarQueryParams.addAll(ApiInvoker.parameterToPairs("csv", "tags", tags));
 
@@ -279,11 +279,11 @@ public class PetApi {
     String localVarPath = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -331,11 +331,11 @@ public class PetApi {
     String localVarPath = "/pet".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -385,11 +385,11 @@ public class PetApi {
     String localVarPath = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -449,11 +449,11 @@ localVarFormParams.put("status", ApiInvoker.parameterToString(status));
     String localVarPath = "/pet/{petId}/uploadImage".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/StoreApi.java b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/StoreApi.java
index 17ad5b2c08401b9c63015ea0b664bf3e62d46862..f020f1be1f396cff802b598fd80b3b863826ff0f 100644
--- a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/StoreApi.java
+++ b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/StoreApi.java
@@ -66,11 +66,11 @@ public class StoreApi {
     String localVarPath = "/store/order/{orderId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -113,11 +113,11 @@ public class StoreApi {
     String localVarPath = "/store/inventory".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -165,11 +165,11 @@ public class StoreApi {
     String localVarPath = "/store/order/{orderId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -217,11 +217,11 @@ public class StoreApi {
     String localVarPath = "/store/order".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/UserApi.java b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/UserApi.java
index c6a854dec5798c2e20abdbeff3000f24fa83a7c0..dd982dd5bd9d157ca2d7d4631c7c08d9ea8aaadd 100644
--- a/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/UserApi.java
+++ b/samples/client/petstore/android/httpclient/src/main/java/org/openapitools/client/api/UserApi.java
@@ -66,11 +66,11 @@ public class UserApi {
     String localVarPath = "/user".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -118,11 +118,11 @@ public class UserApi {
     String localVarPath = "/user/createWithArray".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -170,11 +170,11 @@ public class UserApi {
     String localVarPath = "/user/createWithList".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -222,11 +222,11 @@ public class UserApi {
     String localVarPath = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -274,11 +274,11 @@ public class UserApi {
     String localVarPath = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -331,11 +331,11 @@ public class UserApi {
     String localVarPath = "/user/login".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
     localVarQueryParams.addAll(ApiInvoker.parameterToPairs("", "username", username));
     localVarQueryParams.addAll(ApiInvoker.parameterToPairs("", "password", password));
@@ -380,11 +380,11 @@ public class UserApi {
     String localVarPath = "/user/logout".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
@@ -437,11 +437,11 @@ public class UserApi {
     String localVarPath = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>();
     // header params
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarHeaderParams = new HashMap<>();
     // form params
-    Map<String, String> localVarFormParams = new HashMap<String, String>();
+    Map<String, String> localVarFormParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/ApiInvoker.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/ApiInvoker.java
index 9ff0422de5f99d16dfe31f426de9c635aedfe262..08177cfacbb7e76c532121012b3b83b9a80fb504 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/ApiInvoker.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/ApiInvoker.java
@@ -57,7 +57,7 @@ import org.openapitools.client.request.PatchRequest;
 
 public class ApiInvoker {
   private static ApiInvoker INSTANCE;
-  private Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private Map<String, String> defaultHeaderMap = new HashMap<>();
 
   private RequestQueue mRequestQueue;
 
@@ -137,7 +137,7 @@ public class ApiInvoker {
     Format to {@code Pair} objects.
   */
   public static List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -202,7 +202,7 @@ public class ApiInvoker {
     setUserAgent("OpenAPI-Generator/1.0.0/android");
 
     // Setup authentications (key: authentication name, value: authentication).
-    INSTANCE.authentications = new HashMap<String, Authentication>();
+    INSTANCE.authentications = new HashMap<>();
     INSTANCE.authentications.put("api_key", new ApiKeyAuth("header", "api_key"));
     // TODO: comment out below as OAuth does not exist
     //INSTANCE.authentications.put("petstore_auth", new OAuth());
@@ -410,7 +410,7 @@ public class ApiInvoker {
     String querystring = b.substring(0, b.length() - 1);
     String url = host + path + querystring;
 
-    HashMap<String, String> headers = new HashMap<String, String>();
+    HashMap<String, String> headers = new HashMap<>();
 
     for(String key : headerParams.keySet()) {
       headers.put(key, headerParams.get(key));
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/PetApi.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/PetApi.java
index a80910cd4c89b8733fd4c4b6ad144b4ef7e3c27a..2e3d41c5fbe8ed5fb694683d7e76fb9d8f122952 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/PetApi.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/PetApi.java
@@ -75,11 +75,11 @@ public class PetApi {
     String path = "/pet";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
       "application/json",
       "application/xml"
@@ -139,11 +139,11 @@ public class PetApi {
     String path = "/pet".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -201,11 +201,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     headerParams.put("api_key", ApiInvoker.parameterToString(apiKey));
     String[] contentTypes = {
     };
@@ -264,11 +264,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
     headerParams.put("api_key", ApiInvoker.parameterToString(apiKey));
@@ -326,11 +326,11 @@ public class PetApi {
     String path = "/pet/findByStatus";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     queryParams.addAll(ApiInvoker.parameterToPairs("csv", "status", status));
     String[] contentTypes = {
     };
@@ -389,11 +389,11 @@ public class PetApi {
     String path = "/pet/findByStatus".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
     queryParams.addAll(ApiInvoker.parameterToPairs("csv", "status", status));
 
@@ -455,11 +455,11 @@ public class PetApi {
     String path = "/pet/findByTags";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     queryParams.addAll(ApiInvoker.parameterToPairs("csv", "tags", tags));
     String[] contentTypes = {
     };
@@ -518,11 +518,11 @@ public class PetApi {
     String path = "/pet/findByTags".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
     queryParams.addAll(ApiInvoker.parameterToPairs("csv", "tags", tags));
 
@@ -584,11 +584,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -646,11 +646,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -711,11 +711,11 @@ public class PetApi {
     String path = "/pet";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
       "application/json",
       "application/xml"
@@ -775,11 +775,11 @@ public class PetApi {
     String path = "/pet".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -838,11 +838,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
       "application/x-www-form-urlencoded"
     };
@@ -909,11 +909,11 @@ public class PetApi {
     String path = "/pet/{petId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -982,11 +982,11 @@ formParams.put("status", ApiInvoker.parameterToString(status));
     String path = "/pet/{petId}/uploadImage".replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
       "multipart/form-data"
     };
@@ -1052,11 +1052,11 @@ formParams.put("status", ApiInvoker.parameterToString(status));
     String path = "/pet/{petId}/uploadImage".replaceAll("\\{format\\}","json").replaceAll("\\{" + "petId" + "\\}", apiInvoker.escapeString(petId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/StoreApi.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/StoreApi.java
index fd69b7573487c5d3f9c7bfeb71c917937d3b7968..02fee15f1f9df497bb5e5c849269c52f85415291 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/StoreApi.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/StoreApi.java
@@ -74,11 +74,11 @@ public class StoreApi {
     String path = "/store/order/{orderId}".replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -136,11 +136,11 @@ public class StoreApi {
     String path = "/store/order/{orderId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -191,11 +191,11 @@ public class StoreApi {
     String path = "/store/inventory";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -248,11 +248,11 @@ public class StoreApi {
     String path = "/store/inventory".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -313,11 +313,11 @@ public class StoreApi {
     String path = "/store/order/{orderId}".replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -375,11 +375,11 @@ public class StoreApi {
     String path = "/store/order/{orderId}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "orderId" + "\\}", apiInvoker.escapeString(orderId.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -440,11 +440,11 @@ public class StoreApi {
     String path = "/store/order";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -502,11 +502,11 @@ public class StoreApi {
     String path = "/store/order".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/UserApi.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/UserApi.java
index edec8bce95e95eb4a8fc2731ddae1a53a9a0d7e8..02c393ca6a9d8ea4c60e5196cad4b6409450dba5 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/UserApi.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/api/UserApi.java
@@ -74,11 +74,11 @@ public class UserApi {
     String path = "/user";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -136,11 +136,11 @@ public class UserApi {
     String path = "/user".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -197,11 +197,11 @@ public class UserApi {
     String path = "/user/createWithArray";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -259,11 +259,11 @@ public class UserApi {
     String path = "/user/createWithArray".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -320,11 +320,11 @@ public class UserApi {
     String path = "/user/createWithList";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -382,11 +382,11 @@ public class UserApi {
     String path = "/user/createWithList".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -443,11 +443,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -505,11 +505,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -566,11 +566,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -628,11 +628,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -699,11 +699,11 @@ public class UserApi {
     String path = "/user/login";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     queryParams.addAll(ApiInvoker.parameterToPairs("", "username", username));
     queryParams.addAll(ApiInvoker.parameterToPairs("", "password", password));
     String[] contentTypes = {
@@ -768,11 +768,11 @@ public class UserApi {
     String path = "/user/login".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
     queryParams.addAll(ApiInvoker.parameterToPairs("", "username", username));
     queryParams.addAll(ApiInvoker.parameterToPairs("", "password", password));
@@ -829,11 +829,11 @@ public class UserApi {
     String path = "/user/logout";
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -886,11 +886,11 @@ public class UserApi {
     String path = "/user/logout".replaceAll("\\{format\\}","json");
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
@@ -953,11 +953,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
     String[] contentTypes = {
     };
     String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
@@ -1020,11 +1020,11 @@ public class UserApi {
     String path = "/user/{username}".replaceAll("\\{format\\}","json").replaceAll("\\{" + "username" + "\\}", apiInvoker.escapeString(username.toString()));
 
     // query params
-    List<Pair> queryParams = new ArrayList<Pair>();
+    List<Pair> queryParams = new ArrayList<>();
     // header params
-    Map<String, String> headerParams = new HashMap<String, String>();
+    Map<String, String> headerParams = new HashMap<>();
     // form params
-    Map<String, String> formParams = new HashMap<String, String>();
+    Map<String, String> formParams = new HashMap<>();
 
 
 
