Add support for using Spring HATEOAS to add links in the spring gener…

Created by: mwoodland

…ator.

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
• Filed the PR against the correct branch: master, 3.4.x, 4.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

Description of the PR

(details of the change, additional tests that have been done, reference to the issue for tracking, etc)

docs/generators/spring.md

@@ -155,6 +155,9 @@ CONFIG OPTIONS for spring
 	useOptional
 	    Use Optional container for optional parameters (Default: false)
 
+	hateoas
+	    Use Spring HATEOAS library to allow adding HATEOAS links (Default: false)
+
 	library
 	    library template (sub-template) to use (Default: spring-boot)
 	        spring-boot - Spring-boot Server application using the SpringFox integration.

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java

@@ -74,6 +74,7 @@ public class SpringCodegen extends AbstractJavaCodegen
     public static final String IMPLICIT_HEADERS = "implicitHeaders";
     public static final String OPENAPI_DOCKET_CONFIG = "swaggerDocketConfig";
     public static final String API_FIRST = "apiFirst";
+    public static final String HATEOAS = "hateoas";
 
     protected String title = "OpenAPI Spring";
     protected String configPackage = "org.openapitools.configuration";
@@ -93,6 +94,7 @@ public class SpringCodegen extends AbstractJavaCodegen
     protected boolean apiFirst = false;
     protected boolean useOptional = false;
     protected boolean virtualService = false;
+    protected boolean hateoas = false;
 
     public SpringCodegen() {
         super();
@@ -124,6 +126,7 @@ public class SpringCodegen extends AbstractJavaCodegen
         cliOptions.add(CliOption.newBoolean(OPENAPI_DOCKET_CONFIG, "Generate Spring OpenAPI Docket configuration class.", openapiDocketConfig));
         cliOptions.add(CliOption.newBoolean(API_FIRST, "Generate the API from the OAI spec at server compile time (API first approach)", apiFirst));
         cliOptions.add(CliOption.newBoolean(USE_OPTIONAL,"Use Optional container for optional parameters", useOptional));
+        cliOptions.add(CliOption.newBoolean(HATEOAS, "Use Spring HATEOAS library to allow adding HATEOAS links", hateoas));
 
         supportedLibraries.put(SPRING_BOOT, "Spring-boot Server application using the SpringFox integration.");
         supportedLibraries.put(SPRING_MVC_LIBRARY, "Spring-MVC Server application using the SpringFox integration.");
@@ -258,6 +261,10 @@ public class SpringCodegen extends AbstractJavaCodegen
         if (additionalProperties.containsKey(API_FIRST)) {
             this.setApiFirst(Boolean.valueOf(additionalProperties.get(API_FIRST).toString()));
         }
+        
+        if (additionalProperties.containsKey(HATEOAS)) {
+            this.setHateoas(Boolean.valueOf(additionalProperties.get(HATEOAS).toString()));
+        }
 
         typeMapping.put("file", "Resource");
         importMapping.put("Resource", "org.springframework.core.io.Resource");
@@ -698,6 +705,10 @@ public class SpringCodegen extends AbstractJavaCodegen
     public void setApiFirst(boolean apiFirst) {
         this.apiFirst = apiFirst;
     }
+    
+    public void setHateoas(boolean hateoas) {
+        this.hateoas = hateoas;
+    }
 
     @Override
     public void postProcessModelProperty(CodegenModel model, CodegenProperty property) {

modules/openapi-generator/src/main/resources/JavaSpring/libraries/spring-boot/pom.mustache

@@ -155,5 +155,12 @@
         </dependency>
     <!-- END Virtual Service API support -->
 {{/virtualService}}
+{{#hateoas}}
+        <!-- Spring HATEOAS -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-hateoas</artifactId>
+        </dependency>
+{{/hateoas}}
     </dependencies>
 </project>

modules/openapi-generator/src/main/resources/JavaSpring/model.mustache

@@ -19,6 +19,11 @@ import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
 {{#withXml}}
 import javax.xml.bind.annotation.*;
 {{/withXml}}
+{{^parent}}
+{{#hateoas}}
+import org.springframework.hateoas.ResourceSupport;
+{{/hateoas}}
+{{/parent}}
 
 {{#models}}
 {{#model}}

modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache

@@ -3,7 +3,7 @@
  */{{#description}}
 @ApiModel(description = "{{{description}}}"){{/description}}
 {{>generatedAnnotation}}{{#discriminator}}{{>typeInfoAnnotation}}{{/discriminator}}{{>xmlAnnotation}}
-public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#serializableModel}}implements Serializable{{/serializableModel}} {
+public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}}{{^parent}}{{#hateoas}}extends ResourceSupport {{/hateoas}}{{/parent}} {{#serializableModel}}implements Serializable{{/serializableModel}} {
 {{#serializableModel}}
   private static final long serialVersionUID = 1L;