[java][native] Fix urlQuery string method in oneOf (#14488)

* better tests, fix oneOf in urlquery string method

* update samples

* update

bin/configs/java-native-async.yaml

@@ -1,7 +1,7 @@
 generatorName: java
 outputDir: samples/client/petstore/java/native-async
 library: native
-inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/java/native/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
 templateDir: modules/openapi-generator/src/main/resources/Java
 additionalProperties:
   artifactId: petstore-native

bin/configs/java-native.yaml

@@ -1,7 +1,7 @@
 generatorName: java
 outputDir: samples/client/petstore/java/native
 library: native
-inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/java/native/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
 templateDir: modules/openapi-generator/src/main/resources/Java
 additionalProperties:
   artifactId: petstore-native

modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache

@@ -372,7 +372,7 @@ public class {{classname}} {
                 {{/hasVars}}
                 {{^hasVars}}
                 {{#isModel}}
-    localVarQueryStringJoiner.add({{paramName}}.toUrlQueryString(null));
+    localVarQueryStringJoiner.add({{paramName}}.toUrlQueryString());
                 {{/isModel}}
                 {{^isModel}}
     localVarQueryParams.addAll(ApiClient.parameterToPairs("{{baseName}}", {{paramName}}));

modules/openapi-generator/src/main/resources/Java/libraries/native/oneof_model.mustache

@@ -228,4 +228,166 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     {{/oneOf}}
+
+{{#supportUrlQuery}}
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    {{#composedSchemas.oneOf}}
+    if (getActualInstance() instanceof {{{dataType}}}) {
+        {{#isArray}}
+        {{#items.isPrimitiveType}}
+        {{#uniqueItems}}
+        if (getActualInstance() != null) {
+          int i = 0;
+          for ({{items.dataType}} _item : ({{{dataType}}})getActualInstance()) {
+            joiner.add(String.format("%s{{baseName}}%s%s=%s", prefix, suffix,
+                "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
+                URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          }
+          i++;
+        }
+        {{/uniqueItems}}
+        {{^uniqueItems}}
+        if (getActualInstance() != null) {
+          for (int i = 0; i < (({{{dataType}}})getActualInstance()).size(); i++) {
+            joiner.add(String.format("%s{{baseName}}%s%s=%s", prefix, suffix,
+                "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
+                URLEncoder.encode(String.valueOf(getActualInstance().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          }
+        }
+        {{/uniqueItems}}
+        {{/items.isPrimitiveType}}
+        {{^items.isPrimitiveType}}
+        {{#items.isModel}}
+        {{#uniqueItems}}
+        if (getActualInstance() != null) {
+          int i = 0;
+          for ({{items.dataType}} _item : ({{{dataType}}})getActualInstance()) {
+            if ((({{{dataType}}})getActualInstance()).get(i) != null) {
+              joiner.add(_item.toUrlQueryString(String.format("%s{{baseName}}%s%s", prefix, suffix,
+                  "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix))));
+            }
+          }
+          i++;
+        }
+        {{/uniqueItems}}
+        {{^uniqueItems}}
+        if (getActualInstance() != null) {
+          for (int i = 0; i < (({{{dataType}}})getActualInstance()).size(); i++) {
+            if ((({{{dataType}}})getActualInstance()).get(i) != null) {
+              joiner.add((({{{items.dataType}}})getActualInstance()).get(i).toUrlQueryString(String.format("%s{{baseName}}%s%s", prefix, suffix,
+              "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix))));
+            }
+          }
+        }
+        {{/uniqueItems}}
+        {{/items.isModel}}
+        {{^items.isModel}}
+        {{#uniqueItems}}
+        if (getActualInstance() != null) {
+          int i = 0;
+          for ({{items.dataType}} _item : ({{{dataType}}})getActualInstance()) {
+            if (_item != null) {
+              joiner.add(String.format("%s{{baseName}}%s%s=%s", prefix, suffix,
+                  "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix)),
+                  URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20"));
+            }
+            i++;
+          }
+        }
+        {{/uniqueItems}}
+        {{^uniqueItems}}
+        if (getActualInstance() != null) {
+          for (int i = 0; i < (({{{dataType}}})getActualInstance()).size(); i++) {
+            if (getActualInstance().get(i) != null) {
+              joiner.add(String.format("%s{{baseName}}%s%s=%s", prefix, suffix,
+                  "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
+                  URLEncoder.encode(String.valueOf((({{{dataType}}})getActualInstance()).get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+            }
+          }
+        }
+        {{/uniqueItems}}
+        {{/items.isModel}}
+        {{/items.isPrimitiveType}}
+        {{/isArray}}
+        {{^isArray}}
+        {{#isMap}}
+        {{#items.isPrimitiveType}}
+        if (getActualInstance() != null) {
+          for (String _key : (({{{dataType}}})getActualInstance()).keySet()) {
+            joiner.add(String.format("%s{{baseName}}%s%s=%s", prefix, suffix,
+                "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, _key, containerSuffix),
+                getActualInstance().get(_key), URLEncoder.encode(String.valueOf((({{{dataType}}})getActualInstance()).get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+          }
+        }
+        {{/items.isPrimitiveType}}
+        {{^items.isPrimitiveType}}
+        if (getActualInstance() != null) {
+          for (String _key : (({{{dataType}}})getActualInstance()).keySet()) {
+            if ((({{{dataType}}})getActualInstance()).get(_key) != null) {
+              joiner.add((({{{items.dataType}}})getActualInstance()).get(_key).toUrlQueryString(String.format("%s{{baseName}}%s%s", prefix, suffix,
+                  "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, _key, containerSuffix))));
+            }
+          }
+        }
+        {{/items.isPrimitiveType}}
+        {{/isMap}}
+        {{^isMap}}
+        {{#isPrimitiveType}}
+        if (getActualInstance() != null) {
+          joiner.add(String.format("%s{{{baseName}}}%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getActualInstance()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        }
+        {{/isPrimitiveType}}
+        {{^isPrimitiveType}}
+        {{#isModel}}
+        if (getActualInstance() != null) {
+          joiner.add((({{{dataType}}})getActualInstance()).toUrlQueryString(prefix + "{{{baseName}}}" + suffix));
+        }
+        {{/isModel}}
+        {{^isModel}}
+        if (getActualInstance() != null) {
+          joiner.add(String.format("%s{{{baseName}}}%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getActualInstance()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        }
+        {{/isModel}}
+        {{/isPrimitiveType}}
+        {{/isMap}}
+        {{/isArray}}
+        return joiner.toString();
+    }
+    {{/composedSchemas.oneOf}}
+    return null;
+  }
+{{/supportUrlQuery}}
+
 }