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/DeleteRequest.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/DeleteRequest.java
index 387e52f102c062f69b577c4fd1db0952a91a4bd0..2e96d0f7252e4e6e85fe25c6884260d780ca0048 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/DeleteRequest.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/DeleteRequest.java
@@ -90,7 +90,7 @@ public class DeleteRequest extends Request<String> {
   public Map<String, String> getHeaders() throws AuthFailureError {
     Map<String, String> headers = super.getHeaders();
     if (headers == null || headers.equals(Collections.emptyMap())) {
-      headers = new HashMap<String, String>();
+      headers = new HashMap<>();
     }
     if (apiHeaders != null && !apiHeaders.equals(Collections.emptyMap())) {
       headers.putAll(apiHeaders);
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/GetRequest.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/GetRequest.java
index dd2c824098c0a3a8807b27a350a9f6d5f1cc39ce..a2f84a36817791e5735e848f5e17a6f6fccafda5 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/GetRequest.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/GetRequest.java
@@ -37,7 +37,7 @@ public class GetRequest extends StringRequest{
   public Map<String, String> getHeaders() throws AuthFailureError {
     Map<String, String> headers = super.getHeaders();
     if (headers == null || headers.equals(Collections.emptyMap())) {
-      headers = new HashMap<String, String>();
+      headers = new HashMap<>();
     }
     if (apiHeaders != null && !apiHeaders.equals(Collections.emptyMap())) {
       headers.putAll(apiHeaders);
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PatchRequest.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PatchRequest.java
index 4f97af9d06d9bf85913845c054959a5b38bcaa4e..38b516df849f898890a28059f90a79b9afa257b9 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PatchRequest.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PatchRequest.java
@@ -90,7 +90,7 @@ public class PatchRequest extends Request<String> {
   public Map<String, String> getHeaders() throws AuthFailureError {
     Map<String, String> headers = super.getHeaders();
     if (headers == null || headers.equals(Collections.emptyMap())) {
-      headers = new HashMap<String, String>();
+      headers = new HashMap<>();
     }
     if (apiHeaders != null && !apiHeaders.equals(Collections.emptyMap())) {
       headers.putAll(apiHeaders);
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PostRequest.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PostRequest.java
index dd4c40ddc85d89bc481e0e31a00afdd400181ab0..b7ee1ab912cd0e4865e5362415e394c80d99fb76 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PostRequest.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PostRequest.java
@@ -90,7 +90,7 @@ public class PostRequest extends Request<String> {
   public Map<String, String> getHeaders() throws AuthFailureError {
     Map<String, String> headers = super.getHeaders();
     if (headers == null || headers.equals(Collections.emptyMap())) {
-        headers = new HashMap<String, String>();
+        headers = new HashMap<>();
     }
     if (apiHeaders != null && !apiHeaders.equals(Collections.emptyMap())) {
         headers.putAll(apiHeaders);
diff --git a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PutRequest.java b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PutRequest.java
index 877d4855c440d82cc37935c0290812d882d4f5d0..f223bdd4a74782f5da999daf8e1928bd19bb4d03 100644
--- a/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PutRequest.java
+++ b/samples/client/petstore/android/volley/src/main/java/org/openapitools/client/request/PutRequest.java
@@ -90,7 +90,7 @@ public class PutRequest extends Request<String> {
   public Map<String, String> getHeaders() throws AuthFailureError {
     Map<String, String> headers = super.getHeaders();
     if (headers == null || headers.equals(Collections.emptyMap())) {
-      headers = new HashMap<String, String>();
+      headers = new HashMap<>();
     }
     if (apiHeaders != null && !apiHeaders.equals(Collections.emptyMap())) {
       headers.putAll(apiHeaders);
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/ApiClient.java
index 4e256daf6b29471a59d70de4c57f9eb7a95982c4..82c0054784170631fa7084a2333e507cd31f5410 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/ApiClient.java
@@ -34,7 +34,7 @@ public class ApiClient {
 
   public ApiClient() {
     objectMapper = createObjectMapper();
-    apiAuthorizations = new LinkedHashMap<String, RequestInterceptor>();
+    apiAuthorizations = new LinkedHashMap<>();
     feignBuilder = Feign.builder()
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new JacksonDecoder(objectMapper))
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/CustomInstantDeserializer.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/CustomInstantDeserializer.java
index 83d4514b071b9771a3ee4e52a2f3ba6e372b0397..20ad3c874e292e7baf30111474322ea29d289070 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/CustomInstantDeserializer.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/CustomInstantDeserializer.java
@@ -32,7 +32,7 @@ public class CustomInstantDeserializer<T extends Temporal>
     extends ThreeTenDateTimeDeserializerBase<T> {
   private static final long serialVersionUID = 1L;
 
-  public static final CustomInstantDeserializer<Instant> INSTANT = new CustomInstantDeserializer<Instant>(
+  public static final CustomInstantDeserializer<Instant> INSTANT = new CustomInstantDeserializer<>(
       Instant.class, DateTimeFormatter.ISO_INSTANT,
       new Function<TemporalAccessor, Instant>() {
         @Override
@@ -55,7 +55,7 @@ public class CustomInstantDeserializer<T extends Temporal>
       null
   );
 
-  public static final CustomInstantDeserializer<OffsetDateTime> OFFSET_DATE_TIME = new CustomInstantDeserializer<OffsetDateTime>(
+  public static final CustomInstantDeserializer<OffsetDateTime> OFFSET_DATE_TIME = new CustomInstantDeserializer<>(
       OffsetDateTime.class, DateTimeFormatter.ISO_OFFSET_DATE_TIME,
       new Function<TemporalAccessor, OffsetDateTime>() {
         @Override
@@ -83,7 +83,7 @@ public class CustomInstantDeserializer<T extends Temporal>
       }
   );
 
-  public static final CustomInstantDeserializer<ZonedDateTime> ZONED_DATE_TIME = new CustomInstantDeserializer<ZonedDateTime>(
+  public static final CustomInstantDeserializer<ZonedDateTime> ZONED_DATE_TIME = new CustomInstantDeserializer<>(
       ZonedDateTime.class, DateTimeFormatter.ISO_ZONED_DATE_TIME,
       new Function<TemporalAccessor, ZonedDateTime>() {
         @Override
@@ -151,7 +151,7 @@ public class CustomInstantDeserializer<T extends Temporal>
     if (dtf == _formatter) {
       return this;
     }
-    return new CustomInstantDeserializer<T>(this, dtf);
+    return new CustomInstantDeserializer<>(this, dtf);
   }
 
   @Override
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 8dffb4999596aca243c95db5072ae6a48ccdcb15..4b3082c2a9d52cd313fbe2709ef76aec4a0fe980 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -87,7 +87,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapStringItem(String key, String mapStringItem) {
     if (this.mapString == null) {
-      this.mapString = new HashMap<String, String>();
+      this.mapString = new HashMap<>();
     }
     this.mapString.put(key, mapStringItem);
     return this;
@@ -120,7 +120,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapNumberItem(String key, BigDecimal mapNumberItem) {
     if (this.mapNumber == null) {
-      this.mapNumber = new HashMap<String, BigDecimal>();
+      this.mapNumber = new HashMap<>();
     }
     this.mapNumber.put(key, mapNumberItem);
     return this;
@@ -153,7 +153,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapIntegerItem(String key, Integer mapIntegerItem) {
     if (this.mapInteger == null) {
-      this.mapInteger = new HashMap<String, Integer>();
+      this.mapInteger = new HashMap<>();
     }
     this.mapInteger.put(key, mapIntegerItem);
     return this;
@@ -186,7 +186,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapBooleanItem(String key, Boolean mapBooleanItem) {
     if (this.mapBoolean == null) {
-      this.mapBoolean = new HashMap<String, Boolean>();
+      this.mapBoolean = new HashMap<>();
     }
     this.mapBoolean.put(key, mapBooleanItem);
     return this;
@@ -219,7 +219,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapArrayIntegerItem(String key, List<Integer> mapArrayIntegerItem) {
     if (this.mapArrayInteger == null) {
-      this.mapArrayInteger = new HashMap<String, List<Integer>>();
+      this.mapArrayInteger = new HashMap<>();
     }
     this.mapArrayInteger.put(key, mapArrayIntegerItem);
     return this;
@@ -252,7 +252,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapArrayAnytypeItem(String key, List<Object> mapArrayAnytypeItem) {
     if (this.mapArrayAnytype == null) {
-      this.mapArrayAnytype = new HashMap<String, List<Object>>();
+      this.mapArrayAnytype = new HashMap<>();
     }
     this.mapArrayAnytype.put(key, mapArrayAnytypeItem);
     return this;
@@ -285,7 +285,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapMapStringItem(String key, Map<String, String> mapMapStringItem) {
     if (this.mapMapString == null) {
-      this.mapMapString = new HashMap<String, Map<String, String>>();
+      this.mapMapString = new HashMap<>();
     }
     this.mapMapString.put(key, mapMapStringItem);
     return this;
@@ -318,7 +318,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapMapAnytypeItem(String key, Map<String, Object> mapMapAnytypeItem) {
     if (this.mapMapAnytype == null) {
-      this.mapMapAnytype = new HashMap<String, Map<String, Object>>();
+      this.mapMapAnytype = new HashMap<>();
     }
     this.mapMapAnytype.put(key, mapMapAnytypeItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 5dc5abf298461300901d6ff7bdc07929127c6b8d..04028d28af4e413ad825df08939e727042e7a7cc 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -46,7 +46,7 @@ public class ArrayOfArrayOfNumberOnly {
 
   public ArrayOfArrayOfNumberOnly addArrayArrayNumberItem(List<BigDecimal> arrayArrayNumberItem) {
     if (this.arrayArrayNumber == null) {
-      this.arrayArrayNumber = new ArrayList<List<BigDecimal>>();
+      this.arrayArrayNumber = new ArrayList<>();
     }
     this.arrayArrayNumber.add(arrayArrayNumberItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c237ea37a6e29bc72ee9589633d0d238c26ef8a7..a1e54310438408ea5fa6168d9c45d170852c8fdb 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -46,7 +46,7 @@ public class ArrayOfNumberOnly {
 
