diff --git a/.github/workflows/samples-java-client-echo-api-jdk8.yaml b/.github/workflows/samples-java-client-echo-api-jdk8.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..dbcf0fe398099eebc785cceda6f68d82c5147182
--- /dev/null
+++ b/.github/workflows/samples-java-client-echo-api-jdk8.yaml
@@ -0,0 +1,45 @@
+name: Java Client (Echo API) JDK8
+
+on:
+  push:
+    paths:
+      - samples/client/echo_api/java/apache-httpclient/**
+      - samples/client/echo_api/java/feign-gson/**
+  pull_request:
+    paths:
+      - samples/client/echo_api/java/apache-httpclient/**
+      - samples/client/echo_api/java/feign-gson/**
+jobs:
+  build:
+    name: Build Java Client JDK8
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          # clients
+          - samples/client/echo_api/java/apache-httpclient
+          - samples/client/echo_api/java/feign-gson
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: 8
+      - name: Cache maven dependencies
+        uses: actions/cache@v3
+        env:
+          cache-name: maven-repository
+        with:
+          path: |
+            ~/.m2
+          key: ${{ runner.os }}-${{ github.job }}-${{ env.cache-name }}-${{ hashFiles('**/pom.xml') }}
+      - name: Setup node.js
+        uses: actions/setup-node@v3
+      - name: Run echo server
+        run: |
+          git clone https://github.com/wing328/http-echo-server -b openapi-generator-test-server
+          (cd http-echo-server && npm install && npm start &)
+      - name: Build
+        working-directory: ${{ matrix.sample }}
+        run: mvn clean package
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 68eefa208c1f3577e7a0723a53dba4a4c6a605a0..7d4e72de167a607c9922170964ef9e2cff9a82ff 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
@@ -427,6 +427,13 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             this.webclientBlockingOperations = Boolean.parseBoolean(additionalProperties.get(WEBCLIENT_BLOCKING_OPERATIONS).toString());
         }
 
+        // add URL query deepObject support to native, apache-httpclient by default
+        if (!additionalProperties.containsKey("supportUrlQueryDeepObject") && (isLibrary(NATIVE) || isLibrary(APACHE))) {
+            additionalProperties.put("supportUrlQueryDeepObject", true);
+        } else {
+            additionalProperties.put("supportUrlQueryDeepObject", Boolean.parseBoolean(additionalProperties.get(SUPPORT_STREAMING).toString()));
+        }
+
         final String invokerFolder = (sourceFolder + '/' + invokerPackage).replace(".", "/");
         final String apiFolder = (sourceFolder + '/' + apiPackage).replace(".", "/");
         final String modelsFolder = (sourceFolder + File.separator + modelPackage().replace('.', File.separatorChar)).replace('/', File.separatorChar);
@@ -471,11 +478,6 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             }
         }
 
-        // add URL query deepObject support to native, apache-httpclient by default
-        if (!additionalProperties.containsKey("supportUrlQueryDeepObject") && (isLibrary(NATIVE) || isLibrary(APACHE))) {
-            additionalProperties.put("supportUrlQueryDeepObject", true);
-        }
-
         supportingFiles.add(new SupportingFile("gradlew.mustache", "", "gradlew"));
         supportingFiles.add(new SupportingFile("gradlew.bat.mustache", "", "gradlew.bat"));
         supportingFiles.add(new SupportingFile("gradle-wrapper.properties.mustache",
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
index 7059df6b64625f80a28cbd7a58562b5d848a517f..1536a05db62e2c31af22cefae1af0c8f8cc6e882 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
@@ -338,7 +338,7 @@ public class {{classname}} {
 
     {{#hasQueryParams}}
     {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<>();
-    StringJoiner localVarQueryDeepObjectStringJoiner = new StringJoiner("&");
+    {{javaUtilPrefix}}StringJoiner localVarQueryDeepObjectStringJoiner = new {{javaUtilPrefix}}StringJoiner("&");
     String localVarQueryParameterBaseName;
     {{#queryParams}}
     localVarQueryParameterBaseName = "{{{baseName}}}";
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/model.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/model.mustache
index 634850965bb011b1de34fa0ddbef9af21db65932..0bab3ea7919799483d9e21167508d1b4d0279e88 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/model.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/model.mustache
@@ -16,13 +16,15 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 {{/additionalPropertiesType}}
 {{/model}}
 {{/models}}
+{{#supportUrlQueryDeepObject}}
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
+{{/supportUrlQueryDeepObject}}
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 {{#imports}}
 import {{import}};
 {{/imports}}
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/modelEnum.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/modelEnum.mustache
index 91af79e12e8210af997f24e9c42c0b400f9749b6..8126b906b1babb4a8ffeb6f1f6a985992b71560a 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/modelEnum.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/modelEnum.mustache
@@ -62,6 +62,7 @@ import com.google.gson.stream.JsonWriter;
     }
     {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}{{#enumUnknownDefaultCase}}{{#allowableValues}}{{#enumVars}}{{#-last}}return {{{name}}};{{/-last}}{{/enumVars}}{{/allowableValues}}{{/enumUnknownDefaultCase}}{{^enumUnknownDefaultCase}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/enumUnknownDefaultCase}}{{/isNullable}}
   }
+{{#supportUrlQueryDeepObject}}
 
   /**
    * Convert the instance into URL query string.
@@ -76,6 +77,7 @@ import com.google.gson.stream.JsonWriter;
 
     return String.format("%s=%s", prefix, this.toString());
   }
+{{/supportUrlQueryDeepObject}}
 
 {{#gson}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
index 9af7a44e9b1ebe79ddfdad31411c6a552541610c..62f88ec74e33e4c9db0dce403b2f4f360954f4f5 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
@@ -348,7 +348,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     }
     return o.toString().replace("\n", "\n    ");
   }
-
+{{#supportUrlQueryDeepObject}}
 
   /**
    * Convert the instance into URL query string.
@@ -474,6 +474,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     {{/allVars}}
     return joiner.toString();
   }
+{{/supportUrlQueryDeepObject}}
 {{#parcelableModel}}
 
   public void writeToParcel(Parcel out, int flags) {
diff --git a/modules/openapi-generator/src/main/resources/Java/model.mustache b/modules/openapi-generator/src/main/resources/Java/model.mustache
index 188bbe316f9622e4be86a32c652569015ebd4683..361718411ad32d51b65dabf74619182c36d9afbb 100644
--- a/modules/openapi-generator/src/main/resources/Java/model.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/model.mustache
@@ -56,8 +56,8 @@ import {{javaxPackage}}.validation.Valid;
 import org.hibernate.validator.constraints.*;
 {{/performBeanValidation}}
 {{#supportUrlQueryDeepObject}}
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 {{/supportUrlQueryDeepObject}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
index ac1ba8391b58d52b9f8d6a89cbca343d0659088b..f7bf0dc2965f9718d7d0076d8794e1fc41770a9f 100644
--- a/modules/openapi-generator/src/main/resources/Java/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
@@ -357,7 +357,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     if ({{getter}}() != null) {
       int i = 0;
       for ({{items.dataType}} _item : {{getter}}()) {
-        joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
       i++;
     }
@@ -365,7 +370,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     {{^uniqueItems}}
     if ({{getter}}() != null) {
       for (int i = 0; i < {{getter}}().size(); i++) {
-        joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf({{getter}}().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf({{getter}}().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     {{/uniqueItems}}
@@ -399,7 +409,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
       int i = 0;
       for ({{items.dataType}} _item : {{getter}}()) {
         if (_item != null) {
-          joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          try {
+            joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), "UTF-8").replaceAll("\\+", "%20")));
+          } catch (UnsupportedEncodingException e) {
+            // Should never happen, UTF-8 is always supported
+            throw new RuntimeException(e);
+          }
         }
         i++;
       }
@@ -409,7 +424,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     if ({{getter}}() != null) {
       for (int i = 0; i < {{getter}}().size(); i++) {
         if ({{getter}}().get(i) != null) {
-          joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf({{getter}}().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          try {
+            joiner.add(String.format("%s[{{baseName}}][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf({{getter}}().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+          } catch (UnsupportedEncodingException e) {
+            // Should never happen, UTF-8 is always supported
+            throw new RuntimeException(e);
+          }
         }
       }
     }
@@ -422,7 +442,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     {{#items.isPrimitiveType}}
     if ({{getter}}() != null) {
       for (String _key : {{getter}}().keySet()) {
-        joiner.add(String.format("%s[{{baseName}}][%s]=%s", prefix, {{getter}}().get(_key), URLEncoder.encode(String.valueOf({{getter}}().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[{{baseName}}][%s]=%s", prefix, {{getter}}().get(_key), URLEncoder.encode(String.valueOf({{getter}}().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     {{/items.isPrimitiveType}}
@@ -439,7 +464,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     {{^isMap}}
     {{#isPrimitiveType}}
     if ({{getter}}() != null) {
-      joiner.add(String.format("%s[{{{baseName}}}]=%s", prefix, URLEncoder.encode(String.valueOf({{{getter}}}()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[{{{baseName}}}]=%s", prefix, URLEncoder.encode(String.valueOf({{{getter}}}()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     {{/isPrimitiveType}}
     {{^isPrimitiveType}}
@@ -450,7 +480,12 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     {{/isModel}}
     {{^isModel}}
     if ({{getter}}() != null) {
-      joiner.add(String.format("%s[{{{baseName}}}]=%s", prefix, URLEncoder.encode(String.valueOf({{{getter}}}()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[{{{baseName}}}]=%s", prefix, URLEncoder.encode(String.valueOf({{{getter}}}()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     {{/isModel}}
     {{/isPrimitiveType}}
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
index 62cb5fbc27cb84f5224a48463d354d8fd4c26849..1c04169e74ea5ac84dfca64f03f020ef665cca7b 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -148,11 +148,21 @@ public class Bird {
     StringJoiner joiner = new StringJoiner("&");
     // add `size` to the URL query string
     if (getSize() != null) {
-      joiner.add(String.format("%s[size]=%s", prefix, URLEncoder.encode(String.valueOf(getSize()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[size]=%s", prefix, URLEncoder.encode(String.valueOf(getSize()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `color` to the URL query string
     if (getColor() != null) {
-      joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/BirdAndCategory.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/BirdAndCategory.java
index b2a2ce698b13325d390bb82518656d4a7cf96ea3..7d9216b1074814837ab32fcae726b4f92fed4bb6 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/BirdAndCategory.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/BirdAndCategory.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -212,19 +212,39 @@ public class BirdAndCategory {
     StringJoiner joiner = new StringJoiner("&");
     // add `size` to the URL query string
     if (getSize() != null) {