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/QueryApi.java

@@ -610,7 +610,7 @@ public class QueryApi {
     StringJoiner localVarQueryStringJoiner = new StringJoiner("&");
     String localVarQueryParameterBaseName;
     localVarQueryParameterBaseName = "query_object";
-    localVarQueryStringJoiner.add(queryObject.toUrlQueryString(null));
+    localVarQueryStringJoiner.add(queryObject.toUrlQueryString());
 
     if (!localVarQueryParams.isEmpty() || localVarQueryStringJoiner.length() != 0) {
       StringJoiner queryJoiner = new StringJoiner("&");

samples/client/petstore/java/native-async/.openapi-generator/FILES

@@ -6,33 +6,49 @@ api/openapi.yaml
 build.gradle
 build.sbt
 docs/AdditionalPropertiesClass.md
-docs/AllOfWithSingleRef.md
 docs/Animal.md
 docs/AnotherFakeApi.md
+docs/Apple.md
+docs/AppleReq.md
 docs/ArrayOfArrayOfNumberOnly.md
 docs/ArrayOfNumberOnly.md
 docs/ArrayTest.md
+docs/Banana.md
+docs/BananaReq.md
+docs/BasquePig.md
 docs/Capitalization.md
 docs/Cat.md
 docs/CatAllOf.md
 docs/Category.md
+docs/ChildCat.md
+docs/ChildCatAllOf.md
 docs/ClassModel.md
 docs/Client.md
+docs/ComplexQuadrilateral.md
+docs/DanishPig.md
 docs/DefaultApi.md
 docs/DeprecatedObject.md
 docs/Dog.md
 docs/DogAllOf.md
+docs/Drawing.md
 docs/EnumArrays.md
 docs/EnumClass.md
 docs/EnumTest.md
+docs/EquilateralTriangle.md
 docs/FakeApi.md
 docs/FakeClassnameTags123Api.md
 docs/FileSchemaTestClass.md
 docs/Foo.md
 docs/FooGetDefaultResponse.md
 docs/FormatTest.md
+docs/Fruit.md
+docs/FruitReq.md
+docs/GmFruit.md
+docs/GrandparentAnimal.md
 docs/HasOnlyReadOnly.md
 docs/HealthCheckResult.md
+docs/IsoscelesTriangle.md
+docs/Mammal.md
 docs/MapTest.md
 docs/MixedPropertiesAndAdditionalPropertiesClass.md
 docs/Model200Response.md
@@ -42,6 +58,7 @@ docs/ModelList.md
 docs/ModelReturn.md
 docs/Name.md
 docs/NullableClass.md
+docs/NullableShape.md
 docs/NumberOnly.md
 docs/ObjectWithDeprecatedFields.md
 docs/Order.md
@@ -50,16 +67,27 @@ docs/OuterEnum.md
 docs/OuterEnumDefaultValue.md
 docs/OuterEnumInteger.md
 docs/OuterEnumIntegerDefaultValue.md
-docs/OuterObjectWithEnumProperty.md
+docs/ParentPet.md
 docs/Pet.md
 docs/PetApi.md
+docs/Pig.md
+docs/Quadrilateral.md
+docs/QuadrilateralInterface.md
 docs/ReadOnlyFirst.md
-docs/SingleRefType.md
+docs/ScaleneTriangle.md
+docs/Shape.md
+docs/ShapeInterface.md
+docs/ShapeOrNull.md
+docs/SimpleQuadrilateral.md
 docs/SpecialModelName.md
 docs/StoreApi.md
 docs/Tag.md
+docs/Triangle.md
+docs/TriangleInterface.md
 docs/User.md
 docs/UserApi.md
+docs/Whale.md
+docs/Zebra.md
 git_push.sh
 gradle.properties
 gradle/wrapper/gradle-wrapper.jar
@@ -87,29 +115,45 @@ src/main/java/org/openapitools/client/api/StoreApi.java
 src/main/java/org/openapitools/client/api/UserApi.java
 src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
 src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
-src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
 src/main/java/org/openapitools/client/model/Animal.java
+src/main/java/org/openapitools/client/model/Apple.java
+src/main/java/org/openapitools/client/model/AppleReq.java
 src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
 src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
 src/main/java/org/openapitools/client/model/ArrayTest.java
+src/main/java/org/openapitools/client/model/Banana.java
+src/main/java/org/openapitools/client/model/BananaReq.java
+src/main/java/org/openapitools/client/model/BasquePig.java
 src/main/java/org/openapitools/client/model/Capitalization.java
 src/main/java/org/openapitools/client/model/Cat.java
 src/main/java/org/openapitools/client/model/CatAllOf.java
 src/main/java/org/openapitools/client/model/Category.java
+src/main/java/org/openapitools/client/model/ChildCat.java
+src/main/java/org/openapitools/client/model/ChildCatAllOf.java
 src/main/java/org/openapitools/client/model/ClassModel.java
 src/main/java/org/openapitools/client/model/Client.java
+src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+src/main/java/org/openapitools/client/model/DanishPig.java
 src/main/java/org/openapitools/client/model/DeprecatedObject.java
 src/main/java/org/openapitools/client/model/Dog.java
 src/main/java/org/openapitools/client/model/DogAllOf.java
+src/main/java/org/openapitools/client/model/Drawing.java
 src/main/java/org/openapitools/client/model/EnumArrays.java
 src/main/java/org/openapitools/client/model/EnumClass.java
 src/main/java/org/openapitools/client/model/EnumTest.java
+src/main/java/org/openapitools/client/model/EquilateralTriangle.java
 src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
 src/main/java/org/openapitools/client/model/Foo.java
 src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
 src/main/java/org/openapitools/client/model/FormatTest.java
+src/main/java/org/openapitools/client/model/Fruit.java
+src/main/java/org/openapitools/client/model/FruitReq.java
+src/main/java/org/openapitools/client/model/GmFruit.java
+src/main/java/org/openapitools/client/model/GrandparentAnimal.java
 src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
 src/main/java/org/openapitools/client/model/HealthCheckResult.java
+src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+src/main/java/org/openapitools/client/model/Mammal.java
 src/main/java/org/openapitools/client/model/MapTest.java
 src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
 src/main/java/org/openapitools/client/model/Model200Response.java
@@ -119,6 +163,7 @@ src/main/java/org/openapitools/client/model/ModelList.java
 src/main/java/org/openapitools/client/model/ModelReturn.java
 src/main/java/org/openapitools/client/model/Name.java
 src/main/java/org/openapitools/client/model/NullableClass.java
+src/main/java/org/openapitools/client/model/NullableShape.java
 src/main/java/org/openapitools/client/model/NumberOnly.java
 src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
 src/main/java/org/openapitools/client/model/Order.java
@@ -127,10 +172,21 @@ src/main/java/org/openapitools/client/model/OuterEnum.java
 src/main/java/org/openapitools/client/model/OuterEnumDefaultValue.java
 src/main/java/org/openapitools/client/model/OuterEnumInteger.java
 src/main/java/org/openapitools/client/model/OuterEnumIntegerDefaultValue.java
-src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+src/main/java/org/openapitools/client/model/ParentPet.java
 src/main/java/org/openapitools/client/model/Pet.java
+src/main/java/org/openapitools/client/model/Pig.java
+src/main/java/org/openapitools/client/model/Quadrilateral.java
+src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
 src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
-src/main/java/org/openapitools/client/model/SingleRefType.java
+src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+src/main/java/org/openapitools/client/model/Shape.java
+src/main/java/org/openapitools/client/model/ShapeInterface.java
+src/main/java/org/openapitools/client/model/ShapeOrNull.java
+src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
 src/main/java/org/openapitools/client/model/SpecialModelName.java
 src/main/java/org/openapitools/client/model/Tag.java
+src/main/java/org/openapitools/client/model/Triangle.java
+src/main/java/org/openapitools/client/model/TriangleInterface.java
 src/main/java/org/openapitools/client/model/User.java
+src/main/java/org/openapitools/client/model/Whale.java
+src/main/java/org/openapitools/client/model/Zebra.java