   public ArrayOfNumberOnly addArrayNumberItem(BigDecimal arrayNumberItem) {
     if (this.arrayNumber == null) {
-      this.arrayNumber = new ArrayList<BigDecimal>();
+      this.arrayNumber = new ArrayList<>();
     }
     this.arrayNumber.add(arrayNumberItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayTest.java
index 8ca28d3862b8958484065337f981f66e1c76d788..10ee0b2ca102d25c554efc74af94aa31b23ef654 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -54,7 +54,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayOfStringItem(String arrayOfStringItem) {
     if (this.arrayOfString == null) {
-      this.arrayOfString = new ArrayList<String>();
+      this.arrayOfString = new ArrayList<>();
     }
     this.arrayOfString.add(arrayOfStringItem);
     return this;
@@ -87,7 +87,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayArrayOfIntegerItem(List<Long> arrayArrayOfIntegerItem) {
     if (this.arrayArrayOfInteger == null) {
-      this.arrayArrayOfInteger = new ArrayList<List<Long>>();
+      this.arrayArrayOfInteger = new ArrayList<>();
     }
     this.arrayArrayOfInteger.add(arrayArrayOfIntegerItem);
     return this;
@@ -120,7 +120,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayArrayOfModelItem(List<ReadOnlyFirst> arrayArrayOfModelItem) {
     if (this.arrayArrayOfModel == null) {
-      this.arrayArrayOfModel = new ArrayList<List<ReadOnlyFirst>>();
+      this.arrayArrayOfModel = new ArrayList<>();
     }
     this.arrayArrayOfModel.add(arrayArrayOfModelItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/EnumArrays.java
index 42c75cb2727dae43b40cb53e865cea92aac1433b..bf547f81f668bed9502e8466e8a6218408b62051 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -144,7 +144,7 @@ public class EnumArrays {
 
   public EnumArrays addArrayEnumItem(ArrayEnumEnum arrayEnumItem) {
     if (this.arrayEnum == null) {
-      this.arrayEnum = new ArrayList<ArrayEnumEnum>();
+      this.arrayEnum = new ArrayList<>();
     }
     this.arrayEnum.add(arrayEnumItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index aae40c4a5a6e0e96015d84e97839e601e11b1ada..7f12fa9001f29d938257adcb0b9ada1f38d14603 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -74,7 +74,7 @@ public class FileSchemaTestClass {
 
   public FileSchemaTestClass addFilesItem(java.io.File filesItem) {
     if (this.files == null) {
-      this.files = new ArrayList<java.io.File>();
+      this.files = new ArrayList<>();
     }
     this.files.add(filesItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MapTest.java
index 9621c8220b7182f779acf700301e9d61dc5d3b55..65e595487b45c818363c55e1ae7fde3bb5329e1f 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MapTest.java
@@ -93,7 +93,7 @@ public class MapTest {
 
   public MapTest putMapMapOfStringItem(String key, Map<String, String> mapMapOfStringItem) {
     if (this.mapMapOfString == null) {
-      this.mapMapOfString = new HashMap<String, Map<String, String>>();
+      this.mapMapOfString = new HashMap<>();
     }
     this.mapMapOfString.put(key, mapMapOfStringItem);
     return this;
@@ -126,7 +126,7 @@ public class MapTest {
 
   public MapTest putMapOfEnumStringItem(String key, InnerEnum mapOfEnumStringItem) {
     if (this.mapOfEnumString == null) {
-      this.mapOfEnumString = new HashMap<String, InnerEnum>();
+      this.mapOfEnumString = new HashMap<>();
     }
     this.mapOfEnumString.put(key, mapOfEnumStringItem);
     return this;
@@ -159,7 +159,7 @@ public class MapTest {
 
   public MapTest putDirectMapItem(String key, Boolean directMapItem) {
     if (this.directMap == null) {
-      this.directMap = new HashMap<String, Boolean>();
+      this.directMap = new HashMap<>();
     }
     this.directMap.put(key, directMapItem);
     return this;
@@ -192,7 +192,7 @@ public class MapTest {
 
   public MapTest putIndirectMapItem(String key, Boolean indirectMapItem) {
     if (this.indirectMap == null) {
-      this.indirectMap = new HashMap<String, Boolean>();
+      this.indirectMap = new HashMap<>();
     }
     this.indirectMap.put(key, indirectMapItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 3ccd9310b55c46799f3677c6b6e66be86d93fb3c..ea03dc29be3f4c00a73f611516a5377395a7b00d 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -107,7 +107,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
 
   public MixedPropertiesAndAdditionalPropertiesClass putMapItem(String key, Animal mapItem) {
     if (this.map == null) {
-      this.map = new HashMap<String, Animal>();
+      this.map = new HashMap<>();
     }
     this.map.put(key, mapItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/Pet.java
index 26446f5b488e21aa3f2d89d7693156cb8a2e64ed..37e6e7df60e99c735ab4780bf7feb5ff29f0e0b7 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/Pet.java
@@ -52,7 +52,7 @@ public class Pet {
   private String name;
 
   public static final String JSON_PROPERTY_PHOTO_URLS = "photoUrls";
-  private Set<String> photoUrls = new LinkedHashSet<String>();
+  private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
   private List<Tag> tags = null;
@@ -209,7 +209,7 @@ public class Pet {
 
   public Pet addTagsItem(Tag tagsItem) {
     if (this.tags == null) {
-      this.tags = new ArrayList<Tag>();
+      this.tags = new ArrayList<>();
     }
     this.tags.add(tagsItem);
     return this;
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 27199d76de1f6ee44b96db208c308ef3a220f75e..9b99685c8c78e7c87fab601200d3c5bfe5a23fb6 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -51,7 +51,7 @@ public class TypeHolderDefault {
   private Boolean boolItem = true;
 
   public static final String JSON_PROPERTY_ARRAY_ITEM = "array_item";
-  private List<Integer> arrayItem = new ArrayList<Integer>();
+  private List<Integer> arrayItem = new ArrayList<>();
 
 
   public TypeHolderDefault stringItem(String stringItem) {
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index f87fb944b9b43f760446e46a4f700ce6650ee23b..7c1cde29f50bfee94cd134cc65b53aed91737ca9 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -55,7 +55,7 @@ public class TypeHolderExample {
   private Boolean boolItem;
 
   public static final String JSON_PROPERTY_ARRAY_ITEM = "array_item";
-  private List<Integer> arrayItem = new ArrayList<Integer>();
+  private List<Integer> arrayItem = new ArrayList<>();
 
 
   public TypeHolderExample stringItem(String stringItem) {
diff --git a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/XmlItem.java
index 59b3ac5879a6315cff72d12ebbb95d1051c35234..f975f3d856477290e88bb9167268c2049ddb0cf1 100644
--- a/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/feign/feign10x/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -258,7 +258,7 @@ public class XmlItem {
 
   public XmlItem addWrappedArrayItem(Integer wrappedArrayItem) {
     if (this.wrappedArray == null) {
-      this.wrappedArray = new ArrayList<Integer>();
+      this.wrappedArray = new ArrayList<>();
     }
     this.wrappedArray.add(wrappedArrayItem);
     return this;
@@ -391,7 +391,7 @@ public class XmlItem {
 
   public XmlItem addNameArrayItem(Integer nameArrayItem) {
     if (this.nameArray == null) {
-      this.nameArray = new ArrayList<Integer>();
+      this.nameArray = new ArrayList<>();
     }
     this.nameArray.add(nameArrayItem);
     return this;
@@ -424,7 +424,7 @@ public class XmlItem {
 
   public XmlItem addNameWrappedArrayItem(Integer nameWrappedArrayItem) {
     if (this.nameWrappedArray == null) {
-      this.nameWrappedArray = new ArrayList<Integer>();
+      this.nameWrappedArray = new ArrayList<>();
     }
     this.nameWrappedArray.add(nameWrappedArrayItem);
     return this;
@@ -557,7 +557,7 @@ public class XmlItem {
 
   public XmlItem addPrefixArrayItem(Integer prefixArrayItem) {
     if (this.prefixArray == null) {
-      this.prefixArray = new ArrayList<Integer>();
+      this.prefixArray = new ArrayList<>();
     }
     this.prefixArray.add(prefixArrayItem);
     return this;
@@ -590,7 +590,7 @@ public class XmlItem {
 
   public XmlItem addPrefixWrappedArrayItem(Integer prefixWrappedArrayItem) {
     if (this.prefixWrappedArray == null) {
-      this.prefixWrappedArray = new ArrayList<Integer>();
+      this.prefixWrappedArray = new ArrayList<>();
     }
     this.prefixWrappedArray.add(prefixWrappedArrayItem);
     return this;
@@ -723,7 +723,7 @@ public class XmlItem {
 
   public XmlItem addNamespaceArrayItem(Integer namespaceArrayItem) {
     if (this.namespaceArray == null) {
-      this.namespaceArray = new ArrayList<Integer>();
+      this.namespaceArray = new ArrayList<>();
     }
     this.namespaceArray.add(namespaceArrayItem);
     return this;
@@ -756,7 +756,7 @@ public class XmlItem {
 
   public XmlItem addNamespaceWrappedArrayItem(Integer namespaceWrappedArrayItem) {
     if (this.namespaceWrappedArray == null) {
-      this.namespaceWrappedArray = new ArrayList<Integer>();
+      this.namespaceWrappedArray = new ArrayList<>();
     }
     this.namespaceWrappedArray.add(namespaceWrappedArrayItem);
     return this;
@@ -889,7 +889,7 @@ public class XmlItem {
 
   public XmlItem addPrefixNsArrayItem(Integer prefixNsArrayItem) {
     if (this.prefixNsArray == null) {
-      this.prefixNsArray = new ArrayList<Integer>();
+      this.prefixNsArray = new ArrayList<>();
     }
     this.prefixNsArray.add(prefixNsArrayItem);
     return this;
@@ -922,7 +922,7 @@ public class XmlItem {
 
   public XmlItem addPrefixNsWrappedArrayItem(Integer prefixNsWrappedArrayItem) {
     if (this.prefixNsWrappedArray == null) {
-      this.prefixNsWrappedArray = new ArrayList<Integer>();
+      this.prefixNsWrappedArray = new ArrayList<>();
     }
     this.prefixNsWrappedArray.add(prefixNsWrappedArrayItem);
     return this;
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 79c524a87ee3c673b8f40f443b02cdae9e0f8d8e..12a8d0179c32d4e7a00ac90dc456432d479c9ea8 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -53,7 +53,7 @@ public class TypeHolderDefault {
   private Boolean boolItem = true;
 