-      joiner.add(String.format("%s[size]=%s", prefix, URLEncoder.encode(String.valueOf(getSize()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[size]=%s", prefix, URLEncoder.encode(String.valueOf(getSize()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `color` to the URL query string
     if (getColor() != null) {
-      joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
index 49c15db4b2815f9a15ac5ba51274b59a341583f8..83a32b0e607042f578d91bf416fa6a3f8e31aece 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -148,11 +148,21 @@ public class Category {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index e40c03e0590ede629cda5baab8ccf8de418591f7..c8d31ad5203acf9e212ec79c8427700b41ed3b77 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -26,8 +26,8 @@ import org.openapitools.client.model.Category;
 import org.openapitools.client.model.Tag;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -330,11 +330,21 @@ public class Pet {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `category` to the URL query string
     if (getCategory() != null) {
@@ -343,7 +353,12 @@ public class Pet {
     // add `photoUrls` to the URL query string
     if (getPhotoUrls() != null) {
       for (int i = 0; i < getPhotoUrls().size(); i++) {
-        joiner.add(String.format("%s[photoUrls][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getPhotoUrls().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[photoUrls][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getPhotoUrls().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `tags` to the URL query string
@@ -356,7 +371,12 @@ public class Pet {
     }
     // add `status` to the URL query string
     if (getStatus() != null) {
-      joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
index a384b7478239d55863604ceb3d18c6d6393e57f6..b25c5ee7eddec0e0a07f3d0bb9badfac773bc983 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -148,11 +148,21 @@ public class Tag {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index f698d9b09395c6c0009ad92559a5d0b0995a9381..24a20a9f2c7b231c463b6d8eeb25bc238febb9ba 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -24,8 +24,8 @@ import java.util.ArrayList;
 import java.util.List;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -128,7 +128,12 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
     // add `values` to the URL query string
     if (getValues() != null) {
       for (int i = 0; i < getValues().size(); i++) {
-        joiner.add(String.format("%s[values][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getValues().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[values][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getValues().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
index 3648b19c84b7749c29d489bd58a01a76fb65e0f5..b33350054484ba0bc194bb2b2e2c3ca66dda53f2 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Bird {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/BirdAndCategory.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/BirdAndCategory.java
index f5fc68e09fced9e604906bdb45874abc5cc332a3..ead784d736be739a40949ffd7820e75e7d31449d 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/BirdAndCategory.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/BirdAndCategory.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -200,7 +200,6 @@ public class BirdAndCategory {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
index 2fad2a1c1a57e92e99de5a88554587129c5e86c9..4756fae367e7dca53de1bf34d79dc8660a11a675 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Category {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
index 2b290884e3de70786ef707a8a5a6a5512dd8defa..04bb4ce72dc941627bd03fbc2a28650c23f58f50 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -316,7 +316,6 @@ public class Pet {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
index 83db4ff69cccdfff5f04ffa661b8087c1ab977ad..55d9a7487e7be558162be1eb4178d0af23824de8 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Tag {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 82bc3671c26a6a463afcc35243cad12e2f3a2487..d64cccbf0eee6cb43fe2ae59aa5a3710addd5787 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -117,7 +117,6 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 425e819a70d66f13d464c36698ce215dea557bbe..c39269a9e0eeaddc0183ba03921be8545a9aabfc 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -24,8 +24,8 @@ import java.util.HashMap;
 import java.util.Map;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -167,13 +167,23 @@ public class AdditionalPropertiesClass {
     // add `map_property` to the URL query string
     if (getMapProperty() != null) {
       for (String _key : getMapProperty().keySet()) {
-        joiner.add(String.format("%s[map_property][%s]=%s", prefix, getMapProperty().get(_key), URLEncoder.encode(String.valueOf(getMapProperty().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[map_property][%s]=%s", prefix, getMapProperty().get(_key), URLEncoder.encode(String.valueOf(getMapProperty().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `map_of_map_property` to the URL query string
     if (getMapOfMapProperty() != null) {
       for (String _key : getMapOfMapProperty().keySet()) {
-        joiner.add(String.format("%s[map_of_map_property][%s]=%s", prefix, getMapOfMapProperty().get(_key), URLEncoder.encode(String.valueOf(getMapOfMapProperty().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[map_of_map_property][%s]=%s", prefix, getMapOfMapProperty().get(_key), URLEncoder.encode(String.valueOf(getMapOfMapProperty().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 945d1b87ff3892621be8f9ecd375c5d0340066ed..8015cad643da856cb5101c318cd0a03ee965bdb2 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.SingleRefType;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -149,7 +149,12 @@ public class AllOfWithSingleRef {
     StringJoiner joiner = new StringJoiner("&");
     // add `username` to the URL query string
     if (getUsername() != null) {
-      joiner.add(String.format("%s[username]=%s", prefix, URLEncoder.encode(String.valueOf(getUsername()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[username]=%s", prefix, URLEncoder.encode(String.valueOf(getUsername()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `SingleRefType` to the URL query string
     if (getSingleRefType() != null) {
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
index fc23e9d0ed880e6a05c94f408635bbe3a9f91ded..3b0ed2dc49f328355e6763be9cfddc93bc3c6462 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
@@ -27,8 +27,8 @@ import org.openapitools.client.model.Cat;
 import org.openapitools.client.model.Dog;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -163,11 +163,21 @@ public class Animal {
     StringJoiner joiner = new StringJoiner("&");
     // add `className` to the URL query string
     if (getClassName() != null) {
-      joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `color` to the URL query string
     if (getColor() != null) {
-      joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index b452e5243e14fed7e7004462b9bd2cd5c4a9e4c6..ec22395e8f34b89d5fdcbd38109d63b77fe6c47e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -25,8 +25,8 @@ import java.util.ArrayList;
 import java.util.List;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -129,7 +129,12 @@ public class ArrayOfArrayOfNumberOnly {
     if (getArrayArrayNumber() != null) {
       for (int i = 0; i < getArrayArrayNumber().size(); i++) {
         if (getArrayArrayNumber().get(i) != null) {
-          joiner.add(String.format("%s[ArrayArrayNumber][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayNumber().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          try {
+            joiner.add(String.format("%s[ArrayArrayNumber][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayNumber().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+          } catch (UnsupportedEncodingException e) {
+            // Should never happen, UTF-8 is always supported
+            throw new RuntimeException(e);
+          }
         }
       }
     }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index b9a3e131a2bad30084d5c2a5bae252833c079fb8..cb11290224faac48c2cd0152e109224d470fe0be 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -25,8 +25,8 @@ import java.util.ArrayList;
 import java.util.List;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -129,7 +129,12 @@ public class ArrayOfNumberOnly {
     if (getArrayNumber() != null) {
       for (int i = 0; i < getArrayNumber().size(); i++) {
         if (getArrayNumber().get(i) != null) {
-          joiner.add(String.format("%s[ArrayNumber][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayNumber().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          try {
+            joiner.add(String.format("%s[ArrayNumber][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayNumber().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+          } catch (UnsupportedEncodingException e) {
+            // Should never happen, UTF-8 is always supported
+            throw new RuntimeException(e);
+          }
         }
       }
     }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
index 55e2232949dbe8b1d4c96a627db6db023362510a..00d928bb2a15db56aeb5cb70128714538a63853b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -25,8 +25,8 @@ import java.util.List;
 import org.openapitools.client.model.ReadOnlyFirst;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -208,20 +208,35 @@ public class ArrayTest {
     // add `array_of_string` to the URL query string
     if (getArrayOfString() != null) {
       for (int i = 0; i < getArrayOfString().size(); i++) {
-        joiner.add(String.format("%s[array_of_string][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayOfString().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_of_string][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayOfString().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `array_array_of_integer` to the URL query string
     if (getArrayArrayOfInteger() != null) {
       for (int i = 0; i < getArrayArrayOfInteger().size(); i++) {
-        joiner.add(String.format("%s[array_array_of_integer][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayOfInteger().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_array_of_integer][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayOfInteger().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `array_array_of_model` to the URL query string
     if (getArrayArrayOfModel() != null) {
       for (int i = 0; i < getArrayArrayOfModel().size(); i++) {
         if (getArrayArrayOfModel().get(i) != null) {
-          joiner.add(String.format("%s[array_array_of_model][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayOfModel().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          try {
+            joiner.add(String.format("%s[array_array_of_model][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayArrayOfModel().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+          } catch (UnsupportedEncodingException e) {
+            // Should never happen, UTF-8 is always supported
+            throw new RuntimeException(e);
+          }
         }
       }
     }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
index 210bc067e287cdee73372c138f3c284324754eb4..d4f91eba427c8a7ff8886a40222fffcbe83159a1 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -276,27 +276,57 @@ public class Capitalization {
     StringJoiner joiner = new StringJoiner("&");
     // add `smallCamel` to the URL query string
     if (getSmallCamel() != null) {
-      joiner.add(String.format("%s[smallCamel]=%s", prefix, URLEncoder.encode(String.valueOf(getSmallCamel()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[smallCamel]=%s", prefix, URLEncoder.encode(String.valueOf(getSmallCamel()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `CapitalCamel` to the URL query string
     if (getCapitalCamel() != null) {