samples/client/petstore/java/native-async/README.md

@@ -112,8 +112,6 @@ Class | Method | HTTP request | Description
 *DefaultApi* | [**fooGetWithHttpInfo**](docs/DefaultApi.md#fooGetWithHttpInfo) | **GET** /foo | 
 *FakeApi* | [**fakeHealthGet**](docs/FakeApi.md#fakeHealthGet) | **GET** /fake/health | Health check endpoint
 *FakeApi* | [**fakeHealthGetWithHttpInfo**](docs/FakeApi.md#fakeHealthGetWithHttpInfo) | **GET** /fake/health | Health check endpoint
-*FakeApi* | [**fakeHttpSignatureTest**](docs/FakeApi.md#fakeHttpSignatureTest) | **GET** /fake/http-signature-test | test http signature authentication
-*FakeApi* | [**fakeHttpSignatureTestWithHttpInfo**](docs/FakeApi.md#fakeHttpSignatureTestWithHttpInfo) | **GET** /fake/http-signature-test | test http signature authentication
 *FakeApi* | [**fakeOuterBooleanSerialize**](docs/FakeApi.md#fakeOuterBooleanSerialize) | **POST** /fake/outer/boolean | 
 *FakeApi* | [**fakeOuterBooleanSerializeWithHttpInfo**](docs/FakeApi.md#fakeOuterBooleanSerializeWithHttpInfo) | **POST** /fake/outer/boolean | 
 *FakeApi* | [**fakeOuterCompositeSerialize**](docs/FakeApi.md#fakeOuterCompositeSerialize) | **POST** /fake/outer/composite | 
@@ -122,10 +120,8 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**fakeOuterNumberSerializeWithHttpInfo**](docs/FakeApi.md#fakeOuterNumberSerializeWithHttpInfo) | **POST** /fake/outer/number | 
 *FakeApi* | [**fakeOuterStringSerialize**](docs/FakeApi.md#fakeOuterStringSerialize) | **POST** /fake/outer/string | 
 *FakeApi* | [**fakeOuterStringSerializeWithHttpInfo**](docs/FakeApi.md#fakeOuterStringSerializeWithHttpInfo) | **POST** /fake/outer/string | 
-*FakeApi* | [**fakePropertyEnumIntegerSerialize**](docs/FakeApi.md#fakePropertyEnumIntegerSerialize) | **POST** /fake/property/enum-int | 
+*FakeApi* | [**getArrayOfEnums**](docs/FakeApi.md#getArrayOfEnums) | **GET** /fake/array-of-enums | Array of Enums
-*FakeApi* | [**fakePropertyEnumIntegerSerializeWithHttpInfo**](docs/FakeApi.md#fakePropertyEnumIntegerSerializeWithHttpInfo) | **POST** /fake/property/enum-int | 
+*FakeApi* | [**getArrayOfEnumsWithHttpInfo**](docs/FakeApi.md#getArrayOfEnumsWithHttpInfo) | **GET** /fake/array-of-enums | Array of Enums
-*FakeApi* | [**testBodyWithBinary**](docs/FakeApi.md#testBodyWithBinary) | **PUT** /fake/body-with-binary | 
-*FakeApi* | [**testBodyWithBinaryWithHttpInfo**](docs/FakeApi.md#testBodyWithBinaryWithHttpInfo) | **PUT** /fake/body-with-binary | 
 *FakeApi* | [**testBodyWithFileSchema**](docs/FakeApi.md#testBodyWithFileSchema) | **PUT** /fake/body-with-file-schema | 
 *FakeApi* | [**testBodyWithFileSchemaWithHttpInfo**](docs/FakeApi.md#testBodyWithFileSchemaWithHttpInfo) | **PUT** /fake/body-with-file-schema | 
 *FakeApi* | [**testBodyWithQueryParams**](docs/FakeApi.md#testBodyWithQueryParams) | **PUT** /fake/body-with-query-params | 
@@ -193,29 +189,45 @@ Class | Method | HTTP request | Description
 ## Documentation for Models
 