   public static final String JSON_PROPERTY_ARRAY_ITEM = "array_item";
-  private List<Integer> arrayItem = new ArrayList<Integer>();
+  private List<Integer> arrayItem = new ArrayList<>();
 
 
   public TypeHolderDefault stringItem(String stringItem) {
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 0ca2e109b3bc84a2c11e1368ab1ad5416e290d42..5264c53801ca24167c1604764a4201a2026d10c7 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -57,7 +57,7 @@ public class TypeHolderExample {
   private Boolean boolItem;
 
   public static final String JSON_PROPERTY_ARRAY_ITEM = "array_item";
-  private List<Integer> arrayItem = new ArrayList<Integer>();
+  private List<Integer> arrayItem = new ArrayList<>();
 
 
   public TypeHolderExample stringItem(String stringItem) {
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/XmlItem.java
index 3c3ba6befbb582b3c70081000e2b9743514fc2aa..451f9f61b619892f56beaa85c774890ee6e72145 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -268,7 +268,7 @@ public class XmlItem {
 
   public XmlItem addWrappedArrayItem(Integer wrappedArrayItem) {
     if (this.wrappedArray == null) {
-      this.wrappedArray = new ArrayList<Integer>();
+      this.wrappedArray = new ArrayList<>();
     }
     this.wrappedArray.add(wrappedArrayItem);
     return this;
@@ -411,7 +411,7 @@ public class XmlItem {
 
   public XmlItem addNameArrayItem(Integer nameArrayItem) {
     if (this.nameArray == null) {
-      this.nameArray = new ArrayList<Integer>();
+      this.nameArray = new ArrayList<>();
     }
     this.nameArray.add(nameArrayItem);
     return this;
@@ -446,7 +446,7 @@ public class XmlItem {
 
   public XmlItem addNameWrappedArrayItem(Integer nameWrappedArrayItem) {
     if (this.nameWrappedArray == null) {
-      this.nameWrappedArray = new ArrayList<Integer>();
+      this.nameWrappedArray = new ArrayList<>();
     }
     this.nameWrappedArray.add(nameWrappedArrayItem);
     return this;
@@ -589,7 +589,7 @@ public class XmlItem {
 
   public XmlItem addPrefixArrayItem(Integer prefixArrayItem) {
     if (this.prefixArray == null) {
-      this.prefixArray = new ArrayList<Integer>();
+      this.prefixArray = new ArrayList<>();
     }
     this.prefixArray.add(prefixArrayItem);
     return this;
@@ -624,7 +624,7 @@ public class XmlItem {
 
   public XmlItem addPrefixWrappedArrayItem(Integer prefixWrappedArrayItem) {
     if (this.prefixWrappedArray == null) {
-      this.prefixWrappedArray = new ArrayList<Integer>();
+      this.prefixWrappedArray = new ArrayList<>();
     }
     this.prefixWrappedArray.add(prefixWrappedArrayItem);
     return this;
@@ -767,7 +767,7 @@ public class XmlItem {
 
   public XmlItem addNamespaceArrayItem(Integer namespaceArrayItem) {
     if (this.namespaceArray == null) {
-      this.namespaceArray = new ArrayList<Integer>();
+      this.namespaceArray = new ArrayList<>();
     }
     this.namespaceArray.add(namespaceArrayItem);
     return this;
@@ -802,7 +802,7 @@ public class XmlItem {
 
   public XmlItem addNamespaceWrappedArrayItem(Integer namespaceWrappedArrayItem) {
     if (this.namespaceWrappedArray == null) {
-      this.namespaceWrappedArray = new ArrayList<Integer>();
+      this.namespaceWrappedArray = new ArrayList<>();
     }
     this.namespaceWrappedArray.add(namespaceWrappedArrayItem);
     return this;
@@ -945,7 +945,7 @@ public class XmlItem {
 
   public XmlItem addPrefixNsArrayItem(Integer prefixNsArrayItem) {
     if (this.prefixNsArray == null) {
-      this.prefixNsArray = new ArrayList<Integer>();
+      this.prefixNsArray = new ArrayList<>();
     }
     this.prefixNsArray.add(prefixNsArrayItem);
     return this;
@@ -980,7 +980,7 @@ public class XmlItem {
 
   public XmlItem addPrefixNsWrappedArrayItem(Integer prefixNsWrappedArrayItem) {
     if (this.prefixNsWrappedArray == null) {
-      this.prefixNsWrappedArray = new ArrayList<Integer>();
+      this.prefixNsWrappedArray = new ArrayList<>();
     }
     this.prefixNsWrappedArray.add(prefixNsWrappedArrayItem);
     return this;
diff --git a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/ApiClientTest.java
index dadb65fa1c5422b1a4b6372f0e80edc29109c0cd..e68b36c89f242d0ddd1edbdaca7fdc47930fc61c 100644
--- a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/ApiClientTest.java
+++ b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -202,7 +202,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairWhenValueIsCollection() throws Exception {
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
@@ -213,7 +213,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenNameIsInvalid() throws Exception {
-        List<Integer> objects = new ArrayList<Integer>();
+        List<Integer> objects = new ArrayList<>();
         objects.add(new Integer(1));
 
         List<Pair> pairs_a = apiClient.parameterToPairs("csv", null, objects);
@@ -233,7 +233,7 @@ public class ApiClientTest {
     @Test
     public void testParameterToPairsWhenValueIsEmptyStrings() throws Exception {
         // list of empty strings
-        List<String> strs = new ArrayList<String>();
+        List<String> strs = new ArrayList<>();
         strs.add(" ");
         strs.add(" ");
         strs.add(" ");
@@ -246,7 +246,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenValueIsCollection() throws Exception {
-        Map<String, String> collectionFormatMap = new HashMap<String, String>();
+        Map<String, String> collectionFormatMap = new HashMap<>();
         collectionFormatMap.put("csv", ",");
         collectionFormatMap.put("tsv", "\t");
         collectionFormatMap.put("ssv", " ");
@@ -256,7 +256,7 @@ public class ApiClientTest {
 
         String name = "param-a";
 
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
diff --git a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
index 02f5da4c2215d1286f780b2af15698167ddd2043..feb11e87a386fe77224803f2b16f7f0f897bcfbd 100644
--- a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
+++ b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
@@ -13,9 +13,9 @@ import static org.junit.Assert.*;
 public class ApiKeyAuthTest {
     @Test
     public void testApplyToParamsInQuery() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey("my-api-key");
@@ -33,9 +33,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithPrefix() {
-            List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+            List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -52,9 +52,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithPrefix() {
-            List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+            List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
diff --git a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
index 458e73e8a7e68c552cc130221f285825b436264e..2850f9f46df5e601a5f7fbc6135f4408eaee8f1b 100644
--- a/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
+++ b/samples/client/petstore/java/jersey1/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
@@ -20,9 +20,9 @@ public class HttpBasicAuthTest {
 
     @Test
     public void testApplyToParams() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         auth.setUsername("my-username");
         auth.setPassword("my-password");
diff --git a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
index 90a3758eba24bc69c8f089a1d00f2cca79dd9f68..585eb94de2cbc47943006ea721447862c3addc21 100644
--- a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -190,7 +190,7 @@ public class ApiClientTest {
         assertEquals(1, pairs.size());
 
         // list of empty strings
-        List<String> strs = new ArrayList<String>();
+        List<String> strs = new ArrayList<>();
         strs.add(" ");
         strs.add(" ");
         strs.add(" ");
@@ -214,7 +214,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenValueIsCollection() throws Exception {
-        Map<String, String> collectionFormatMap = new HashMap<String, String>();
+        Map<String, String> collectionFormatMap = new HashMap<>();
         collectionFormatMap.put("csv", ",");
         collectionFormatMap.put("tsv", "\t");
         collectionFormatMap.put("ssv", " ");
@@ -224,7 +224,7 @@ public class ApiClientTest {
 
         String name = "param-a";
 
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
diff --git a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
index 3e33515209283adcd12d36359f617ea6ba12b77f..76e3a0f30aa81e284d650b0f489bc4d96e945483 100644
--- a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
@@ -14,9 +14,9 @@ import static org.junit.Assert.*;
 public class ApiKeyAuthTest {
     @Test
     public void testApplyToParamsInQuery() throws ApiException {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey("my-api-key");
@@ -34,9 +34,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithPrefix() throws ApiException {
-            List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+            List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -52,9 +52,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithPrefix() throws ApiException {
-            List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+            List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
diff --git a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
index 88b2105e24f2afd05172dcdd50b35678edcc669d..8ee86d548aaa025cf03e80f1dec6b8b05dec0576 100644
--- a/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
@@ -21,9 +21,9 @@ public class HttpBasicAuthTest {
 
     @Test
     public void testApplyToParams() throws ApiException {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         auth.setUsername("my-username");
         auth.setPassword("my-password");
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/ApiClientTest.java
index 80f2bba66b0ee05a1e66df4c0582e8be1771df3b..82801dc03637bed7be0407e9460d6e406b4088ba 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/ApiClientTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -232,7 +232,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairWhenValueIsCollection() throws Exception {
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
@@ -243,7 +243,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenNameIsInvalid() throws Exception {
-        List<Integer> objects = new ArrayList<Integer>();
+        List<Integer> objects = new ArrayList<>();
         objects.add(new Integer(1));
 
         Parameter param = new Parameter().style(Parameter.StyleEnum.SIMPLE);
@@ -264,7 +264,7 @@ public class ApiClientTest {
     @Test
     public void testParameterToPairsWhenValueIsEmptyStrings() throws Exception {
         // list of empty strings
-        List<String> strs = new ArrayList<String>();
+        List<String> strs = new ArrayList<>();
         strs.add(" ");
         strs.add(" ");
         strs.add(" ");
@@ -279,14 +279,14 @@ public class ApiClientTest {
     public void testParameterToPairsWhenValueIsCollection() throws Exception {
         String name = "param-a";
 
-        Map<StyleEnum, String> parameterStyleMap = new HashMap<StyleEnum, String>();
+        Map<StyleEnum, String> parameterStyleMap = new HashMap<>();
         parameterStyleMap.put(StyleEnum.FORM, ",");
         parameterStyleMap.put(StyleEnum.SIMPLE, ",");
         parameterStyleMap.put(StyleEnum.SPACEDELIMITED, " ");
         parameterStyleMap.put(StyleEnum.PIPEDELIMITED, "|");
 