-      joiner.add(String.format("%s[CapitalCamel]=%s", prefix, URLEncoder.encode(String.valueOf(getCapitalCamel()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[CapitalCamel]=%s", prefix, URLEncoder.encode(String.valueOf(getCapitalCamel()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `small_Snake` to the URL query string
     if (getSmallSnake() != null) {
-      joiner.add(String.format("%s[small_Snake]=%s", prefix, URLEncoder.encode(String.valueOf(getSmallSnake()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[small_Snake]=%s", prefix, URLEncoder.encode(String.valueOf(getSmallSnake()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `Capital_Snake` to the URL query string
     if (getCapitalSnake() != null) {
-      joiner.add(String.format("%s[Capital_Snake]=%s", prefix, URLEncoder.encode(String.valueOf(getCapitalSnake()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[Capital_Snake]=%s", prefix, URLEncoder.encode(String.valueOf(getCapitalSnake()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `SCA_ETH_Flow_Points` to the URL query string
     if (getScAETHFlowPoints() != null) {
-      joiner.add(String.format("%s[SCA_ETH_Flow_Points]=%s", prefix, URLEncoder.encode(String.valueOf(getScAETHFlowPoints()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[SCA_ETH_Flow_Points]=%s", prefix, URLEncoder.encode(String.valueOf(getScAETHFlowPoints()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `ATT_NAME` to the URL query string
     if (getATTNAME() != null) {
-      joiner.add(String.format("%s[ATT_NAME]=%s", prefix, URLEncoder.encode(String.valueOf(getATTNAME()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[ATT_NAME]=%s", prefix, URLEncoder.encode(String.valueOf(getATTNAME()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
index 9f5dacc290f28abf5272cb640c930a5b29c27192..56afb5778294f5c54efdf2b77d34261a8c1f08d6 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
@@ -26,8 +26,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.Animal;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -129,15 +129,30 @@ public class Cat extends Animal {
     StringJoiner joiner = new StringJoiner("&");
     // add `className` to the URL query string
     if (getClassName() != null) {
-      joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `color` to the URL query string
     if (getColor() != null) {
-      joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `declawed` to the URL query string
     if (getDeclawed() != null) {
-      joiner.add(String.format("%s[declawed]=%s", prefix, URLEncoder.encode(String.valueOf(getDeclawed()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[declawed]=%s", prefix, URLEncoder.encode(String.valueOf(getDeclawed()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/CatAllOf.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/CatAllOf.java
index 66fd0c495323a932aec98d6803ebd40f6f13093e..28689452bb386724039458f3fdaa7fad8a05833c 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/CatAllOf.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/CatAllOf.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class CatAllOf {
     StringJoiner joiner = new StringJoiner("&");
     // add `declawed` to the URL query string
     if (getDeclawed() != null) {
-      joiner.add(String.format("%s[declawed]=%s", prefix, URLEncoder.encode(String.valueOf(getDeclawed()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[declawed]=%s", prefix, URLEncoder.encode(String.valueOf(getDeclawed()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
index f0c9d8708b29054f9758231c0bdedf1aa3f5f57c..00229270d48ff573843fac7def1ecfba1539b85d 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -148,11 +148,21 @@ public class Category {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
index 9d9f1c3024154d61d28242cad3c3a1fdcdbbc250..c1776d1f789e2758a8d99457ad986318e7c8841b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -116,7 +116,12 @@ public class ClassModel {
     StringJoiner joiner = new StringJoiner("&");
     // add `_class` to the URL query string
     if (getPropertyClass() != null) {
-      joiner.add(String.format("%s[_class]=%s", prefix, URLEncoder.encode(String.valueOf(getPropertyClass()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[_class]=%s", prefix, URLEncoder.encode(String.valueOf(getPropertyClass()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
index 3787a7ff15a2872b894578f9453d78b47a6884d9..a3f5e9913be62c7d4b766b32a543facbb8f45406 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -116,7 +116,12 @@ public class Client {
     StringJoiner joiner = new StringJoiner("&");
     // add `client` to the URL query string
     if (getClient() != null) {
-      joiner.add(String.format("%s[client]=%s", prefix, URLEncoder.encode(String.valueOf(getClient()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[client]=%s", prefix, URLEncoder.encode(String.valueOf(getClient()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 1fc03cfc9fc6820d2770be00f8e9686dd7c800eb..2862dfaba7941894c9d81a0d9f69a2cf507ffd50 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -118,7 +118,12 @@ public class DeprecatedObject {
     StringJoiner joiner = new StringJoiner("&");
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
index fbc9f2b44e1781b4e2700e6939df66dbfca8277e..2bf6beacf197995bd56ef7717be816a188eb43ae 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
@@ -26,8 +26,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.Animal;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -129,15 +129,30 @@ public class Dog extends Animal {
     StringJoiner joiner = new StringJoiner("&");
     // add `className` to the URL query string
     if (getClassName() != null) {
-      joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[className]=%s", prefix, URLEncoder.encode(String.valueOf(getClassName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `color` to the URL query string
     if (getColor() != null) {
-      joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[color]=%s", prefix, URLEncoder.encode(String.valueOf(getColor()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `breed` to the URL query string
     if (getBreed() != null) {
-      joiner.add(String.format("%s[breed]=%s", prefix, URLEncoder.encode(String.valueOf(getBreed()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[breed]=%s", prefix, URLEncoder.encode(String.valueOf(getBreed()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DogAllOf.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DogAllOf.java
index 98bc32fd082c8653d6ad2f87bb545f566f77e989..4cc2b03f61f4a1d583c9e65a0f4de0a4510a7ba5 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DogAllOf.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DogAllOf.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class DogAllOf {
     StringJoiner joiner = new StringJoiner("&");
     // add `breed` to the URL query string
     if (getBreed() != null) {
-      joiner.add(String.format("%s[breed]=%s", prefix, URLEncoder.encode(String.valueOf(getBreed()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[breed]=%s", prefix, URLEncoder.encode(String.valueOf(getBreed()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
index cd1f9e1671361581e9678b57a00a73dbc27f4be2..8f73270abba49cce2a6cf6cf94d751b5fb8c683d 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -24,8 +24,8 @@ import java.util.ArrayList;
 import java.util.List;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -228,12 +228,22 @@ public class EnumArrays {
     StringJoiner joiner = new StringJoiner("&");
     // add `just_symbol` to the URL query string
     if (getJustSymbol() != null) {
-      joiner.add(String.format("%s[just_symbol]=%s", prefix, URLEncoder.encode(String.valueOf(getJustSymbol()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[just_symbol]=%s", prefix, URLEncoder.encode(String.valueOf(getJustSymbol()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `array_enum` to the URL query string
     if (getArrayEnum() != null) {
       for (int i = 0; i < getArrayEnum().size(); i++) {
-        joiner.add(String.format("%s[array_enum][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayEnum().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_enum][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayEnum().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumClass.java
index 65c3d66c24673d1cfb600dc53cd73820e05fcf7d..4d38ed92745c29bd57a02f6af8ed86fa31f287bc 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumClass.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
index b0dec386d8a1ec5d7c05a824c421ceae7ffcc066..9678f9530f6f2d03a462e253411d774f5a848609 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -30,8 +30,8 @@ import org.openapitools.jackson.nullable.JsonNullable;
 import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -512,35 +512,75 @@ public class EnumTest {
     StringJoiner joiner = new StringJoiner("&");
     // add `enum_string` to the URL query string
     if (getEnumString() != null) {
-      joiner.add(String.format("%s[enum_string]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumString()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[enum_string]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumString()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `enum_string_required` to the URL query string
     if (getEnumStringRequired() != null) {
-      joiner.add(String.format("%s[enum_string_required]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumStringRequired()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[enum_string_required]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumStringRequired()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `enum_integer` to the URL query string
     if (getEnumInteger() != null) {
-      joiner.add(String.format("%s[enum_integer]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumInteger()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[enum_integer]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumInteger()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `enum_number` to the URL query string
     if (getEnumNumber() != null) {
-      joiner.add(String.format("%s[enum_number]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumNumber()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[enum_number]=%s", prefix, URLEncoder.encode(String.valueOf(getEnumNumber()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `outerEnum` to the URL query string
     if (getOuterEnum() != null) {
-      joiner.add(String.format("%s[outerEnum]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnum()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[outerEnum]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnum()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `outerEnumInteger` to the URL query string
     if (getOuterEnumInteger() != null) {
-      joiner.add(String.format("%s[outerEnumInteger]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumInteger()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[outerEnumInteger]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumInteger()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `outerEnumDefaultValue` to the URL query string
     if (getOuterEnumDefaultValue() != null) {
-      joiner.add(String.format("%s[outerEnumDefaultValue]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumDefaultValue()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[outerEnumDefaultValue]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumDefaultValue()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `outerEnumIntegerDefaultValue` to the URL query string
     if (getOuterEnumIntegerDefaultValue() != null) {
-      joiner.add(String.format("%s[outerEnumIntegerDefaultValue]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumIntegerDefaultValue()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[outerEnumIntegerDefaultValue]=%s", prefix, URLEncoder.encode(String.valueOf(getOuterEnumIntegerDefaultValue()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index a46194194306cbea506d40dc173d5858a24d1b61..1aac2884f26526f183606f3dae7e183a1c260dbb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -25,8 +25,8 @@ import java.util.List;