  - [AdditionalPropertiesClass](docs/AdditionalPropertiesClass.md)
- - [AllOfWithSingleRef](docs/AllOfWithSingleRef.md)
  - [Animal](docs/Animal.md)
+ - [Apple](docs/Apple.md)
+ - [AppleReq](docs/AppleReq.md)
  - [ArrayOfArrayOfNumberOnly](docs/ArrayOfArrayOfNumberOnly.md)
  - [ArrayOfNumberOnly](docs/ArrayOfNumberOnly.md)
  - [ArrayTest](docs/ArrayTest.md)
+ - [Banana](docs/Banana.md)
+ - [BananaReq](docs/BananaReq.md)
+ - [BasquePig](docs/BasquePig.md)
  - [Capitalization](docs/Capitalization.md)
  - [Cat](docs/Cat.md)
  - [CatAllOf](docs/CatAllOf.md)
  - [Category](docs/Category.md)
+ - [ChildCat](docs/ChildCat.md)
+ - [ChildCatAllOf](docs/ChildCatAllOf.md)
  - [ClassModel](docs/ClassModel.md)
  - [Client](docs/Client.md)
+ - [ComplexQuadrilateral](docs/ComplexQuadrilateral.md)
+ - [DanishPig](docs/DanishPig.md)
  - [DeprecatedObject](docs/DeprecatedObject.md)
  - [Dog](docs/Dog.md)
  - [DogAllOf](docs/DogAllOf.md)
+ - [Drawing](docs/Drawing.md)
  - [EnumArrays](docs/EnumArrays.md)
  - [EnumClass](docs/EnumClass.md)
  - [EnumTest](docs/EnumTest.md)
+ - [EquilateralTriangle](docs/EquilateralTriangle.md)
  - [FileSchemaTestClass](docs/FileSchemaTestClass.md)
  - [Foo](docs/Foo.md)
  - [FooGetDefaultResponse](docs/FooGetDefaultResponse.md)
  - [FormatTest](docs/FormatTest.md)
+ - [Fruit](docs/Fruit.md)
+ - [FruitReq](docs/FruitReq.md)
+ - [GmFruit](docs/GmFruit.md)
+ - [GrandparentAnimal](docs/GrandparentAnimal.md)
  - [HasOnlyReadOnly](docs/HasOnlyReadOnly.md)
  - [HealthCheckResult](docs/HealthCheckResult.md)
+ - [IsoscelesTriangle](docs/IsoscelesTriangle.md)
+ - [Mammal](docs/Mammal.md)
  - [MapTest](docs/MapTest.md)
  - [MixedPropertiesAndAdditionalPropertiesClass](docs/MixedPropertiesAndAdditionalPropertiesClass.md)
  - [Model200Response](docs/Model200Response.md)
@@ -225,6 +237,7 @@ Class | Method | HTTP request | Description
  - [ModelReturn](docs/ModelReturn.md)
  - [Name](docs/Name.md)
  - [NullableClass](docs/NullableClass.md)
+ - [NullableShape](docs/NullableShape.md)
  - [NumberOnly](docs/NumberOnly.md)
  - [ObjectWithDeprecatedFields](docs/ObjectWithDeprecatedFields.md)
  - [Order](docs/Order.md)
@@ -233,13 +246,24 @@ Class | Method | HTTP request | Description
  - [OuterEnumDefaultValue](docs/OuterEnumDefaultValue.md)
  - [OuterEnumInteger](docs/OuterEnumInteger.md)
  - [OuterEnumIntegerDefaultValue](docs/OuterEnumIntegerDefaultValue.md)
- - [OuterObjectWithEnumProperty](docs/OuterObjectWithEnumProperty.md)
+ - [ParentPet](docs/ParentPet.md)
  - [Pet](docs/Pet.md)
+ - [Pig](docs/Pig.md)
+ - [Quadrilateral](docs/Quadrilateral.md)
+ - [QuadrilateralInterface](docs/QuadrilateralInterface.md)
  - [ReadOnlyFirst](docs/ReadOnlyFirst.md)
- - [SingleRefType](docs/SingleRefType.md)
+ - [ScaleneTriangle](docs/ScaleneTriangle.md)
+ - [Shape](docs/Shape.md)
+ - [ShapeInterface](docs/ShapeInterface.md)
+ - [ShapeOrNull](docs/ShapeOrNull.md)
+ - [SimpleQuadrilateral](docs/SimpleQuadrilateral.md)
  - [SpecialModelName](docs/SpecialModelName.md)
  - [Tag](docs/Tag.md)
+ - [Triangle](docs/Triangle.md)
+ - [TriangleInterface](docs/TriangleInterface.md)
  - [User](docs/User.md)
+ - [Whale](docs/Whale.md)
+ - [Zebra](docs/Zebra.md)
 