 
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/api/PetApiTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/api/PetApiTest.java
index f65184b608cd026857b473304335bb3d6f3df52e..e44c3bf2ee92e4e3214602a7dd2830a57d6a2ab2 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/api/PetApiTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/api/PetApiTest.java
@@ -116,7 +116,7 @@ public class PetApiTest {
         Pet pet = createPet();
         api.addPet(pet);
         // to store returned Pet or error message/exception
-        final Map<String, Object> result = new HashMap<String, Object>();
+        final Map<String, Object> result = new HashMap<>();
 
         api.getPetByIdAsync(pet.getId(), new ApiCallback<Pet>() {
             @Override
@@ -163,7 +163,7 @@ public class PetApiTest {
         Pet pet = createPet();
         api.addPet(pet);
         // to store returned Pet or error message/exception
-        final Map<String, Object> result = new HashMap<String, Object>();
+        final Map<String, Object> result = new HashMap<>();
 
         // test getting a nonexistent pet
         result.clear();
@@ -218,8 +218,8 @@ public class PetApiTest {
         Pet pet2 = createPet();
 
         final CountDownLatch addLatch = new CountDownLatch(2);
-        final TestApiCallback<Void> addCallback1 = new TestApiCallback<Void>(addLatch);
-        final TestApiCallback<Void> addCallback2 = new TestApiCallback<Void>(addLatch);
+        final TestApiCallback<Void> addCallback1 = new TestApiCallback<>(addLatch);
+        final TestApiCallback<Void> addCallback2 = new TestApiCallback<>(addLatch);
 
         // Make 2 simultaneous calls
         api.addPetAsync(pet1, addCallback1);
@@ -238,9 +238,9 @@ public class PetApiTest {
         assertValidProgress(addCallback2.getUploadProgress());
 
         final CountDownLatch getLatch = new CountDownLatch(3);
-        final TestApiCallback<Pet> getCallback1 = new TestApiCallback<Pet>(getLatch);
-        final TestApiCallback<Pet> getCallback2 = new TestApiCallback<Pet>(getLatch);
-        final TestApiCallback<Pet> getCallback3 = new TestApiCallback<Pet>(getLatch);
+        final TestApiCallback<Pet> getCallback1 = new TestApiCallback<>(getLatch);
+        final TestApiCallback<Pet> getCallback2 = new TestApiCallback<>(getLatch);
+        final TestApiCallback<Pet> getCallback3 = new TestApiCallback<>(getLatch);
 
         api.getPetByIdAsync(pet1.getId(), getCallback1);
         api.getPetByIdAsync(pet2.getId(), getCallback2);
@@ -318,7 +318,7 @@ public class PetApiTest {
         pet.setName("monster");
         pet.setStatus(Pet.StatusEnum.AVAILABLE);
 
-        List<Tag> tags = new ArrayList<Tag>();
+        List<Tag> tags = new ArrayList<>();
         Tag tag1 = new Tag();
         tag1.setName("friendly");
         tags.add(tag1);
@@ -480,9 +480,9 @@ public class PetApiTest {
 
         private final CountDownLatch latch;
         private final ConcurrentLinkedQueue<Progress> uploadProgress =
-                new ConcurrentLinkedQueue<Progress>();
+                new ConcurrentLinkedQueue<>();
         private final ConcurrentLinkedQueue<Progress> downloadProgress =
-                new ConcurrentLinkedQueue<Progress>();
+                new ConcurrentLinkedQueue<>();
 
         private boolean done;
         private boolean success;
@@ -537,11 +537,11 @@ public class PetApiTest {
         }
 
         public List<Progress> getUploadProgress() {
-            return new ArrayList<Progress>(uploadProgress);
+            return new ArrayList<>(uploadProgress);
         }
 
         public List<Progress> getDownloadProgress() {
-            return new ArrayList<Progress>(downloadProgress);
+            return new ArrayList<>(downloadProgress);
         }
     }
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
index da25043b27e6a1a5bc5465ebedde5a6c41723788..bbe5d0104ee82fdacd1ee28298da232a44fe684e 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
@@ -13,9 +13,9 @@ import static org.junit.Assert.*;
 public class ApiKeyAuthTest {
     @Test
     public void testApplyToParamsInQuery() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey("my-api-key");
@@ -33,9 +33,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInQueryWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey(null);
@@ -49,9 +49,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithPrefix() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -67,9 +67,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey(null);
@@ -84,9 +84,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithPrefix() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -102,9 +102,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey(null);
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
index e963ea24f7f300cbad5aebbba4478f4911cb3682..e9e7997c7ae31a26232371a9e8d85f18610cce2c 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
@@ -20,9 +20,9 @@ public class HttpBasicAuthTest {
 
     @Test
     public void testApplyToParams() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         auth.setUsername("my-username");
         auth.setPassword("my-password");
@@ -52,8 +52,8 @@ public class HttpBasicAuthTest {
         assertEquals(expected, headerParams.get("Authorization"));
 
         // null username and password should be ignored
-        queryParams = new ArrayList<Pair>();
-        headerParams = new HashMap<String, String>();
+        queryParams = new ArrayList<>();
+        headerParams = new HashMap<>();
         auth.setUsername(null);
         auth.setPassword(null);
         auth.applyToParams(queryParams, headerParams, cookieParams);
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
index 27121aec515e0e43ab24ff72aeee00f0dda11b66..437c45e9c0b973a49b95abe8ec5048ea092f24a5 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
@@ -50,20 +50,20 @@ public class ArrayOfArrayOfNumberOnlyTest {
     public void arrayArrayNumberTest() {
         BigDecimal b1 = new BigDecimal("12.3");
         BigDecimal b2 = new BigDecimal("5.6");
-        List<BigDecimal> arrayArrayNumber = new ArrayList<BigDecimal>();
+        List<BigDecimal> arrayArrayNumber = new ArrayList<>();
         arrayArrayNumber.add(b1);
         arrayArrayNumber.add(b2);
-        model.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
+        model.setArrayArrayNumber(new ArrayList<>());
         model.getArrayArrayNumber().add(arrayArrayNumber);
 
         // create another instance for comparison
         BigDecimal b3 = new BigDecimal("12.3");
         BigDecimal b4 = new BigDecimal("5.6");
         ArrayOfArrayOfNumberOnly model2 = new ArrayOfArrayOfNumberOnly();
-        List<BigDecimal> arrayArrayNumber2 = new ArrayList<BigDecimal>();
+        List<BigDecimal> arrayArrayNumber2 = new ArrayList<>();
         arrayArrayNumber2.add(b1);
         arrayArrayNumber2.add(b2);
-        model2.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
+        model2.setArrayArrayNumber(new ArrayList<>());
         model2.getArrayArrayNumber().add(arrayArrayNumber2);
 
         Assert.assertTrue(model2.equals(model));
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/ApiClientTest.java
index 626901593bd242029ba983cba5dd73139ed826b4..651b981488908ffa858772cc33e3c3f1ec5967b1 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/ApiClientTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -230,7 +230,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairWhenValueIsCollection() throws Exception {
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
@@ -241,7 +241,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenNameIsInvalid() throws Exception {
-        List<Integer> objects = new ArrayList<Integer>();
+        List<Integer> objects = new ArrayList<>();
         objects.add(new Integer(1));
 
         List<Pair> pairs_a = apiClient.parameterToPairs("csv", null, objects);
@@ -261,7 +261,7 @@ public class ApiClientTest {
     @Test
     public void testParameterToPairsWhenValueIsEmptyStrings() throws Exception {
         // list of empty strings
-        List<String> strs = new ArrayList<String>();
+        List<String> strs = new ArrayList<>();
         strs.add(" ");
         strs.add(" ");
         strs.add(" ");
@@ -274,7 +274,7 @@ public class ApiClientTest {
 
     @Test
     public void testParameterToPairsWhenValueIsCollection() throws Exception {
-        Map<String, String> collectionFormatMap = new HashMap<String, String>();
+        Map<String, String> collectionFormatMap = new HashMap<>();
         collectionFormatMap.put("csv", ",");
         collectionFormatMap.put("tsv", "\t");
         collectionFormatMap.put("ssv", " ");
@@ -284,7 +284,7 @@ public class ApiClientTest {
 
         String name = "param-a";
 
-        List<Object> values = new ArrayList<Object>();
+        List<Object> values = new ArrayList<>();
         values.add("value-a");
         values.add(123);
         values.add(new Date());
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/api/PetApiTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/api/PetApiTest.java
index f65184b608cd026857b473304335bb3d6f3df52e..e44c3bf2ee92e4e3214602a7dd2830a57d6a2ab2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/api/PetApiTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/api/PetApiTest.java
@@ -116,7 +116,7 @@ public class PetApiTest {
         Pet pet = createPet();
         api.addPet(pet);
         // to store returned Pet or error message/exception
-        final Map<String, Object> result = new HashMap<String, Object>();
+        final Map<String, Object> result = new HashMap<>();
 
         api.getPetByIdAsync(pet.getId(), new ApiCallback<Pet>() {
             @Override
@@ -163,7 +163,7 @@ public class PetApiTest {
         Pet pet = createPet();
         api.addPet(pet);
         // to store returned Pet or error message/exception
-        final Map<String, Object> result = new HashMap<String, Object>();
+        final Map<String, Object> result = new HashMap<>();
 
         // test getting a nonexistent pet
         result.clear();
@@ -218,8 +218,8 @@ public class PetApiTest {
         Pet pet2 = createPet();
 
         final CountDownLatch addLatch = new CountDownLatch(2);
-        final TestApiCallback<Void> addCallback1 = new TestApiCallback<Void>(addLatch);
-        final TestApiCallback<Void> addCallback2 = new TestApiCallback<Void>(addLatch);
+        final TestApiCallback<Void> addCallback1 = new TestApiCallback<>(addLatch);
+        final TestApiCallback<Void> addCallback2 = new TestApiCallback<>(addLatch);
 