 import org.openapitools.client.model.ModelFile;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
index e4bb9166b93936f48c831c9de92f1b20b21c7ba9..5ef461789f4ad13600c9a86dec1df451dc761587 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -116,7 +116,12 @@ public class Foo {
     StringJoiner joiner = new StringJoiner("&");
     // add `bar` to the URL query string
     if (getBar() != null) {
-      joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 466e071912e401ff0f7cc3e9fc302d5916853945..665b8f541fa571ebc5ebad73123ba1b7c3e98324 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.Foo;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
index 173e4ad8e982685f3189aff58650a9d2dd1d14d1..f0d6ecaea2a6e514251b3b3fb8d2861891e976fb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -27,8 +27,8 @@ import java.time.OffsetDateTime;
 import java.util.UUID;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -612,67 +612,147 @@ public class FormatTest {
     StringJoiner joiner = new StringJoiner("&");
     // add `integer` to the URL query string
     if (getInteger() != null) {
-      joiner.add(String.format("%s[integer]=%s", prefix, URLEncoder.encode(String.valueOf(getInteger()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[integer]=%s", prefix, URLEncoder.encode(String.valueOf(getInteger()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `int32` to the URL query string
     if (getInt32() != null) {
-      joiner.add(String.format("%s[int32]=%s", prefix, URLEncoder.encode(String.valueOf(getInt32()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[int32]=%s", prefix, URLEncoder.encode(String.valueOf(getInt32()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `int64` to the URL query string
     if (getInt64() != null) {
-      joiner.add(String.format("%s[int64]=%s", prefix, URLEncoder.encode(String.valueOf(getInt64()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[int64]=%s", prefix, URLEncoder.encode(String.valueOf(getInt64()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `number` to the URL query string
     if (getNumber() != null) {
-      joiner.add(String.format("%s[number]=%s", prefix, URLEncoder.encode(String.valueOf(getNumber()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[number]=%s", prefix, URLEncoder.encode(String.valueOf(getNumber()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `float` to the URL query string
     if (getFloat() != null) {
-      joiner.add(String.format("%s[float]=%s", prefix, URLEncoder.encode(String.valueOf(getFloat()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[float]=%s", prefix, URLEncoder.encode(String.valueOf(getFloat()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `double` to the URL query string
     if (getDouble() != null) {
-      joiner.add(String.format("%s[double]=%s", prefix, URLEncoder.encode(String.valueOf(getDouble()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[double]=%s", prefix, URLEncoder.encode(String.valueOf(getDouble()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `decimal` to the URL query string
     if (getDecimal() != null) {
-      joiner.add(String.format("%s[decimal]=%s", prefix, URLEncoder.encode(String.valueOf(getDecimal()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[decimal]=%s", prefix, URLEncoder.encode(String.valueOf(getDecimal()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `string` to the URL query string
     if (getString() != null) {
-      joiner.add(String.format("%s[string]=%s", prefix, URLEncoder.encode(String.valueOf(getString()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[string]=%s", prefix, URLEncoder.encode(String.valueOf(getString()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `byte` to the URL query string
     if (getByte() != null) {
-      joiner.add(String.format("%s[byte]=%s", prefix, URLEncoder.encode(String.valueOf(getByte()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[byte]=%s", prefix, URLEncoder.encode(String.valueOf(getByte()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `binary` to the URL query string
     if (getBinary() != null) {
-      joiner.add(String.format("%s[binary]=%s", prefix, URLEncoder.encode(String.valueOf(getBinary()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[binary]=%s", prefix, URLEncoder.encode(String.valueOf(getBinary()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `date` to the URL query string
     if (getDate() != null) {
-      joiner.add(String.format("%s[date]=%s", prefix, URLEncoder.encode(String.valueOf(getDate()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[date]=%s", prefix, URLEncoder.encode(String.valueOf(getDate()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `dateTime` to the URL query string
     if (getDateTime() != null) {
-      joiner.add(String.format("%s[dateTime]=%s", prefix, URLEncoder.encode(String.valueOf(getDateTime()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[dateTime]=%s", prefix, URLEncoder.encode(String.valueOf(getDateTime()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `uuid` to the URL query string
     if (getUuid() != null) {
-      joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `password` to the URL query string
     if (getPassword() != null) {
-      joiner.add(String.format("%s[password]=%s", prefix, URLEncoder.encode(String.valueOf(getPassword()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[password]=%s", prefix, URLEncoder.encode(String.valueOf(getPassword()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `pattern_with_digits` to the URL query string
     if (getPatternWithDigits() != null) {
-      joiner.add(String.format("%s[pattern_with_digits]=%s", prefix, URLEncoder.encode(String.valueOf(getPatternWithDigits()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[pattern_with_digits]=%s", prefix, URLEncoder.encode(String.valueOf(getPatternWithDigits()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `pattern_with_digits_and_delimiter` to the URL query string
     if (getPatternWithDigitsAndDelimiter() != null) {
-      joiner.add(String.format("%s[pattern_with_digits_and_delimiter]=%s", prefix, URLEncoder.encode(String.valueOf(getPatternWithDigitsAndDelimiter()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[pattern_with_digits_and_delimiter]=%s", prefix, URLEncoder.encode(String.valueOf(getPatternWithDigitsAndDelimiter()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 9d681c98ae94bc608ea35a1ab41b87bd41c4ee7f..7817bae3937cd84c850d4cc2d51e5c3bc3e37f73 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -137,11 +137,21 @@ public class HasOnlyReadOnly {
     StringJoiner joiner = new StringJoiner("&");
     // add `bar` to the URL query string
     if (getBar() != null) {
-      joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `foo` to the URL query string
     if (getFoo() != null) {
-      joiner.add(String.format("%s[foo]=%s", prefix, URLEncoder.encode(String.valueOf(getFoo()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[foo]=%s", prefix, URLEncoder.encode(String.valueOf(getFoo()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 52d50c680141f11197b079532cc72e5041b25051..3fbb2d2cac43009475ac33b7941fe6cb5d4c7ab1 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -26,8 +26,8 @@ import org.openapitools.jackson.nullable.JsonNullable;
 import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -139,7 +139,12 @@ public class HealthCheckResult {
     StringJoiner joiner = new StringJoiner("&");
     // add `NullableMessage` to the URL query string
     if (getNullableMessage() != null) {
-      joiner.add(String.format("%s[NullableMessage]=%s", prefix, URLEncoder.encode(String.valueOf(getNullableMessage()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[NullableMessage]=%s", prefix, URLEncoder.encode(String.valueOf(getNullableMessage()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
index 3c86bfee6b1928031059f8d6bcde16cf399e7dbc..bfe6dc90b068c735c28e5ea8957929ea818a1a72 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
@@ -24,8 +24,8 @@ import java.util.HashMap;
 import java.util.Map;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -282,25 +282,45 @@ public class MapTest {
     // add `map_map_of_string` to the URL query string
     if (getMapMapOfString() != null) {
       for (String _key : getMapMapOfString().keySet()) {
-        joiner.add(String.format("%s[map_map_of_string][%s]=%s", prefix, getMapMapOfString().get(_key), URLEncoder.encode(String.valueOf(getMapMapOfString().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[map_map_of_string][%s]=%s", prefix, getMapMapOfString().get(_key), URLEncoder.encode(String.valueOf(getMapMapOfString().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `map_of_enum_string` to the URL query string
     if (getMapOfEnumString() != null) {
       for (String _key : getMapOfEnumString().keySet()) {
-        joiner.add(String.format("%s[map_of_enum_string][%s]=%s", prefix, getMapOfEnumString().get(_key), URLEncoder.encode(String.valueOf(getMapOfEnumString().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[map_of_enum_string][%s]=%s", prefix, getMapOfEnumString().get(_key), URLEncoder.encode(String.valueOf(getMapOfEnumString().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `direct_map` to the URL query string
     if (getDirectMap() != null) {
       for (String _key : getDirectMap().keySet()) {
-        joiner.add(String.format("%s[direct_map][%s]=%s", prefix, getDirectMap().get(_key), URLEncoder.encode(String.valueOf(getDirectMap().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[direct_map][%s]=%s", prefix, getDirectMap().get(_key), URLEncoder.encode(String.valueOf(getDirectMap().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `indirect_map` to the URL query string
     if (getIndirectMap() != null) {
       for (String _key : getIndirectMap().keySet()) {
-        joiner.add(String.format("%s[indirect_map][%s]=%s", prefix, getIndirectMap().get(_key), URLEncoder.encode(String.valueOf(getIndirectMap().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[indirect_map][%s]=%s", prefix, getIndirectMap().get(_key), URLEncoder.encode(String.valueOf(getIndirectMap().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5ba1f6bbd654b2e7e70ba93c9fa63d27d424b3e5..6112c4480590324f41ebfa68261061f5e30760fb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -27,8 +27,8 @@ import java.util.UUID;
 import org.openapitools.client.model.Animal;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -193,11 +193,21 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     StringJoiner joiner = new StringJoiner("&");
     // add `uuid` to the URL query string
     if (getUuid() != null) {
-      joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `dateTime` to the URL query string
     if (getDateTime() != null) {
-      joiner.add(String.format("%s[dateTime]=%s", prefix, URLEncoder.encode(String.valueOf(getDateTime()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[dateTime]=%s", prefix, URLEncoder.encode(String.valueOf(getDateTime()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `map` to the URL query string
     if (getMap() != null) {
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
index 722cb873dc6098c5fd1e3a676e0abbe183d3302a..729cf9adaec67d20c812f99e5d84ff5878a1f36e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -149,11 +149,21 @@ public class Model200Response {
     StringJoiner joiner = new StringJoiner("&");
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `class` to the URL query string
     if (getPropertyClass() != null) {
-      joiner.add(String.format("%s[class]=%s", prefix, URLEncoder.encode(String.valueOf(getPropertyClass()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[class]=%s", prefix, URLEncoder.encode(String.valueOf(getPropertyClass()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index cf824b889919e6dd27e009caf54f3ef68655ec5a..c7ed38589a5c4e78ab8e15b68f7abf419e7aa609 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -181,15 +181,30 @@ public class ModelApiResponse {