 
 ## Documentation for Authorization

samples/client/petstore/java/native-async/api/openapi.yaml

@@ -32,7 +32,7 @@ servers:
       - v1
       - v2
 - description: The local server without variables
-  url: https://127.0.0.1/no_varaible
+  url: https://127.0.0.1/no_variable
 tags:
 - description: Everything about your Pets
   name: pet
@@ -58,11 +58,10 @@ paths:
       requestBody:
         $ref: '#/components/requestBodies/Pet'
       responses:
-        "200":
-          description: Successful operation
         "405":
           description: Invalid input
       security:
+      - http_signature_test: []
       - petstore_auth:
         - write:pets
         - read:pets
@@ -77,8 +76,6 @@ paths:
       requestBody:
         $ref: '#/components/requestBodies/Pet'
       responses:
-        "200":
-          description: Successful operation
         "400":
           description: Invalid ID supplied
         "404":
@@ -86,33 +83,18 @@ paths:
         "405":
           description: Validation exception
       security:
+      - http_signature_test: []
       - petstore_auth:
         - write:pets
         - read:pets
       summary: Update an existing pet
       tags:
       - pet
-      x-webclient-blocking: true
       x-content-type: application/json
       x-accepts: application/json
     servers:
     - url: http://petstore.swagger.io/v2
     - url: http://path-server-test.petstore.local/v2
-    - description: test server with variables
-      url: "http://{server}.swagger.io:{port}/v2"
-      variables:
-        server:
-          default: petstore
-          description: target server
-          enum:
-          - petstore
-          - qa-petstore
-          - dev-petstore
-        port:
-          default: "80"
-          enum:
-          - "80"
-          - "8080"
   /pet/findByStatus:
     get:
       description: Multiple status values can be provided with comma separated strings
@@ -151,13 +133,13 @@ paths:
         "400":
           description: Invalid status value
       security:
+      - http_signature_test: []
       - petstore_auth:
         - write:pets
         - read:pets
       summary: Finds Pets by status
       tags:
       - pet
-      x-webclient-blocking: true
       x-accepts: application/json
   /pet/findByTags:
     get:
@@ -175,7 +157,6 @@ paths:
           items:
             type: string
           type: array
-          uniqueItems: true
         style: form
       responses:
         "200":
@@ -185,24 +166,22 @@ paths:
                 items:
                   $ref: '#/components/schemas/Pet'
                 type: array
-                uniqueItems: true
             application/json:
               schema:
                 items:
                   $ref: '#/components/schemas/Pet'
                 type: array
-                uniqueItems: true
           description: successful operation
         "400":
           description: Invalid tag value
       security:
+      - http_signature_test: []
       - petstore_auth:
         - write:pets
         - read:pets
       summary: Finds Pets by tags
       tags:
       - pet
-      x-webclient-blocking: true
       x-accepts: application/json
   /pet/{petId}:
     delete:
@@ -226,8 +205,6 @@ paths:
           type: integer
         style: simple
       responses:
-        "200":
-          description: Successful operation
         "400":
           description: Invalid pet value
       security:
@@ -270,7 +247,6 @@ paths:
       summary: Find pet by ID
       tags:
       - pet
-      x-webclient-blocking: true
       x-accepts: application/json
     post:
       description: ""
@@ -291,8 +267,6 @@ paths:
             schema:
               $ref: '#/components/schemas/updatePetWithForm_request'
       responses:
-        "200":
-          description: Successful operation
         "405":
           description: Invalid input
       security:
@@ -358,7 +332,6 @@ paths:
       summary: Returns pet inventories by status
       tags:
       - store
-      x-webclient-blocking: false
       x-accepts: application/json
   /store/order:
     post:
@@ -803,15 +776,6 @@ paths:
           format: double
           type: number
         style: form
-      - explode: true
-        in: query
-        name: enum_query_model_array
-        required: false
-        schema:
-          items:
-            $ref: '#/components/schemas/EnumClass'
-          type: array
-        style: form
       requestBody:
         content:
           application/x-www-form-urlencoded:
@@ -893,28 +857,6 @@ paths:
       - fake
       x-content-type: application/json
       x-accepts: '*/*'
-  /fake/property/enum-int:
-    post:
-      description: Test serialization of enum (int) properties with examples
-      operationId: fakePropertyEnumIntegerSerialize
-      requestBody:
-        content:
-          application/json:
-            schema:
-              $ref: '#/components/schemas/OuterObjectWithEnumProperty'
-        description: Input enum (int) as post body
-        required: true
-      responses:
-        "200":
-          content:
-            '*/*':
-              schema:
-                $ref: '#/components/schemas/OuterObjectWithEnumProperty'
-          description: Output enum (int)
-      tags:
-      - fake
-      x-content-type: application/json
-      x-accepts: '*/*'
   /fake/outer/string:
     post:
       description: Test serialization of outer string types
@@ -1060,7 +1002,7 @@ paths:
       x-accepts: application/json
   /fake/body-with-file-schema:
     put:
-      description: "For this test, the body for this request must reference a schema\
+      description: "For this test, the body for this request much reference a schema\
         \ named `File`."
       operationId: testBodyWithFileSchema
       requestBody:
@@ -1076,32 +1018,12 @@ paths:
       - fake
       x-content-type: application/json
       x-accepts: application/json
-  /fake/body-with-binary:
-    put:
-      description: "For this test, the body has to be a binary file."
-      operationId: testBodyWithBinary
-      requestBody:
-        content:
-          image/png:
-            schema:
-              format: binary
-              nullable: true
-              type: string
-        description: image to upload
-        required: true
-      responses:
-        "200":
-          description: Success
-      tags:
-      - fake
-      x-content-type: image/png
-      x-accepts: application/json
   /fake/test-query-parameters:
     put:
       description: To test the collection format in query parameters
       operationId: testQueryParameterCollectionFormat
       parameters:
-      - explode: false
+      - explode: true
         in: query
         name: pipe
         required: true
@@ -1109,7 +1031,7 @@ paths:
           items:
             type: string
           type: array
-        style: pipeDelimited
+        style: form
       - explode: false
         in: query
         name: ioutil
@@ -1146,24 +1068,6 @@ paths:
             type: string
           type: array
         style: form
-      - explode: true
-        in: query
-        name: language
-        required: false
-        schema:
-          additionalProperties:
-            format: string
-            type: string
-          type: object
-        style: form
-      - allowEmptyValue: true
-        explode: true
-        in: query
-        name: allowEmpty
-        required: true
-        schema:
-          type: string
-        style: form
       responses:
         "200":
           description: Success
@@ -1218,43 +1122,32 @@ paths:
       tags:
       - fake
       x-accepts: application/json
-  /fake/http-signature-test:
+  /fake/array-of-enums:
     get:
-      operationId: fake-http-signature-test
+      operationId: getArrayOfEnums
-      parameters:
-      - description: query parameter
-        explode: true
-        in: query
-        name: query_1
-        required: false
-        schema:
-          type: string
-        style: form
-      - description: header parameter
-        explode: false
-        in: header
-        name: header_1
-        required: false
-        schema:
-          type: string
-        style: simple
-      requestBody:
-        $ref: '#/components/requestBodies/Pet'
       responses:
         "200":
-          description: The instance started successfully
+          content:
-      security:
+            application/json:
-      - http_signature_test: []
+              schema:
-      summary: test http signature authentication
+                $ref: '#/components/schemas/ArrayOfEnums'
+          description: Got named array of enums
+      summary: Array of Enums
       tags:
       - fake
-      x-content-type: application/json
       x-accepts: application/json
 components:
   requestBodies:
     UserArray:
       content:
         application/json:
+          examples:
+            simple-list:
+              description: Should not get into code examples
+              summary: Simple list example
+              value:
+              - username: foo
+              - username: bar
           schema:
             items:
               $ref: '#/components/schemas/User'
@@ -1295,7 +1188,7 @@ components:
         petId: 6
         quantity: 1
         id: 0
-        shipDate: 2000-01-23T04:56:07.000+00:00
+        shipDate: 2020-02-02T20:20:20.000222Z
         complete: false
         status: placed
       properties:
@@ -1309,6 +1202,7 @@ components:
           format: int32
           type: integer
         shipDate:
+          example: 2020-02-02T20:20:20.000222Z
           format: date-time
           type: string
         status:
@@ -1346,9 +1240,13 @@ components:
         lastName: lastName
         password: password
         userStatus: 6
+        objectWithNoDeclaredPropsNullable: "{}"
         phone: phone
+        objectWithNoDeclaredProps: "{}"
         id: 0
+        anyTypePropNullable: ""
         email: email
+        anyTypeProp: ""
         username: username
       properties:
         id:
@@ -1371,6 +1269,25 @@ components:
           description: User Status
           format: int32
           type: integer
+        objectWithNoDeclaredProps:
+          description: test code generation for objects Value must be a map of strings
+            to values. It cannot be the 'null' value.
+          type: object
+        objectWithNoDeclaredPropsNullable:
+          description: test code generation for nullable objects. Value must be a
+            map of strings to values or the 'null' value.
+          nullable: true
+          type: object
+        anyTypeProp:
+          description: "test code generation for any type Here the 'type' attribute\
+            \ is not specified, which means the value can be anything, including the\
+            \ null value, string, number, boolean, array or object. See https://github.com/OAI/OpenAPI-Specification/issues/1389"
+        anyTypePropNullable:
+          description: "test code generation for any type Here the 'type' attribute\