         // Make 2 simultaneous calls
         api.addPetAsync(pet1, addCallback1);
@@ -238,9 +238,9 @@ public class PetApiTest {
         assertValidProgress(addCallback2.getUploadProgress());
 
         final CountDownLatch getLatch = new CountDownLatch(3);
-        final TestApiCallback<Pet> getCallback1 = new TestApiCallback<Pet>(getLatch);
-        final TestApiCallback<Pet> getCallback2 = new TestApiCallback<Pet>(getLatch);
-        final TestApiCallback<Pet> getCallback3 = new TestApiCallback<Pet>(getLatch);
+        final TestApiCallback<Pet> getCallback1 = new TestApiCallback<>(getLatch);
+        final TestApiCallback<Pet> getCallback2 = new TestApiCallback<>(getLatch);
+        final TestApiCallback<Pet> getCallback3 = new TestApiCallback<>(getLatch);
 
         api.getPetByIdAsync(pet1.getId(), getCallback1);
         api.getPetByIdAsync(pet2.getId(), getCallback2);
@@ -318,7 +318,7 @@ public class PetApiTest {
         pet.setName("monster");
         pet.setStatus(Pet.StatusEnum.AVAILABLE);
 
-        List<Tag> tags = new ArrayList<Tag>();
+        List<Tag> tags = new ArrayList<>();
         Tag tag1 = new Tag();
         tag1.setName("friendly");
         tags.add(tag1);
@@ -480,9 +480,9 @@ public class PetApiTest {
 
         private final CountDownLatch latch;
         private final ConcurrentLinkedQueue<Progress> uploadProgress =
-                new ConcurrentLinkedQueue<Progress>();
+                new ConcurrentLinkedQueue<>();
         private final ConcurrentLinkedQueue<Progress> downloadProgress =
-                new ConcurrentLinkedQueue<Progress>();
+                new ConcurrentLinkedQueue<>();
 
         private boolean done;
         private boolean success;
@@ -537,11 +537,11 @@ public class PetApiTest {
         }
 
         public List<Progress> getUploadProgress() {
-            return new ArrayList<Progress>(uploadProgress);
+            return new ArrayList<>(uploadProgress);
         }
 
         public List<Progress> getDownloadProgress() {
-            return new ArrayList<Progress>(downloadProgress);
+            return new ArrayList<>(downloadProgress);
         }
     }
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
index da25043b27e6a1a5bc5465ebedde5a6c41723788..bbe5d0104ee82fdacd1ee28298da232a44fe684e 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/ApiKeyAuthTest.java
@@ -13,9 +13,9 @@ import static org.junit.Assert.*;
 public class ApiKeyAuthTest {
     @Test
     public void testApplyToParamsInQuery() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey("my-api-key");
@@ -33,9 +33,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInQueryWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("query", "api_key");
         auth.setApiKey(null);
@@ -49,9 +49,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithPrefix() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -67,9 +67,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInHeaderWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("header", "X-API-TOKEN");
         auth.setApiKey(null);
@@ -84,9 +84,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithPrefix() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey("my-api-token");
@@ -102,9 +102,9 @@ public class ApiKeyAuthTest {
 
     @Test
     public void testApplyToParamsInCookieWithNullValue() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         ApiKeyAuth auth = new ApiKeyAuth("cookie", "X-API-TOKEN");
         auth.setApiKey(null);
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
index e963ea24f7f300cbad5aebbba4478f4911cb3682..e9e7997c7ae31a26232371a9e8d85f18610cce2c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/auth/HttpBasicAuthTest.java
@@ -20,9 +20,9 @@ public class HttpBasicAuthTest {
 
     @Test
     public void testApplyToParams() {
-        List<Pair> queryParams = new ArrayList<Pair>();
-        Map<String, String> headerParams = new HashMap<String, String>();
-        Map<String, String> cookieParams = new HashMap<String, String>();
+        List<Pair> queryParams = new ArrayList<>();
+        Map<String, String> headerParams = new HashMap<>();
+        Map<String, String> cookieParams = new HashMap<>();
 
         auth.setUsername("my-username");
         auth.setPassword("my-password");
@@ -52,8 +52,8 @@ public class HttpBasicAuthTest {
         assertEquals(expected, headerParams.get("Authorization"));
 
         // null username and password should be ignored
-        queryParams = new ArrayList<Pair>();
-        headerParams = new HashMap<String, String>();
+        queryParams = new ArrayList<>();
+        headerParams = new HashMap<>();
         auth.setUsername(null);
         auth.setPassword(null);
         auth.applyToParams(queryParams, headerParams, cookieParams);
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
index 27121aec515e0e43ab24ff72aeee00f0dda11b66..437c45e9c0b973a49b95abe8ec5048ea092f24a5 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnlyTest.java
@@ -50,20 +50,20 @@ public class ArrayOfArrayOfNumberOnlyTest {
     public void arrayArrayNumberTest() {
         BigDecimal b1 = new BigDecimal("12.3");
         BigDecimal b2 = new BigDecimal("5.6");
-        List<BigDecimal> arrayArrayNumber = new ArrayList<BigDecimal>();
+        List<BigDecimal> arrayArrayNumber = new ArrayList<>();
         arrayArrayNumber.add(b1);
         arrayArrayNumber.add(b2);
-        model.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
+        model.setArrayArrayNumber(new ArrayList<>());
         model.getArrayArrayNumber().add(arrayArrayNumber);
 
         // create another instance for comparison
         BigDecimal b3 = new BigDecimal("12.3");
         BigDecimal b4 = new BigDecimal("5.6");
         ArrayOfArrayOfNumberOnly model2 = new ArrayOfArrayOfNumberOnly();
-        List<BigDecimal> arrayArrayNumber2 = new ArrayList<BigDecimal>();
+        List<BigDecimal> arrayArrayNumber2 = new ArrayList<>();
         arrayArrayNumber2.add(b1);
         arrayArrayNumber2.add(b2);
-        model2.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
+        model2.setArrayArrayNumber(new ArrayList<>());
         model2.getArrayArrayNumber().add(arrayArrayNumber2);
 
         Assert.assertTrue(model2.equals(model));
diff --git a/samples/meta-codegen/lib/src/main/java/com/my/company/codegen/MyclientcodegenGenerator.java b/samples/meta-codegen/lib/src/main/java/com/my/company/codegen/MyclientcodegenGenerator.java
index 9f3c524b31aa6f58b24d120e6378bec29675a471..146fa69064f47835d119d9de351e6ca913c3ce85 100644
--- a/samples/meta-codegen/lib/src/main/java/com/my/company/codegen/MyclientcodegenGenerator.java
+++ b/samples/meta-codegen/lib/src/main/java/com/my/company/codegen/MyclientcodegenGenerator.java
@@ -111,7 +111,7 @@ public class MyclientcodegenGenerator extends DefaultCodegen implements CodegenC
     /**
      * Reserved words.  Override this with reserved words specific to your language
      */
-    reservedWords = new HashSet<String> (
+    reservedWords = new HashSet<> (
       Arrays.asList(
         "sample1",  // replace with static values
         "sample2")
@@ -137,7 +137,7 @@ public class MyclientcodegenGenerator extends DefaultCodegen implements CodegenC
      * Language Specific Primitives.  These types will not trigger imports by
      * the client generator
      */
-    languageSpecificPrimitives = new HashSet<String>(
+    languageSpecificPrimitives = new HashSet<>(
       Arrays.asList(
         "Type1",      // replace these with your types
         "Type2")
@@ -195,4 +195,4 @@ public class MyclientcodegenGenerator extends DefaultCodegen implements CodegenC
     //TODO: check that this logic is safe to escape quotation mark to avoid code injection
     return input.replace("\"", "\\\"");
   }
-}
\ No newline at end of file
+}
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
index 9239b5386b22cb1bc49bdab3f9f71d7230cfbab3..9b83634aa19cbb7fc897adeba89a75a8f40e35fe 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/ApiClientTest.java
@@ -61,7 +61,7 @@ public class ApiClientTest {
 
     @Test
     public void testUpdateParamsForAuth() throws Exception {
-        Map<String, String> headerParams = new HashMap<String, String>();
+        Map<String, String> headerParams = new HashMap<>();
         List<Pair> queryParams = new ArrayList<>();
 
         URI uri = new URI("/api/v1/telemetry/TimeSeries");
@@ -69,7 +69,7 @@ public class ApiClientTest {
         // auth name
         String[] authNames = {"http_signature_test"};
 
-        HashMap<String, Authentication> authMap = new HashMap<String, Authentication>();
+        HashMap<String, Authentication> authMap = new HashMap<>();
 