     StringJoiner joiner = new StringJoiner("&");
     // add `code` to the URL query string
     if (getCode() != null) {
-      joiner.add(String.format("%s[code]=%s", prefix, URLEncoder.encode(String.valueOf(getCode()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[code]=%s", prefix, URLEncoder.encode(String.valueOf(getCode()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `type` to the URL query string
     if (getType() != null) {
-      joiner.add(String.format("%s[type]=%s", prefix, URLEncoder.encode(String.valueOf(getType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[type]=%s", prefix, URLEncoder.encode(String.valueOf(getType()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `message` to the URL query string
     if (getMessage() != null) {
-      joiner.add(String.format("%s[message]=%s", prefix, URLEncoder.encode(String.valueOf(getMessage()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[message]=%s", prefix, URLEncoder.encode(String.valueOf(getMessage()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
index ab77aa99ecc650844bfa51ebc1fa8522098e8868..e42a5aec6a17736ec98799aceb0c07dcd579de50 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class ModelFile {
     StringJoiner joiner = new StringJoiner("&");
     // add `sourceURI` to the URL query string
     if (getSourceURI() != null) {
-      joiner.add(String.format("%s[sourceURI]=%s", prefix, URLEncoder.encode(String.valueOf(getSourceURI()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[sourceURI]=%s", prefix, URLEncoder.encode(String.valueOf(getSourceURI()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
index bdb527caa4544ebc786bdc1974224c57a77f4f1b..d0a8535aea35b553fb1b7595956583ea93798f2e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class ModelList {
     StringJoiner joiner = new StringJoiner("&");
     // add `123-list` to the URL query string
     if (get123list() != null) {
-      joiner.add(String.format("%s[123-list]=%s", prefix, URLEncoder.encode(String.valueOf(get123list()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[123-list]=%s", prefix, URLEncoder.encode(String.valueOf(get123list()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
index 66a7f0e13bf7e1513bc0d0f5a6981bbf0cd04a65..47c16f202684d54fa85b525d6d7c4fa7fb269146 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class ModelReturn {
     StringJoiner joiner = new StringJoiner("&");
     // add `return` to the URL query string
     if (getReturn() != null) {
-      joiner.add(String.format("%s[return]=%s", prefix, URLEncoder.encode(String.valueOf(getReturn()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[return]=%s", prefix, URLEncoder.encode(String.valueOf(getReturn()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
index 6df5ee850936e16057e39acbd5e7a02357926b85..d3a9dd256abce08869e73bf68864c9c232d0c479 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -200,19 +200,39 @@ public class Name {
     StringJoiner joiner = new StringJoiner("&");
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `snake_case` to the URL query string
     if (getSnakeCase() != null) {
-      joiner.add(String.format("%s[snake_case]=%s", prefix, URLEncoder.encode(String.valueOf(getSnakeCase()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[snake_case]=%s", prefix, URLEncoder.encode(String.valueOf(getSnakeCase()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `property` to the URL query string
     if (getProperty() != null) {
-      joiner.add(String.format("%s[property]=%s", prefix, URLEncoder.encode(String.valueOf(getProperty()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[property]=%s", prefix, URLEncoder.encode(String.valueOf(getProperty()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `123Number` to the URL query string
     if (get123number() != null) {
-      joiner.add(String.format("%s[123Number]=%s", prefix, URLEncoder.encode(String.valueOf(get123number()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[123Number]=%s", prefix, URLEncoder.encode(String.valueOf(get123number()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
index cf9e746fa4ba2f9c56396815aadc33b85a97bcf0..604f5f9e27d8fa125b1b405ca798a11ff840580b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -33,8 +33,8 @@ import org.openapitools.jackson.nullable.JsonNullable;
 import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -637,62 +637,122 @@ public class NullableClass extends HashMap<String, Object> {
     StringJoiner joiner = new StringJoiner("&");
     // add `integer_prop` to the URL query string
     if (getIntegerProp() != null) {
-      joiner.add(String.format("%s[integer_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getIntegerProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[integer_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getIntegerProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `number_prop` to the URL query string
     if (getNumberProp() != null) {
-      joiner.add(String.format("%s[number_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getNumberProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[number_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getNumberProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `boolean_prop` to the URL query string
     if (getBooleanProp() != null) {
-      joiner.add(String.format("%s[boolean_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getBooleanProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[boolean_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getBooleanProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `string_prop` to the URL query string
     if (getStringProp() != null) {
-      joiner.add(String.format("%s[string_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getStringProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[string_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getStringProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `date_prop` to the URL query string
     if (getDateProp() != null) {
-      joiner.add(String.format("%s[date_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getDateProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[date_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getDateProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `datetime_prop` to the URL query string
     if (getDatetimeProp() != null) {
-      joiner.add(String.format("%s[datetime_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getDatetimeProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[datetime_prop]=%s", prefix, URLEncoder.encode(String.valueOf(getDatetimeProp()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `array_nullable_prop` to the URL query string
     if (getArrayNullableProp() != null) {
       for (int i = 0; i < getArrayNullableProp().size(); i++) {
-        joiner.add(String.format("%s[array_nullable_prop][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayNullableProp().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_nullable_prop][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayNullableProp().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `array_and_items_nullable_prop` to the URL query string
     if (getArrayAndItemsNullableProp() != null) {
       for (int i = 0; i < getArrayAndItemsNullableProp().size(); i++) {
-        joiner.add(String.format("%s[array_and_items_nullable_prop][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayAndItemsNullableProp().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_and_items_nullable_prop][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayAndItemsNullableProp().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `array_items_nullable` to the URL query string
     if (getArrayItemsNullable() != null) {
       for (int i = 0; i < getArrayItemsNullable().size(); i++) {
-        joiner.add(String.format("%s[array_items_nullable][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayItemsNullable().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[array_items_nullable][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getArrayItemsNullable().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `object_nullable_prop` to the URL query string
     if (getObjectNullableProp() != null) {
       for (String _key : getObjectNullableProp().keySet()) {
-        joiner.add(String.format("%s[object_nullable_prop][%s]=%s", prefix, getObjectNullableProp().get(_key), URLEncoder.encode(String.valueOf(getObjectNullableProp().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[object_nullable_prop][%s]=%s", prefix, getObjectNullableProp().get(_key), URLEncoder.encode(String.valueOf(getObjectNullableProp().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `object_and_items_nullable_prop` to the URL query string
     if (getObjectAndItemsNullableProp() != null) {
       for (String _key : getObjectAndItemsNullableProp().keySet()) {
-        joiner.add(String.format("%s[object_and_items_nullable_prop][%s]=%s", prefix, getObjectAndItemsNullableProp().get(_key), URLEncoder.encode(String.valueOf(getObjectAndItemsNullableProp().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[object_and_items_nullable_prop][%s]=%s", prefix, getObjectAndItemsNullableProp().get(_key), URLEncoder.encode(String.valueOf(getObjectAndItemsNullableProp().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     // add `object_items_nullable` to the URL query string
     if (getObjectItemsNullable() != null) {
       for (String _key : getObjectItemsNullable().keySet()) {
-        joiner.add(String.format("%s[object_items_nullable][%s]=%s", prefix, getObjectItemsNullable().get(_key), URLEncoder.encode(String.valueOf(getObjectItemsNullable().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[object_items_nullable][%s]=%s", prefix, getObjectItemsNullable().get(_key), URLEncoder.encode(String.valueOf(getObjectItemsNullable().get(_key)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
index bf123446a6a76b884b156c823b07a7f5de04ecb9..25141ccc633b88190fa7894b76137741f8b7e152 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import java.math.BigDecimal;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class NumberOnly {
     StringJoiner joiner = new StringJoiner("&");
     // add `JustNumber` to the URL query string
     if (getJustNumber() != null) {
-      joiner.add(String.format("%s[JustNumber]=%s", prefix, URLEncoder.encode(String.valueOf(getJustNumber()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[JustNumber]=%s", prefix, URLEncoder.encode(String.valueOf(getJustNumber()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index e4b0f0eaac4656a6f1ec5b3fe3c9e3ee7f4450c1..6b815e639ab4bd0b97687672c171ee4186ec73ab 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -26,8 +26,8 @@ import java.util.List;
 import org.openapitools.client.model.DeprecatedObject;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -230,11 +230,21 @@ public class ObjectWithDeprecatedFields {
     StringJoiner joiner = new StringJoiner("&");
     // add `uuid` to the URL query string
     if (getUuid() != null) {
-      joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[uuid]=%s", prefix, URLEncoder.encode(String.valueOf(getUuid()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `deprecatedRef` to the URL query string
     if (getDeprecatedRef() != null) {
@@ -243,7 +253,12 @@ public class ObjectWithDeprecatedFields {
     // add `bars` to the URL query string
     if (getBars() != null) {
       for (int i = 0; i < getBars().size(); i++) {
-        joiner.add(String.format("%s[bars][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getBars().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[bars][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(getBars().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
     }
     return joiner.toString();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