+            \ is not specified, which means the value can be anything, including the\
+            \ null value, string, number, boolean, array or object. The 'nullable'\
+            \ attribute does not change the allowed values."
+          nullable: true
       type: object
       xml:
         name: User
@@ -1417,7 +1334,6 @@ components:
           items:
             type: string
           type: array
-          uniqueItems: true
           xml:
             name: photoUrl
             wrapped: true
@@ -1504,7 +1420,12 @@ components:
     Cat:
       allOf:
       - $ref: '#/components/schemas/Animal'
+      - $ref: '#/components/schemas/Address'
       - $ref: '#/components/schemas/Cat_allOf'
+    Address:
+      additionalProperties:
+        type: integer
+      type: object
     Animal:
       discriminator:
         propertyName: className
@@ -1526,6 +1447,7 @@ components:
         integer:
           maximum: 100
           minimum: 10
+          multipleOf: 2
           type: integer
         int32:
           format: int32
@@ -1538,6 +1460,7 @@ components:
         number:
           maximum: 543.2
           minimum: 32.1
+          multipleOf: 32.5
           type: number
         float:
           format: float
@@ -1562,9 +1485,11 @@ components:
           format: binary
           type: string
         date:
+          example: 2020-02-02
           format: date
           type: string
         dateTime:
+          example: 2007-12-03T10:15:30+01:00
           format: date-time
           type: string
         uuid:
@@ -1618,6 +1543,11 @@ components:
           - -1
           format: int32
           type: integer
+        enum_integer_only:
+          enum:
+          - 2
+          - -2
+          type: integer
         enum_number:
           enum:
           - 1.1
@@ -1647,6 +1577,24 @@ components:
               type: string
             type: object
           type: object
+        anytype_1: {}
+        map_with_undeclared_properties_anytype_1:
+          type: object
+        map_with_undeclared_properties_anytype_2:
+          properties: {}
+          type: object
+        map_with_undeclared_properties_anytype_3:
+          additionalProperties: true
+          type: object
+        empty_map:
+          additionalProperties: false
+          description: "an object with no declared properties and no undeclared properties,\
+            \ hence it's an empty map."
+          type: object
+        map_with_undeclared_properties_string:
+          additionalProperties:
+            type: string
+          type: object
       type: object
     MixedPropertiesAndAdditionalPropertiesClass:
       properties:
@@ -1736,8 +1684,6 @@ components:
         array_of_string:
           items:
             type: string
-          maxItems: 3
-          minItems: 0
           type: array
         array_array_of_integer:
           items:
@@ -1801,7 +1747,6 @@ components:
       - 0
       - 1
       - 2
-      example: 2
       type: integer
     OuterEnumDefaultValue:
       default: placed
@@ -1871,6 +1816,8 @@ components:
         $special[property.name]:
           format: int64
           type: integer
+        _special_model.name_:
+          type: string
       xml:
         name: "$special[model.name]"
     HealthCheckResult:
@@ -1941,15 +1888,231 @@ components:
             type: object
           type: object
       type: object
-    OuterObjectWithEnumProperty:
+    fruit:
-      example:
+      additionalProperties: false
-        value: 2
+      oneOf:
+      - $ref: '#/components/schemas/apple'
+      - $ref: '#/components/schemas/banana'
       properties:
-        value:
+        color:
-          $ref: '#/components/schemas/OuterEnumInteger'
+          type: string
-      required:
+    apple:
-      - value
+      nullable: true
+      properties:
+        cultivar:
+          pattern: "^[a-zA-Z\\s]*$"
+          type: string
+        origin:
+          pattern: "/^[A-Z\\s]*$/i"
+          type: string
       type: object
+    banana:
+      properties:
+        lengthCm:
+          type: number
+      type: object
+    mammal:
+      discriminator:
+        propertyName: className
+      oneOf:
+      - $ref: '#/components/schemas/whale'
+      - $ref: '#/components/schemas/zebra'
+      - $ref: '#/components/schemas/Pig'
+    whale:
+      properties:
+        hasBaleen:
+          type: boolean
+        hasTeeth:
+          type: boolean
+        className:
+          type: string
+      required:
+      - className
+      type: object
+    zebra:
+      additionalProperties: true
+      properties:
+        type:
+          enum:
+          - plains
+          - mountain
+          - grevys
+          type: string
+        className:
+          type: string
+      required:
+      - className
+      type: object
+    Pig:
+      discriminator:
+        propertyName: className
+      oneOf:
+      - $ref: '#/components/schemas/BasquePig'
+      - $ref: '#/components/schemas/DanishPig'
+    BasquePig:
+      properties:
+        className:
+          type: string
+      required:
+      - className
+      type: object
+    DanishPig:
+      properties:
+        className:
+          type: string
+      required:
+      - className
+      type: object
+    gmFruit:
+      additionalProperties: false
+      anyOf:
+      - $ref: '#/components/schemas/apple'
+      - $ref: '#/components/schemas/banana'
+      properties:
+        color:
+          type: string
+    fruitReq:
+      additionalProperties: false
+      oneOf:
+      - $ref: '#/components/schemas/appleReq'
+      - $ref: '#/components/schemas/bananaReq'
+    appleReq:
+      additionalProperties: false
+      properties:
+        cultivar:
+          type: string
+        mealy:
+          type: boolean
+      required:
+      - cultivar
+      type: object
+    bananaReq:
+      additionalProperties: false
+      properties:
+        lengthCm:
+          type: number
+        sweet:
+          type: boolean
+      required:
+      - lengthCm
+      type: object
+    Drawing:
+      additionalProperties:
+        $ref: '#/components/schemas/fruit'
+      properties:
+        mainShape:
+          $ref: '#/components/schemas/Shape'
+        shapeOrNull:
+          $ref: '#/components/schemas/ShapeOrNull'
+        nullableShape:
+          $ref: '#/components/schemas/NullableShape'
+        shapes:
+          items:
+            $ref: '#/components/schemas/Shape'
+          type: array
+      type: object
+    Shape:
+      discriminator:
+        propertyName: shapeType
+      oneOf:
+      - $ref: '#/components/schemas/Triangle'
+      - $ref: '#/components/schemas/Quadrilateral'
+    ShapeOrNull:
+      description: The value may be a shape or the 'null' value. This is introduced
+        in OAS schema >= 3.1.
+      discriminator:
+        propertyName: shapeType
+      oneOf:
+      - $ref: '#/components/schemas/Triangle'
+      - $ref: '#/components/schemas/Quadrilateral'
+    NullableShape:
+      description: The value may be a shape or the 'null' value. The 'nullable' attribute
+        was introduced in OAS schema >= 3.0 and has been deprecated in OAS schema
+        >= 3.1.
+      discriminator:
+        propertyName: shapeType
+      nullable: true
+      oneOf:
+      - $ref: '#/components/schemas/Triangle'
+      - $ref: '#/components/schemas/Quadrilateral'
+    ShapeInterface:
+      properties:
+        shapeType:
+          type: string
+      required:
+      - shapeType
+    TriangleInterface:
+      properties:
+        triangleType:
+          type: string
+      required:
+      - triangleType
+    Triangle:
+      discriminator:
+        propertyName: triangleType
+      oneOf:
+      - $ref: '#/components/schemas/EquilateralTriangle'
+      - $ref: '#/components/schemas/IsoscelesTriangle'
+      - $ref: '#/components/schemas/ScaleneTriangle'
+    EquilateralTriangle:
+      allOf:
+      - $ref: '#/components/schemas/ShapeInterface'
+      - $ref: '#/components/schemas/TriangleInterface'
+    IsoscelesTriangle:
+      additionalProperties: false
+      allOf:
+      - $ref: '#/components/schemas/ShapeInterface'
+      - $ref: '#/components/schemas/TriangleInterface'
+    ScaleneTriangle:
+      allOf:
+      - $ref: '#/components/schemas/ShapeInterface'
+      - $ref: '#/components/schemas/TriangleInterface'
+    QuadrilateralInterface:
+      properties:
+        quadrilateralType:
+          type: string
+      required:
+      - quadrilateralType
+    Quadrilateral:
+      discriminator:
+        propertyName: quadrilateralType
+      oneOf:
+      - $ref: '#/components/schemas/SimpleQuadrilateral'
+      - $ref: '#/components/schemas/ComplexQuadrilateral'
+    SimpleQuadrilateral:
+      allOf:
+      - $ref: '#/components/schemas/ShapeInterface'
+      - $ref: '#/components/schemas/QuadrilateralInterface'
+    ComplexQuadrilateral:
+      allOf:
+      - $ref: '#/components/schemas/ShapeInterface'
+      - $ref: '#/components/schemas/QuadrilateralInterface'
+    GrandparentAnimal:
+      discriminator:
+        propertyName: pet_type
+      properties:
+        pet_type:
+          type: string
+      required:
+      - pet_type
+      type: object
+    ParentPet:
+      allOf:
+      - $ref: '#/components/schemas/GrandparentAnimal'
+      type: object
+    ChildCat:
+      allOf:
+      - $ref: '#/components/schemas/ParentPet'
+      - $ref: '#/components/schemas/ChildCat_allOf'
+    ArrayOfEnums:
+      items:
+        $ref: '#/components/schemas/OuterEnum'
+      type: array
+    DateTimeTest:
+      default: 2010-01-01T10:10:10.000111+01:00
+      example: 2010-01-01T10:10:10.000111+01:00
+      format: date-time
+      type: string
     DeprecatedObject:
       deprecated: true
       properties:
@@ -1971,20 +2134,6 @@ components:
             $ref: '#/components/schemas/Bar'
           type: array
       type: object
-    AllOfWithSingleRef:
-      properties:
-        username:
-          type: string
-        SingleRefType:
-          allOf:
-          - $ref: '#/components/schemas/SingleRefType'
-      type: object
-    SingleRefType:
-      enum:
-      - admin
-      - user
-      title: SingleRefType
-      type: string
     _foo_get_default_response:
       example:
         string:
@@ -2086,7 +2235,9 @@ components:
           format: date
           type: string
         dateTime:
+          default: 2010-02-01T10:20:10.11111+01:00
           description: None
+          example: 2020-02-02T20:20:20.22222Z
           format: date-time
           type: string
         password:
@@ -2140,6 +2291,18 @@ components:
           type: boolean
       type: object
       example: null
+    ChildCat_allOf:
+      properties:
+        name:
+          type: string
+        pet_type:
+          default: ChildCat
+          enum:
+          - ChildCat
+          type: string
+          x-enum-as-string: true
+      type: object
+      example: null
   securitySchemes:
     petstore_auth:
       flows:

samples/client/petstore/java/native-async/docs/AdditionalPropertiesClass.md

@@ -9,6 +9,12 @@
 |------------ | ------------- | ------------- | -------------|
 |**mapProperty** | **Map<String, String>** |  |  [optional] |
 |**mapOfMapProperty** | **Map<String, Map<String, String>>** |  |  [optional] |
+|**anytype1** | **Object** |  |  [optional] |
+|**mapWithUndeclaredPropertiesAnytype1** | **Object** |  |  [optional] |
+|**mapWithUndeclaredPropertiesAnytype2** | **Object** |  |  [optional] |
+|**mapWithUndeclaredPropertiesAnytype3** | **Map<String, Object>** |  |  [optional] |
+|**emptyMap** | **Object** | an object with no declared properties and no undeclared properties, hence it's an empty map. |  [optional] |
+|**mapWithUndeclaredPropertiesString** | **Map<String, String>** |  |  [optional] |
 
 
 

samples/client/petstore/java/native-async/docs/Apple.md

@@ -0,0 +1,14 @@
+
+
+# Apple
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**cultivar** | **String** |  |  [optional] |
+|**origin** | **String** |  |  [optional] |
+
+
+

samples/client/petstore/java/native-async/docs/AppleReq.md

@@ -0,0 +1,14 @@
+
+
+# AppleReq
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**cultivar** | **String** |  |  |
+|**mealy** | **Boolean** |  |  [optional] |
+
+
+

samples/client/petstore/java/native-async/docs/Banana.md

@@ -0,0 +1,13 @@
+
+
+# Banana
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**lengthCm** | **BigDecimal** |  |  [optional] |
+
+
+

samples/client/petstore/java/native-async/docs/BananaReq.md

@@ -0,0 +1,14 @@
+
+
+# BananaReq
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**lengthCm** | **BigDecimal** |  |  |
+|**sweet** | **Boolean** |  |  [optional] |
+
+
+

samples/client/petstore/java/native-async/docs/BasquePig.md

@@ -0,0 +1,13 @@
+
+
+# BasquePig
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**className** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/ChildCat.md