         HttpSignatureAuth signatureAuth = new HttpSignatureAuth("some-key-1", SigningAlgorithm.HS2019, Algorithm.RSA_SHA512, null,
                 null, Arrays.asList(new String[] { "(request-target)" }), 128L);
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/JSON.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/JSON.java
index 04d3f7c17996ed1a42d866fb4f7ca31fdb1e63bc..d0b7d5bda991e58fb7fdd0c8e7c1aaf747104fed 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/JSON.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/JSON.java
@@ -56,7 +56,7 @@ public class JSON {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -76,7 +76,7 @@ public class JSON {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/AnotherFakeApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/AnotherFakeApi.java
index 9e3aae365055808b3cd9cd7aa47070bdb799ba80..9adc287c76462a0cc6f512ba5baa1c8ec5afb832 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/AnotherFakeApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/AnotherFakeApi.java
@@ -102,7 +102,7 @@ public class AnotherFakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("call123testSpecialTags", localVarResponse);
       }
-      return new ApiResponse<Client>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Client>() {})
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/DefaultApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/DefaultApi.java
index 5dc086e5edb211205534bdec32007e1b4e8d053f..e1836036f17f46c87972926f4314c6135d37705d 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/DefaultApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/DefaultApi.java
@@ -100,7 +100,7 @@ public class DefaultApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fooGet", localVarResponse);
       }
-      return new ApiResponse<InlineResponseDefault>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<InlineResponseDefault>() {})
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
index 71f3084b35b27ba0fd5fe9cbe7c666298246a34b..9704833f3e59c60ccce1b579ed39467b6a599d42 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
@@ -109,7 +109,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fakeHealthGet", localVarResponse);
       }
-      return new ApiResponse<HealthCheckResult>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<HealthCheckResult>() {})
@@ -173,7 +173,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fakeOuterBooleanSerialize", localVarResponse);
       }
-      return new ApiResponse<Boolean>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Boolean>() {})
@@ -243,7 +243,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fakeOuterCompositeSerialize", localVarResponse);
       }
-      return new ApiResponse<OuterComposite>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<OuterComposite>() {})
@@ -313,7 +313,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fakeOuterNumberSerialize", localVarResponse);
       }
-      return new ApiResponse<BigDecimal>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<BigDecimal>() {})
@@ -383,7 +383,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("fakeOuterStringSerialize", localVarResponse);
       }
-      return new ApiResponse<String>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<String>() {})
@@ -451,7 +451,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("getArrayOfEnums", localVarResponse);
       }
-      return new ApiResponse<List<OuterEnum>>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<List<OuterEnum>>() {})
@@ -513,7 +513,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testBodyWithFileSchema", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -587,7 +587,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testBodyWithQueryParams", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -674,7 +674,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testClientModel", localVarResponse);
       }
-      return new ApiResponse<Client>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Client>() {})
@@ -772,7 +772,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testEndpointParameters", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -864,7 +864,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testEnumParameters", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -987,7 +987,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testGroupParameters", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -1156,7 +1156,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testInlineAdditionalProperties", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -1230,7 +1230,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testJsonFormData", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -1308,7 +1308,7 @@ public class FakeApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testQueryParameterCollectionFormat", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java
index 098b07e149e26f62e064eec34529cfe1c00a4398..cd7ebcddc27cd59622cfddd29d6267ceaac882db 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java
@@ -102,7 +102,7 @@ public class FakeClassnameTags123Api {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("testClassname", localVarResponse);
       }
-      return new ApiResponse<Client>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Client>() {})
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/PetApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/PetApi.java
index 4f2bfe172fe2bdcaa538aa3aae8bb867e770c64e..e473fd8637934e15782f83824ae2c66dff212fa7 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/PetApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/PetApi.java
@@ -102,7 +102,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("addPet", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -176,7 +176,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("deletePet", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -248,7 +248,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("findPetsByStatus", localVarResponse);
       }
-      return new ApiResponse<List<Pet>>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<List<Pet>>() {})
@@ -329,7 +329,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("findPetsByTags", localVarResponse);
       }
-      return new ApiResponse<List<Pet>>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<List<Pet>>() {})
@@ -406,7 +406,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("getPetById", localVarResponse);
       }
-      return new ApiResponse<Pet>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Pet>() {})
@@ -473,7 +473,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("updatePet", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -549,7 +549,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("updatePetWithForm", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -622,7 +622,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("uploadFile", localVarResponse);
       }
-      return new ApiResponse<ModelApiResponse>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<ModelApiResponse>() {})
@@ -695,7 +695,7 @@ public class PetApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("uploadFileWithRequiredFile", localVarResponse);
       }
-      return new ApiResponse<ModelApiResponse>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<ModelApiResponse>() {})
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/StoreApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/StoreApi.java
index 0bd1cd35ff4303460e47b4c28afc530c8312c88d..fecca946dc11a307cb6c1be76f54c1bca94d340d 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/StoreApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/StoreApi.java
@@ -100,7 +100,7 @@ public class StoreApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("deleteOrder", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -167,7 +167,7 @@ public class StoreApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("getInventory", localVarResponse);
       }
-      return new ApiResponse<Map<String, Integer>>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Map<String, Integer>>() {})
@@ -231,7 +231,7 @@ public class StoreApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("getOrderById", localVarResponse);
       }
-      return new ApiResponse<Order>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Order>() {})
@@ -300,7 +300,7 @@ public class StoreApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("placeOrder", localVarResponse);
       }
-      return new ApiResponse<Order>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Order>() {})
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/UserApi.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/UserApi.java
index 008303b316d28b6353733998be9517b8e9766b8d..415d97f4ca9f067575d0611a7097b079c830c3dc 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/UserApi.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/api/UserApi.java
@@ -100,7 +100,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("createUser", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -172,7 +172,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("createUsersWithArrayInput", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -244,7 +244,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("createUsersWithListInput", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -316,7 +316,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("deleteUser", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -385,7 +385,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("getUserByName", localVarResponse);
       }
-      return new ApiResponse<User>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<User>() {})
@@ -456,7 +456,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("loginUser", localVarResponse);
       }
-      return new ApiResponse<String>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<String>() {})
@@ -534,7 +534,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("logoutUser", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
@@ -598,7 +598,7 @@ public class UserApi {
       if (localVarResponse.statusCode()/ 100 != 2) {
         throw getApiException("updateUser", localVarResponse);
       }
-      return new ApiResponse<Void>(
+      return new ApiResponse<>(
           localVarResponse.statusCode(),
           localVarResponse.headers().map(),
           null
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
index f90886fb61924f41a6f16c6de6a77b76fa81b613..a7341e425ebcad87424153248b9c35e0d515c973 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
@@ -150,7 +150,7 @@ public class Animal {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("Cat", Cat.class);
   mappings.put("Dog", Dog.class);
   mappings.put("Animal", Animal.class);
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
index ddecc547360fb534d5ea5eb4f87f5a3be9956d92..8cac3f2617ca53f9dfbab6ba9c25b558abaf23e4 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
@@ -116,7 +116,7 @@ public class Cat extends Animal {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("Cat", Cat.class);
   JSON.registerDiscriminator(Cat.class, "className", mappings);
 }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
index b2fc54afa06af0fd15a5ba5258fc4d41c30c5434..a14a401d437025a4d9af9a45d8ab14008cc128d7 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -162,7 +162,7 @@ public class ChildCat extends ParentPet {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("ChildCat", ChildCat.class);
   JSON.registerDiscriminator(ChildCat.class, "pet_type", mappings);
 }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
index 9baad459f3af19a1285eb592318401ccb6352528..514e582cbc2362a5e34c5547151f7bf74c4acd3d 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
@@ -116,7 +116,7 @@ public class Dog extends Animal {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("Dog", Dog.class);
   JSON.registerDiscriminator(Dog.class, "className", mappings);
 }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
index 213c4d548c2e83ce2cfa2276714dfe9308ecdbf1..9d8fdac814b0ce36cfc0f37cab3448d8df68b428 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
@@ -199,7 +199,7 @@ public class Drawing extends HashMap<String, Fruit> {
   @JsonAnySetter
   public Drawing putAdditionalProperty(String key, Fruit value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Fruit>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Fruit.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Fruit.java
index 548e7ab3c36fc0fda80cae5486d50ed1978e59bc..7627871aa940237865a5970369a0798016074a58 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Fruit.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Fruit.java
@@ -197,12 +197,12 @@ public class Fruit extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/FruitReq.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/FruitReq.java
index c73123d08dd631f02713d296a4e717546f18dc67..87817f21879b86171748d6d31c83228ccf346486 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/FruitReq.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/FruitReq.java
@@ -204,12 +204,12 @@ public class FruitReq extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(AppleReq.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(AppleReq.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(BananaReq.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(BananaReq.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GmFruit.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GmFruit.java
index c6c672512da5face8b4018c657c150d91de625ee..65f0c5da1f1fc22469925eba9c8100fe9937efb0 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GmFruit.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GmFruit.java
@@ -120,7 +120,7 @@ public class GmFruit extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in anyOf
-    public static final Map<String, Class<?>> schemas = new HashMap<String, Class<?>>();
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
 
     public GmFruit() {
         super("anyOf", Boolean.FALSE);
@@ -157,12 +157,12 @@ public class GmFruit extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 85e70e350ac2956547077c52669b5000768f492a..31c868a7e1ce1339fa0f190dadcc693978d4f9d4 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -118,7 +118,7 @@ public class GrandparentAnimal {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("ChildCat", ChildCat.class);
   mappings.put("ParentPet", ParentPet.class);
   mappings.put("GrandparentAnimal", GrandparentAnimal.class);
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Mammal.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Mammal.java
index 9d1e871feb9aed74f327e609756c87eb286a5265..50e91e10b1ca9dc4655012d9db6ec8f8f00bfccd 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Mammal.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Mammal.java
@@ -235,7 +235,7 @@ public class Mammal extends AbstractOpenApiSchema {
         schemas.put("Zebra", Zebra.class);
         JSON.registerDescendants(Mammal.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Pig", Pig.class);
         mappings.put("whale", Whale.class);
         mappings.put("zebra", Zebra.class);
@@ -258,17 +258,17 @@ public class Mammal extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Pig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Pig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Whale.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Whale.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Zebra.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Zebra.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
index ae35e6746a70de704b480ca32754de54a3ee09cf..08b2a7c3f569a176e84093435500569710b0099d 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -566,7 +566,7 @@ public class NullableClass extends HashMap<String, Object> {
   @JsonAnySetter
   public NullableClass putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableShape.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableShape.java
index 77d27e3e2c0b8182cd6a3da60a13d859f1b23503..2294b6f6495b83966e66540b2025d9a415af98c7 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableShape.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableShape.java
@@ -200,7 +200,7 @@ public class NullableShape extends AbstractOpenApiSchema {
         schemas.put("Triangle", Triangle.class);
         JSON.registerDescendants(NullableShape.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("NullableShape", NullableShape.class);
@@ -227,12 +227,12 @@ public class NullableShape extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
index 2175d750c0025175ff3b85d9a7361eed1dcc9b92..ff9f01d11109ea8c4bddaaf2c99ce01422675188 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -86,7 +86,7 @@ public class ParentPet extends GrandparentAnimal {
 