index 16ba5994a5407204bc5d44d69c1a8eda4d2566fe..7619ef6103dfa37b16212751997aff0430d97690 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import java.time.OffsetDateTime;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -314,27 +314,57 @@ public class Order {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `petId` to the URL query string
     if (getPetId() != null) {
-      joiner.add(String.format("%s[petId]=%s", prefix, URLEncoder.encode(String.valueOf(getPetId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[petId]=%s", prefix, URLEncoder.encode(String.valueOf(getPetId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `quantity` to the URL query string
     if (getQuantity() != null) {
-      joiner.add(String.format("%s[quantity]=%s", prefix, URLEncoder.encode(String.valueOf(getQuantity()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[quantity]=%s", prefix, URLEncoder.encode(String.valueOf(getQuantity()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `shipDate` to the URL query string
     if (getShipDate() != null) {
-      joiner.add(String.format("%s[shipDate]=%s", prefix, URLEncoder.encode(String.valueOf(getShipDate()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[shipDate]=%s", prefix, URLEncoder.encode(String.valueOf(getShipDate()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `status` to the URL query string
     if (getStatus() != null) {
-      joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `complete` to the URL query string
     if (getComplete() != null) {
-      joiner.add(String.format("%s[complete]=%s", prefix, URLEncoder.encode(String.valueOf(getComplete()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[complete]=%s", prefix, URLEncoder.encode(String.valueOf(getComplete()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
index 42f74aa84aa0d063827418df3502579e91cb0319..72f76ff87ea7bea10c79aa530c3923a79e27cb9f 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import java.math.BigDecimal;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -181,15 +181,30 @@ public class OuterComposite {
     StringJoiner joiner = new StringJoiner("&");
     // add `my_number` to the URL query string
     if (getMyNumber() != null) {
-      joiner.add(String.format("%s[my_number]=%s", prefix, URLEncoder.encode(String.valueOf(getMyNumber()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[my_number]=%s", prefix, URLEncoder.encode(String.valueOf(getMyNumber()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `my_string` to the URL query string
     if (getMyString() != null) {
-      joiner.add(String.format("%s[my_string]=%s", prefix, URLEncoder.encode(String.valueOf(getMyString()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[my_string]=%s", prefix, URLEncoder.encode(String.valueOf(getMyString()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `my_boolean` to the URL query string
     if (getMyBoolean() != null) {
-      joiner.add(String.format("%s[my_boolean]=%s", prefix, URLEncoder.encode(String.valueOf(getMyBoolean()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[my_boolean]=%s", prefix, URLEncoder.encode(String.valueOf(getMyBoolean()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnum.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnum.java
index bce6290bb04bf776c7c225a801f1c628a736fe20..0926d83a5e49623ca06c06fc10b4267621cdfe64 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnum.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnum.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
index 95e5e2491b2361e22739c3f034ac9ac33a0757f0..cd8dc664456327ceab949b92deec204e3a049fbe 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumInteger.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
index 0f5cadd5454e793c4555527393e2be80a04a6c56..298e097de0180c69360282f9c88375f558f2e02a 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
index b093f10add44f9b49f1bb641b9f482e7b33dcdad..06e64346381e65f6a50cde517b48e772f4ad1ff2 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 1b653aa4bbb7cf24679375412a39dea263f22bc8..0e5ef5e2cefbf841f0069cff1ec9b0056b7cd815 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -23,8 +23,8 @@ import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.OuterEnumInteger;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class OuterObjectWithEnumProperty {
     StringJoiner joiner = new StringJoiner("&");
     // add `value` to the URL query string
     if (getValue() != null) {
-      joiner.add(String.format("%s[value]=%s", prefix, URLEncoder.encode(String.valueOf(getValue()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[value]=%s", prefix, URLEncoder.encode(String.valueOf(getValue()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index b24c8abb9a3445a900bf900b314d381ec0a10f71..80dc9fa3163f1046825aedff134177fb19ac78bb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -29,8 +29,8 @@ import org.openapitools.client.model.Category;
 import org.openapitools.client.model.Tag;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -334,7 +334,12 @@ public class Pet {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `category` to the URL query string
     if (getCategory() != null) {
@@ -342,13 +347,23 @@ public class Pet {
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `photoUrls` to the URL query string
     if (getPhotoUrls() != null) {
       int i = 0;
       for (String _item : getPhotoUrls()) {
-        joiner.add(String.format("%s[photoUrls][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        try {
+          joiner.add(String.format("%s[photoUrls][%d]=%s", prefix, i, URLEncoder.encode(String.valueOf(_item), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
       }
       i++;
     }
@@ -362,7 +377,12 @@ public class Pet {
     }
     // add `status` to the URL query string
     if (getStatus() != null) {
-      joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[status]=%s", prefix, URLEncoder.encode(String.valueOf(getStatus()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 2c90dfdfe4711c237e17138012f6f4abc699b7bc..10cab3b31a6525ba9cc3269d25b5a54ccf20e729 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -145,11 +145,21 @@ public class ReadOnlyFirst {
     StringJoiner joiner = new StringJoiner("&");
     // add `bar` to the URL query string
     if (getBar() != null) {
-      joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[bar]=%s", prefix, URLEncoder.encode(String.valueOf(getBar()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `baz` to the URL query string
     if (getBaz() != null) {
-      joiner.add(String.format("%s[baz]=%s", prefix, URLEncoder.encode(String.valueOf(getBaz()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[baz]=%s", prefix, URLEncoder.encode(String.valueOf(getBaz()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SingleRefType.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SingleRefType.java
index b78ca3721e03572a2cff18e396091e83d0f19a22..7ba697527b72f0d2301970c532e0f12d81b9fee0 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SingleRefType.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SingleRefType.java
@@ -17,8 +17,8 @@ import java.util.Objects;
 import java.util.Arrays;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
index be784d338e3b4a459a819b040531711b9557901d..044f339c5b7d6d5c938794fdc14a512c07ecdabf 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -117,7 +117,12 @@ public class SpecialModelName {
     StringJoiner joiner = new StringJoiner("&");
     // add `$special[property.name]` to the URL query string
     if (get$SpecialPropertyName() != null) {
-      joiner.add(String.format("%s[$special[property.name]]=%s", prefix, URLEncoder.encode(String.valueOf(get$SpecialPropertyName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[$special[property.name]]=%s", prefix, URLEncoder.encode(String.valueOf(get$SpecialPropertyName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
index d6aebac4bb74a8ba0ed404eca8bdc26010a098ce..42ac6b285fb823f21bc2b598c9f552fef4ac0a00 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -148,11 +148,21 @@ public class Tag {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `name` to the URL query string
     if (getName() != null) {
-      joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[name]=%s", prefix, URLEncoder.encode(String.valueOf(getName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
index 52bd08f88931da6ab7977ddc4121a49cb46a2f68..719ceb671abaf023432e254f2393063674a9a94d 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
@@ -22,8 +22,8 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.StringJoiner;
 
 /**
@@ -340,35 +340,75 @@ public class User {
     StringJoiner joiner = new StringJoiner("&");
     // add `id` to the URL query string
     if (getId() != null) {
-      joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[id]=%s", prefix, URLEncoder.encode(String.valueOf(getId()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `username` to the URL query string
     if (getUsername() != null) {
-      joiner.add(String.format("%s[username]=%s", prefix, URLEncoder.encode(String.valueOf(getUsername()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[username]=%s", prefix, URLEncoder.encode(String.valueOf(getUsername()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `firstName` to the URL query string
     if (getFirstName() != null) {
-      joiner.add(String.format("%s[firstName]=%s", prefix, URLEncoder.encode(String.valueOf(getFirstName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[firstName]=%s", prefix, URLEncoder.encode(String.valueOf(getFirstName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `lastName` to the URL query string
     if (getLastName() != null) {
-      joiner.add(String.format("%s[lastName]=%s", prefix, URLEncoder.encode(String.valueOf(getLastName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[lastName]=%s", prefix, URLEncoder.encode(String.valueOf(getLastName()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `email` to the URL query string
     if (getEmail() != null) {
-      joiner.add(String.format("%s[email]=%s", prefix, URLEncoder.encode(String.valueOf(getEmail()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[email]=%s", prefix, URLEncoder.encode(String.valueOf(getEmail()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `password` to the URL query string
     if (getPassword() != null) {
-      joiner.add(String.format("%s[password]=%s", prefix, URLEncoder.encode(String.valueOf(getPassword()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[password]=%s", prefix, URLEncoder.encode(String.valueOf(getPassword()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `phone` to the URL query string
     if (getPhone() != null) {
-      joiner.add(String.format("%s[phone]=%s", prefix, URLEncoder.encode(String.valueOf(getPhone()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[phone]=%s", prefix, URLEncoder.encode(String.valueOf(getPhone()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     // add `userStatus` to the URL query string
     if (getUserStatus() != null) {
-      joiner.add(String.format("%s[userStatus]=%s", prefix, URLEncoder.encode(String.valueOf(getUserStatus()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      try {
+        joiner.add(String.format("%s[userStatus]=%s", prefix, URLEncoder.encode(String.valueOf(getUserStatus()), "UTF-8").replaceAll("\\+", "%20")));
+      } catch (UnsupportedEncodingException e) {
+        // Should never happen, UTF-8 is always supported
+        throw new RuntimeException(e);
+      }
     }
     return joiner.toString();
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 7006df183cfbe770b42d6061cd7e4d67e5733504..d2cedf566a10152c86fc11519af4f79f32759d20 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -156,7 +156,6 @@ public class AdditionalPropertiesClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index b71cb02f4887d99af7a7cf9508cafdef52952c11..d6327307bc84c8f2390cacd40a47237d3b33f024 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -139,7 +139,6 @@ public class AllOfWithSingleRef {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
index 3aa750fa35e2c67c569422da30465aa305cb055c..41f93d333f31354968e55dfa1d7ce6052831aa47 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -154,7 +154,6 @@ public class Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 970b580668435807dcc912cab8ff4d4453600ff2..25e3a70ae89c3b7c6ebd6006f90f1a58a5578813 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -118,7 +118,6 @@ public class ArrayOfArrayOfNumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 62b7b79a6f3065df10dcaf0678e93c9ea6396212..f21d71947b4f8bb37e9d53cf18d40dca77afb6d6 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -118,7 +118,6 @@ public class ArrayOfNumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
index dcb8a63918f1d98b01d35cd7146fb4e17200e79d..ef82d407e11df908aef3b5225b831a70c4265140 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -196,7 +196,6 @@ public class ArrayTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
index 2574cdce1669cb5e4a249b0bec2d77d8579c771f..86d5b3ac1c59f1b1296a048fe7fee52be8f32025 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -262,7 +262,6 @@ public class Capitalization {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
index 860702eac84b6aad378c12b87ff4cfb894428b96..9b38295c8892647cee997203fe21a3aa840e3886 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -120,7 +120,6 @@ public class Cat extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/CatAllOf.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/CatAllOf.java
index 8e1e072f81c0cf1b6c7f7641f38833fa43654a25..d0e938528764efe2d1ce5201d59553a91404c6d5 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/CatAllOf.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/CatAllOf.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class CatAllOf {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
index 1872a29caf86124967590f6e920054e6d8c66727..f1c2fe8cf3c105985ee1221b840f5875af70c896 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Category {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
index d25f2c5ca5d31ba6f79c41259a5e9daf57d3817e..fa22b8dbd505550fbdd8af2b2347f3da403a625a 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ClassModel {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
index c585f53bdc7994fe8ad11303f90dd2f41ce2268a..2845ad7612b6cb7eb4f18f33741ce4eaf1fd2e5c 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class Client {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 88f1caf2f2e883d84dcb401249d8115da856e771..938c3ad013f0dae891d300e1151c9ee6c447c230 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -109,7 +109,6 @@ public class DeprecatedObject {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
index 63da5a9f1886f4353c4200dd6bdfdd79c18a0af4..67fe2c689ab332760b7e64f6e63b004059229f2f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -120,7 +120,6 @@ public class Dog extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DogAllOf.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DogAllOf.java
index f9176aebadeca10967db2dd2f06aa9768761816e..51a30fdb2a16de14d76781a879117d164d16e4a4 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DogAllOf.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DogAllOf.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class DogAllOf {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
index 66a53989334b78e9b5aa0970bd3fd8743dfbf69c..6f79cb8ffb42da3ad91cd1019a66e5ed63a88209 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -218,7 +218,6 @@ public class EnumArrays {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumClass.java
index c74eb42a06b08b0d06e1011f687e6a1714ad6bed..b897738ccfb0dd2c9b6deae942133997eaaf228a 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
index 67714bf97651b7b144365b72ee50ae520e24e4ea..c364f9ec024e8aef4aaaa5751fca51bc0b67a584 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -495,7 +495,6 @@ public class EnumTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 9605e93a69bdf0768a85b9c1d65339d503f68975..80cf3a96d69bb30165d3963e6ca0f4f8ae3fbf8f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -149,7 +149,6 @@ public class FileSchemaTestClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
index 35c06af25b09a8e9947c5b5febeaa4952cc3e841..ba27aba573894cccdd819adc950dabe71741efc0 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class Foo {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c5cdb8d3fdea120b6d21ca8e5ca01e925a0c646f..d9926e3ad376d0425a543b9ae7964ceed93a30f9 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class FooGetDefaultResponse {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
index 57e9fc32be41d353487e727b0480c30ed85096ff..e65ec569af31edf3baf6b9218bea3701388cc68a 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -587,7 +587,6 @@ public class FormatTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 016d5a84dfeb52969961fca99a3f9aadf7f555eb..9081d5e803156be4a1c6bedbbc10f8e3d89fe181 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -128,7 +128,6 @@ public class HasOnlyReadOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index ddc8e843926bec411e208e7d433a282bb9fd5f08..4b8c287d70b415d9f7e297f81415e303e9a45423 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -130,7 +130,6 @@ public class HealthCheckResult {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
index 5edaec5cd7d4868c607955518ff46b40d0f5af68..c04f87b0aefec7bfcfa7ed821f0d2c962131e8f1 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -269,7 +269,6 @@ public class MapTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index d6c0fbba9d712262db205d59b846f9cfd4c8fde2..c5b248d25cdec0627f87c4aaaff9c549532befa3 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -182,7 +182,6 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
index 3bd5189ebf9ba2557f517092cf531efc8227d774..5fe66d610346c2fd43727f79b97e1ca5fac494cc 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Model200Response {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 2ee58c4ff82e859d1109bc42a53d89dff3a0639a..0fda9e671417936702798645567543278709b9da 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -169,7 +169,6 @@ public class ModelApiResponse {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
index 5b5069b2f9a820bd8181d21dbd65beef456910e2..149d2288e000861f8f804cbd29c9e8d58982e0dd 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelFile {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
index a347065b3767510b3572a6fb7293821ca3d8cfd3..379d7c63c614d35018ef73b16dea390c72516d74 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelList {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
index 7b9127c22094b36fba180705dc16ae585375d1ac..b3ad44926981fb97d2fe509f72658898aeb27b34 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelReturn {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
index 261f3f024f9359ea494d36dd12d6fdc7d981bb20..13e43af8c2e8f758141f49e2765e93d8db52add1 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -190,7 +190,6 @@ public class Name {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
index 96634937a4f01f10bf06d5026c89897a6c1b31da..9877503e43cbae4759a35f364d35f766be9cf4af 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -19,11 +19,11 @@ import com.fasterxml.jackson.annotation.JsonAnyGetter;
 import com.fasterxml.jackson.annotation.JsonAnySetter;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -665,7 +665,6 @@ public class NullableClass extends HashMap<String, Object> {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2414c372836ca89f2012e77f05d44af0f9590ec0..bcde8140bd8f7ef55519aae6979fa47ef99f637f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class NumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 1969ac6d4da07b0a8ae3f8ac0c6f9d4a179c7fdd..1c2be218ce3b5577c5a94f4bc6ec15c202a9c46d 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -218,7 +218,6 @@ public class ObjectWithDeprecatedFields {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
index aa6a6530cc9dd020ba236027cad44e1e88c6e0a9..3f5c901bdbf65771c7da270d875e68fbdf032974 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -300,7 +300,6 @@ public class Order {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
index 9614576d84a5ae1381f4e11efadc263089229c16..13c55053ef64b2bd75bd03ebc2574a3759cb5422 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -170,7 +170,6 @@ public class OuterComposite {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnum.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnum.java
index 953d8fc622f6516febef70655dcc1da288760f22..5fbedb0c365ec2a9e7faf45d79346aede31fecf9 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnum.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnum.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
index 91e90954f7aa2120948fc390845c84378a2313cb..e86f08c1b25d7542f46502d0552e663a507e83ee 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumInteger.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
index 7cc4f5b61113e0147717ad7ad5a33bf603252eb9..6383087cc47ce2198764da9dc867933d27e03e6f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
index c6ca3f9e9c33a59fb09087f8ae61252cda8bd69b..ead9d92d93b647dbe339cceb0922d70b5d148c7f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 27f8c25c607b38c5b103e59d0fcdfba247a0bd15..1f5e24849c40aca1b7b492038bda1ac01f874c23 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class OuterObjectWithEnumProperty {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
index f86c763e71da896b58450f4135f02d3034962018..a022ceb32387b2aeb96da6c501789ef94b76617d 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -320,7 +320,6 @@ public class Pet {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index a72dde92663ca96996747d6ebce43f37b909fd96..26c283c8db3316a6c4924756ea7c084b42052613 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -136,7 +136,6 @@ public class ReadOnlyFirst {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SingleRefType.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SingleRefType.java
index f5a6f7af3448b3fa76dab135c8b4e2818021298c..ecb7c27044338f3018f09f9815412f33179faa75 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SingleRefType.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SingleRefType.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 22fe4bfdf6158f03bffd9ace3c5484e1cff8a41b..b4fb3d3e65fc148d89046684449d846db41c89d2 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class SpecialModelName {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
index abb07246b92f24f8ade19cdb6e0bf02dfc1082e2..b37809ad1842b77f39dd37889784f2885d83dd6a 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Tag {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
index 3c51a0bc9e2122d4ea8f95a8d42f6b664586743d..6094289963303b0078f790fbce10576d841524cb 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -324,7 +324,6 @@ public class User {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
index 35b039460b54977bc8c3edd13b5954ca54150f54..6175f25d974cdce8e40582ac032d227d15e8cac7 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Category {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index f2371cbfa20d1853789fde71492f1de6ac1a082f..d73aea6ec3414fd4afa1a19480751bcd167ba280 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -169,7 +169,6 @@ public class ModelApiResponse {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
index 5e7005c889da929f5b2b51b2e5a2872d13af8247..ccae85f71c21b8d3844a7d39c9022ddc46df3f6c 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -300,7 +300,6 @@ public class Order {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index 44df5060dab62d4f3345fc31d83140cdfe8d4559..60fdec3bab0721f2b71a05e7a8fd67ba87f54025 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -318,7 +318,6 @@ public class Pet {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
index b4bec650cff164aee57e5bdad790782a7e2645e1..f0417750de66a4f181b1589ff8e17f3e5329cb04 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Tag {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