 static {
   // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  Map<String, Class<?>> mappings = new HashMap<>();
   mappings.put("ChildCat", ChildCat.class);
   mappings.put("ParentPet", ParentPet.class);
   JSON.registerDiscriminator(ParentPet.class, "pet_type", mappings);
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pig.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pig.java
index e77218d922e582bdfabc629ebb27b68c58292f08..9f20fea046a4935e496a09706675495e968a8c66 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pig.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pig.java
@@ -198,7 +198,7 @@ public class Pig extends AbstractOpenApiSchema {
         schemas.put("DanishPig", DanishPig.class);
         JSON.registerDescendants(Pig.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("BasquePig", BasquePig.class);
         mappings.put("DanishPig", DanishPig.class);
         mappings.put("Pig", Pig.class);
@@ -220,12 +220,12 @@ public class Pig extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(BasquePig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(BasquePig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(DanishPig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(DanishPig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Quadrilateral.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Quadrilateral.java
index b2c184698dbe3e462a88f2779467369b6273992b..61ee2e53da3977bb8e5bf37ae3b0a76172eed5ee 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Quadrilateral.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Quadrilateral.java
@@ -198,7 +198,7 @@ public class Quadrilateral extends AbstractOpenApiSchema {
         schemas.put("SimpleQuadrilateral", SimpleQuadrilateral.class);
         JSON.registerDescendants(Quadrilateral.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("ComplexQuadrilateral", ComplexQuadrilateral.class);
         mappings.put("SimpleQuadrilateral", SimpleQuadrilateral.class);
         mappings.put("Quadrilateral", Quadrilateral.class);
@@ -220,12 +220,12 @@ public class Quadrilateral extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(ComplexQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(ComplexQuadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(SimpleQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(SimpleQuadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Shape.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Shape.java
index b29a366dad9a796572c3e30d4f9b63ade0c202b0..35f15c763bb8883db3ee19288f0c0c8636edc1d1 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Shape.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Shape.java
@@ -198,7 +198,7 @@ public class Shape extends AbstractOpenApiSchema {
         schemas.put("Triangle", Triangle.class);
         JSON.registerDescendants(Shape.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("Shape", Shape.class);
@@ -220,12 +220,12 @@ public class Shape extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeOrNull.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeOrNull.java
index 05598727e1356ebe26382b6db96330e9f3667615..7712e71eedde6c0df9d4d289aa8b1a2cd1ba421c 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeOrNull.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeOrNull.java
@@ -200,7 +200,7 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
         schemas.put("Triangle", Triangle.class);
         JSON.registerDescendants(ShapeOrNull.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("ShapeOrNull", ShapeOrNull.class);
@@ -227,12 +227,12 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Triangle.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Triangle.java
index 073b1c351f15b678062fc353615bdfb1977b26c1..505af080233634339d5475ff76bb30cf574d78d6 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Triangle.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Triangle.java
@@ -235,7 +235,7 @@ public class Triangle extends AbstractOpenApiSchema {
         schemas.put("ScaleneTriangle", ScaleneTriangle.class);
         JSON.registerDescendants(Triangle.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("EquilateralTriangle", EquilateralTriangle.class);
         mappings.put("IsoscelesTriangle", IsoscelesTriangle.class);
         mappings.put("ScaleneTriangle", ScaleneTriangle.class);
@@ -258,17 +258,17 @@ public class Triangle extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(EquilateralTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(EquilateralTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(IsoscelesTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(IsoscelesTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(ScaleneTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(ScaleneTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
diff --git a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
index fc19f618cb9d9d6e8feb50419010c48cda72e81b..24fe2ad8b10fdce055cff5ace5afca94b73dafdc 100644
--- a/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/openapi3/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
@@ -151,7 +151,7 @@ public class Zebra extends HashMap<String, Object> {
   @JsonAnySetter
   public Zebra putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
diff --git a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/PetApiController.java b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/PetApiController.java
index 4e520a049fc7207f1bc0504102742190bffc06af..4651033aee817dbadb4abed3ac6ae28e4b408a53 100644
--- a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/PetApiController.java
+++ b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/PetApiController.java
@@ -37,14 +37,14 @@ public class PetApiController implements PetApi {
     public ResponseEntity<Void> addPet(@ApiParam(value = "Pet object that needs to be added to the store" ,required=true )   @RequestBody Pet body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> deletePet(@ApiParam(value = "Pet id to delete",required=true ) @PathVariable("petId") Long petId,
         @ApiParam(value = "" ) @RequestHeader(value="api_key", required=false) String apiKey,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<List<Pet>> findPetsByStatus(@ApiParam(value = "Status values that need to be considered for filter", required = true, allowableValues = "available, pending, sold", defaultValue = "new ArrayList<>()")  @RequestParam(value = "status", required = true, defaultValue="new ArrayList<>()") List<String> status,
@@ -52,15 +52,15 @@ public class PetApiController implements PetApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<List<Pet>>(objectMapper.readValue("", List.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", List.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<List<Pet>>(objectMapper.readValue("", List.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", List.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<List<Pet>>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<List<Pet>> findPetsByTags(@ApiParam(value = "Tags to filter by", required = true, defaultValue = "new ArrayList<>()")  @RequestParam(value = "tags", required = true, defaultValue="new ArrayList<>()") List<String> tags,
@@ -68,15 +68,15 @@ public class PetApiController implements PetApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<List<Pet>>(objectMapper.readValue("", List.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", List.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<List<Pet>>(objectMapper.readValue("", List.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", List.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<List<Pet>>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Pet> getPetById(@ApiParam(value = "ID of pet to return",required=true ) @PathVariable("petId") Long petId,
@@ -84,21 +84,21 @@ public class PetApiController implements PetApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<Pet>(objectMapper.readValue("", Pet.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Pet.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<Pet>(objectMapper.readValue("", Pet.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Pet.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<Pet>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> updatePet(@ApiParam(value = "Pet object that needs to be added to the store" ,required=true )   @RequestBody Pet body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> updatePetWithForm(@ApiParam(value = "ID of pet that needs to be updated",required=true ) @PathVariable("petId") Long petId,
@@ -106,7 +106,7 @@ public class PetApiController implements PetApi {
         @ApiParam(value = "Updated status of the pet") @RequestPart(value="status", required=false)  String status,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<ModelApiResponse> uploadFile(@ApiParam(value = "ID of pet to update",required=true ) @PathVariable("petId") Long petId,
@@ -116,10 +116,10 @@ public class PetApiController implements PetApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<ModelApiResponse>(objectMapper.readValue("", ModelApiResponse.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", ModelApiResponse.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<ModelApiResponse>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
 }
diff --git a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/StoreApiController.java b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/StoreApiController.java
index 8583b8b0a562ed4c814ca849f3231a8fb82f9fa1..f6eb0e9f18d0f72a08ca4a9d685bdaddbe5bd56d 100644
--- a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/StoreApiController.java
+++ b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/StoreApiController.java
@@ -36,12 +36,12 @@ public class StoreApiController implements StoreApi {
     public ResponseEntity<Void> deleteOrder(@ApiParam(value = "ID of the order that needs to be deleted",required=true ) @PathVariable("orderId") String orderId,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Map<String, Integer>> getInventory(@RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Map<String, Integer>>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Order> getOrderById(@ApiParam(value = "ID of pet that needs to be fetched",required=true ) @PathVariable("orderId") Long orderId,
@@ -49,15 +49,15 @@ public class StoreApiController implements StoreApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<Order>(objectMapper.readValue("", Order.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Order.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<Order>(objectMapper.readValue("", Order.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Order.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<Order>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Order> placeOrder(@ApiParam(value = "order placed for purchasing the pet" ,required=true )   @RequestBody Order body,
@@ -65,15 +65,15 @@ public class StoreApiController implements StoreApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<Order>(objectMapper.readValue("", Order.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Order.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<Order>(objectMapper.readValue("", Order.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", Order.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<Order>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
 }
diff --git a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/UserApiController.java b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/UserApiController.java
index 409941aa9494aff1fb2bc427f317de95b1f458d9..7079eae3197995b52187d237c1ca7d06be2a1e88 100644
--- a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/UserApiController.java
+++ b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/controller/UserApiController.java
@@ -36,25 +36,25 @@ public class UserApiController implements UserApi {
     public ResponseEntity<Void> createUser(@ApiParam(value = "Created user object" ,required=true )   @RequestBody User body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> createUsersWithArrayInput(@ApiParam(value = "List of user object" ,required=true )   @RequestBody List<User> body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> createUsersWithListInput(@ApiParam(value = "List of user object" ,required=true )   @RequestBody List<User> body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> deleteUser(@ApiParam(value = "The name that needs to be deleted",required=true ) @PathVariable("username") String username,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<User> getUserByName(@ApiParam(value = "The name that needs to be fetched. Use user1 for testing.",required=true ) @PathVariable("username") String username,
@@ -62,34 +62,34 @@ public class UserApiController implements UserApi {
         // do some magic!
 
         if (accept != null && accept.contains("application/json")) {
-            return new ResponseEntity<User>(objectMapper.readValue("", User.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", User.class), HttpStatus.OK);
         }
 
 
         if (accept != null && accept.contains("application/xml")) {
-            return new ResponseEntity<User>(objectMapper.readValue("", User.class), HttpStatus.OK);
+            return new ResponseEntity<>(objectMapper.readValue("", User.class), HttpStatus.OK);
         }
 
-        return new ResponseEntity<User>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<String> loginUser(@ApiParam(value = "The user name for login", required = true)  @RequestParam(value = "username", required = true) String username,
         @ApiParam(value = "The password for login in clear text", required = true)  @RequestParam(value = "password", required = true) String password,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<String>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> logoutUser(@RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     public ResponseEntity<Void> updateUser(@ApiParam(value = "name that need to be deleted",required=true ) @PathVariable("username") String username,
         @ApiParam(value = "Updated user object" ,required=true )   @RequestBody User body,
         @RequestHeader(value = "Accept", required = false) String accept) throws Exception {
         // do some magic!
-        return new ResponseEntity<Void>(HttpStatus.OK);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
 }
diff --git a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/logging/HttpLoggingFilter.java b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/logging/HttpLoggingFilter.java
index 4cd35871f6713468012c4f16044400f7faad1f9e..e2a12021a7360d1f6f3c58112f97f95e96f6d298 100644
--- a/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/logging/HttpLoggingFilter.java
+++ b/samples/server/petstore/java-pkmst/src/main/java/com/prokarma/pkmst/logging/HttpLoggingFilter.java
@@ -92,7 +92,7 @@ public class HttpLoggingFilter implements Filter {
   }
 
   private Map<String, String> getTypesafeRequestMap(HttpServletRequest request) {
-    Map<String, String> typesafeRequestMap = new HashMap<String, String>();
+    Map<String, String> typesafeRequestMap = new HashMap<>();
     Enumeration<?> requestParamNames = request.getParameterNames();
     while (requestParamNames.hasMoreElements()) {
       String requestParamName = (String) requestParamNames.nextElement();