index fc0228b7dca2cc11f3866c4d626420d71931ad01..a5f43504f82426aef53ccdece5f03026c1f155f0 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -324,7 +324,6 @@ public class User {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 7006df183cfbe770b42d6061cd7e4d67e5733504..d2cedf566a10152c86fc11519af4f79f32759d20 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -156,7 +156,6 @@ public class AdditionalPropertiesClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index b71cb02f4887d99af7a7cf9508cafdef52952c11..d6327307bc84c8f2390cacd40a47237d3b33f024 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -139,7 +139,6 @@ public class AllOfWithSingleRef {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
index 3aa750fa35e2c67c569422da30465aa305cb055c..41f93d333f31354968e55dfa1d7ce6052831aa47 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -154,7 +154,6 @@ public class Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 970b580668435807dcc912cab8ff4d4453600ff2..25e3a70ae89c3b7c6ebd6006f90f1a58a5578813 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -118,7 +118,6 @@ public class ArrayOfArrayOfNumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 62b7b79a6f3065df10dcaf0678e93c9ea6396212..f21d71947b4f8bb37e9d53cf18d40dca77afb6d6 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -118,7 +118,6 @@ public class ArrayOfNumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
index dcb8a63918f1d98b01d35cd7146fb4e17200e79d..ef82d407e11df908aef3b5225b831a70c4265140 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -196,7 +196,6 @@ public class ArrayTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
index 2574cdce1669cb5e4a249b0bec2d77d8579c771f..86d5b3ac1c59f1b1296a048fe7fee52be8f32025 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -262,7 +262,6 @@ public class Capitalization {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
index 860702eac84b6aad378c12b87ff4cfb894428b96..9b38295c8892647cee997203fe21a3aa840e3886 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -120,7 +120,6 @@ public class Cat extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/CatAllOf.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/CatAllOf.java
index 8e1e072f81c0cf1b6c7f7641f38833fa43654a25..d0e938528764efe2d1ce5201d59553a91404c6d5 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/CatAllOf.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/CatAllOf.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class CatAllOf {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
index 1872a29caf86124967590f6e920054e6d8c66727..f1c2fe8cf3c105985ee1221b840f5875af70c896 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Category {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
index d25f2c5ca5d31ba6f79c41259a5e9daf57d3817e..fa22b8dbd505550fbdd8af2b2347f3da403a625a 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ClassModel {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
index c585f53bdc7994fe8ad11303f90dd2f41ce2268a..2845ad7612b6cb7eb4f18f33741ce4eaf1fd2e5c 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class Client {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 88f1caf2f2e883d84dcb401249d8115da856e771..938c3ad013f0dae891d300e1151c9ee6c447c230 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -109,7 +109,6 @@ public class DeprecatedObject {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
index 63da5a9f1886f4353c4200dd6bdfdd79c18a0af4..67fe2c689ab332760b7e64f6e63b004059229f2f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -120,7 +120,6 @@ public class Dog extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DogAllOf.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DogAllOf.java
index f9176aebadeca10967db2dd2f06aa9768761816e..51a30fdb2a16de14d76781a879117d164d16e4a4 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DogAllOf.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DogAllOf.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class DogAllOf {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
index 66a53989334b78e9b5aa0970bd3fd8743dfbf69c..6f79cb8ffb42da3ad91cd1019a66e5ed63a88209 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -218,7 +218,6 @@ public class EnumArrays {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumClass.java
index c74eb42a06b08b0d06e1011f687e6a1714ad6bed..b897738ccfb0dd2c9b6deae942133997eaaf228a 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
index 67714bf97651b7b144365b72ee50ae520e24e4ea..c364f9ec024e8aef4aaaa5751fca51bc0b67a584 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -495,7 +495,6 @@ public class EnumTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 9605e93a69bdf0768a85b9c1d65339d503f68975..80cf3a96d69bb30165d3963e6ca0f4f8ae3fbf8f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -149,7 +149,6 @@ public class FileSchemaTestClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
index 35c06af25b09a8e9947c5b5febeaa4952cc3e841..ba27aba573894cccdd819adc950dabe71741efc0 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class Foo {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c5cdb8d3fdea120b6d21ca8e5ca01e925a0c646f..d9926e3ad376d0425a543b9ae7964ceed93a30f9 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class FooGetDefaultResponse {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
index 57e9fc32be41d353487e727b0480c30ed85096ff..e65ec569af31edf3baf6b9218bea3701388cc68a 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -587,7 +587,6 @@ public class FormatTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 016d5a84dfeb52969961fca99a3f9aadf7f555eb..9081d5e803156be4a1c6bedbbc10f8e3d89fe181 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -128,7 +128,6 @@ public class HasOnlyReadOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index ddc8e843926bec411e208e7d433a282bb9fd5f08..4b8c287d70b415d9f7e297f81415e303e9a45423 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -130,7 +130,6 @@ public class HealthCheckResult {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
index 5edaec5cd7d4868c607955518ff46b40d0f5af68..c04f87b0aefec7bfcfa7ed821f0d2c962131e8f1 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -269,7 +269,6 @@ public class MapTest {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index d6c0fbba9d712262db205d59b846f9cfd4c8fde2..c5b248d25cdec0627f87c4aaaff9c549532befa3 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -182,7 +182,6 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
index 3bd5189ebf9ba2557f517092cf531efc8227d774..5fe66d610346c2fd43727f79b97e1ca5fac494cc 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Model200Response {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 2ee58c4ff82e859d1109bc42a53d89dff3a0639a..0fda9e671417936702798645567543278709b9da 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -169,7 +169,6 @@ public class ModelApiResponse {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
index 5b5069b2f9a820bd8181d21dbd65beef456910e2..149d2288e000861f8f804cbd29c9e8d58982e0dd 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelFile {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
index a347065b3767510b3572a6fb7293821ca3d8cfd3..379d7c63c614d35018ef73b16dea390c72516d74 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelList {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
index 7b9127c22094b36fba180705dc16ae585375d1ac..b3ad44926981fb97d2fe509f72658898aeb27b34 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class ModelReturn {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
index 261f3f024f9359ea494d36dd12d6fdc7d981bb20..13e43af8c2e8f758141f49e2765e93d8db52add1 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -190,7 +190,6 @@ public class Name {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
index 96634937a4f01f10bf06d5026c89897a6c1b31da..9877503e43cbae4759a35f364d35f766be9cf4af 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -19,11 +19,11 @@ import com.fasterxml.jackson.annotation.JsonAnyGetter;
 import com.fasterxml.jackson.annotation.JsonAnySetter;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -665,7 +665,6 @@ public class NullableClass extends HashMap<String, Object> {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2414c372836ca89f2012e77f05d44af0f9590ec0..bcde8140bd8f7ef55519aae6979fa47ef99f637f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class NumberOnly {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 1969ac6d4da07b0a8ae3f8ac0c6f9d4a179c7fdd..1c2be218ce3b5577c5a94f4bc6ec15c202a9c46d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -218,7 +218,6 @@ public class ObjectWithDeprecatedFields {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
index aa6a6530cc9dd020ba236027cad44e1e88c6e0a9..3f5c901bdbf65771c7da270d875e68fbdf032974 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -300,7 +300,6 @@ public class Order {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
index 9614576d84a5ae1381f4e11efadc263089229c16..13c55053ef64b2bd75bd03ebc2574a3759cb5422 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -170,7 +170,6 @@ public class OuterComposite {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnum.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnum.java
index 953d8fc622f6516febef70655dcc1da288760f22..5fbedb0c365ec2a9e7faf45d79346aede31fecf9 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnum.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnum.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
index 91e90954f7aa2120948fc390845c84378a2313cb..e86f08c1b25d7542f46502d0552e663a507e83ee 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumInteger.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
index 7cc4f5b61113e0147717ad7ad5a33bf603252eb9..6383087cc47ce2198764da9dc867933d27e03e6f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumInteger.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
index c6ca3f9e9c33a59fb09087f8ae61252cda8bd69b..ead9d92d93b647dbe339cceb0922d70b5d148c7f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 27f8c25c607b38c5b103e59d0fcdfba247a0bd15..1f5e24849c40aca1b7b492038bda1ac01f874c23 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -108,7 +108,6 @@ public class OuterObjectWithEnumProperty {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
index f86c763e71da896b58450f4135f02d3034962018..a022ceb32387b2aeb96da6c501789ef94b76617d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -320,7 +320,6 @@ public class Pet {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index a72dde92663ca96996747d6ebce43f37b909fd96..26c283c8db3316a6c4924756ea7c084b42052613 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -136,7 +136,6 @@ public class ReadOnlyFirst {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SingleRefType.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SingleRefType.java
index f5a6f7af3448b3fa76dab135c8b4e2818021298c..ecb7c27044338f3018f09f9815412f33179faa75 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SingleRefType.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SingleRefType.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 22fe4bfdf6158f03bffd9ace3c5484e1cff8a41b..b4fb3d3e65fc148d89046684449d846db41c89d2 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -107,7 +107,6 @@ public class SpecialModelName {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
index abb07246b92f24f8ade19cdb6e0bf02dfc1082e2..b37809ad1842b77f39dd37889784f2885d83dd6a 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -138,7 +138,6 @@ public class Tag {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
index 3c51a0bc9e2122d4ea8f95a8d42f6b664586743d..6094289963303b0078f790fbce10576d841524cb 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
@@ -15,11 +15,11 @@ package org.openapitools.client.model;
 
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.util.StringJoiner;
 import java.util.Objects;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.HashMap;
-import java.util.StringJoiner;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -324,7 +324,6 @@ public class User {
     return o.toString().replace("\n", "\n    ");
   }
 
-
   /**
    * Convert the instance into URL query string.
    *