@@ -0,0 +1,22 @@
+
+
+# ChildCat
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**name** | **String** |  |  [optional] |
+|**petType** | [**String**](#String) |  |  [optional] |
+
+
+
+## Enum: String
+
+| Name | Value |
+|---- | -----|
+| CHILDCAT | "ChildCat" |
+
+
+

samples/client/petstore/java/native-async/docs/ChildCatAllOf.md

@@ -0,0 +1,22 @@
+
+
+# ChildCatAllOf
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**name** | **String** |  |  [optional] |
+|**petType** | [**String**](#String) |  |  [optional] |
+
+
+
+## Enum: String
+
+| Name | Value |
+|---- | -----|
+| CHILDCAT | "ChildCat" |
+
+
+

samples/client/petstore/java/native-async/docs/ComplexQuadrilateral.md

@@ -0,0 +1,14 @@
+
+
+# ComplexQuadrilateral
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+|**quadrilateralType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/DanishPig.md

@@ -0,0 +1,13 @@
+
+
+# DanishPig
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**className** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/Drawing.md

@@ -0,0 +1,16 @@
+
+
+# Drawing
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**mainShape** | [**Shape**](Shape.md) |  |  [optional] |
+|**shapeOrNull** | [**ShapeOrNull**](ShapeOrNull.md) |  |  [optional] |
+|**nullableShape** | [**NullableShape**](NullableShape.md) |  |  [optional] |
+|**shapes** | [**List<Shape>**](Shape.md) |  |  [optional] |
+
+
+

samples/client/petstore/java/native-async/docs/EnumTest.md

@@ -10,6 +10,7 @@
 |**enumString** | [**EnumStringEnum**](#EnumStringEnum) |  |  [optional] |
 |**enumStringRequired** | [**EnumStringRequiredEnum**](#EnumStringRequiredEnum) |  |  |
 |**enumInteger** | [**EnumIntegerEnum**](#EnumIntegerEnum) |  |  [optional] |
+|**enumIntegerOnly** | [**EnumIntegerOnlyEnum**](#EnumIntegerOnlyEnum) |  |  [optional] |
 |**enumNumber** | [**EnumNumberEnum**](#EnumNumberEnum) |  |  [optional] |
 |**outerEnum** | **OuterEnum** |  |  [optional] |
 |**outerEnumInteger** | **OuterEnumInteger** |  |  [optional] |
@@ -47,6 +48,15 @@
 
 
 
+## Enum: EnumIntegerOnlyEnum
+
+| Name | Value |
+|---- | -----|
+| NUMBER_2 | 2 |
+| NUMBER_MINUS_2 | -2 |
+
+
+
 ## Enum: EnumNumberEnum
 
 | Name | Value |

samples/client/petstore/java/native-async/docs/EquilateralTriangle.md

@@ -0,0 +1,14 @@
+
+
+# EquilateralTriangle
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+|**triangleType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/FakeApi.md

@@ -6,8 +6,6 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 |------------- | ------------- | -------------|
 | [**fakeHealthGet**](FakeApi.md#fakeHealthGet) | **GET** /fake/health | Health check endpoint |
 | [**fakeHealthGetWithHttpInfo**](FakeApi.md#fakeHealthGetWithHttpInfo) | **GET** /fake/health | Health check endpoint |
-| [**fakeHttpSignatureTest**](FakeApi.md#fakeHttpSignatureTest) | **GET** /fake/http-signature-test | test http signature authentication |
-| [**fakeHttpSignatureTestWithHttpInfo**](FakeApi.md#fakeHttpSignatureTestWithHttpInfo) | **GET** /fake/http-signature-test | test http signature authentication |
 | [**fakeOuterBooleanSerialize**](FakeApi.md#fakeOuterBooleanSerialize) | **POST** /fake/outer/boolean |  |
 | [**fakeOuterBooleanSerializeWithHttpInfo**](FakeApi.md#fakeOuterBooleanSerializeWithHttpInfo) | **POST** /fake/outer/boolean |  |
 | [**fakeOuterCompositeSerialize**](FakeApi.md#fakeOuterCompositeSerialize) | **POST** /fake/outer/composite |  |
@@ -16,10 +14,8 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**fakeOuterNumberSerializeWithHttpInfo**](FakeApi.md#fakeOuterNumberSerializeWithHttpInfo) | **POST** /fake/outer/number |  |
 | [**fakeOuterStringSerialize**](FakeApi.md#fakeOuterStringSerialize) | **POST** /fake/outer/string |  |
 | [**fakeOuterStringSerializeWithHttpInfo**](FakeApi.md#fakeOuterStringSerializeWithHttpInfo) | **POST** /fake/outer/string |  |
-| [**fakePropertyEnumIntegerSerialize**](FakeApi.md#fakePropertyEnumIntegerSerialize) | **POST** /fake/property/enum-int |  |
+| [**getArrayOfEnums**](FakeApi.md#getArrayOfEnums) | **GET** /fake/array-of-enums | Array of Enums |
-| [**fakePropertyEnumIntegerSerializeWithHttpInfo**](FakeApi.md#fakePropertyEnumIntegerSerializeWithHttpInfo) | **POST** /fake/property/enum-int |  |
+| [**getArrayOfEnumsWithHttpInfo**](FakeApi.md#getArrayOfEnumsWithHttpInfo) | **GET** /fake/array-of-enums | Array of Enums |
-| [**testBodyWithBinary**](FakeApi.md#testBodyWithBinary) | **PUT** /fake/body-with-binary |  |
-| [**testBodyWithBinaryWithHttpInfo**](FakeApi.md#testBodyWithBinaryWithHttpInfo) | **PUT** /fake/body-with-binary |  |
 | [**testBodyWithFileSchema**](FakeApi.md#testBodyWithFileSchema) | **PUT** /fake/body-with-file-schema |  |
 | [**testBodyWithFileSchemaWithHttpInfo**](FakeApi.md#testBodyWithFileSchemaWithHttpInfo) | **PUT** /fake/body-with-file-schema |  |
 | [**testBodyWithQueryParams**](FakeApi.md#testBodyWithQueryParams) | **PUT** /fake/body-with-query-params |  |
@@ -172,155 +168,6 @@ No authorization required
 | **200** | The instance started successfully |  -  |
 
 
-## fakeHttpSignatureTest
-
-> CompletableFuture<Void> fakeHttpSignatureTest(pet, query1, header1)
-
-test http signature authentication
-
-### Example
-
-```java
-// Import classes:
-import org.openapitools.client.ApiClient;
-import org.openapitools.client.ApiException;
-import org.openapitools.client.Configuration;
-import org.openapitools.client.auth.*;
-import org.openapitools.client.models.*;
-import org.openapitools.client.api.FakeApi;
-import java.util.concurrent.CompletableFuture;
-
-public class Example {
-    public static void main(String[] args) {
-        ApiClient defaultClient = Configuration.getDefaultApiClient();
-        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
-        
-
-        FakeApi apiInstance = new FakeApi(defaultClient);
-        Pet pet = new Pet(); // Pet | Pet object that needs to be added to the store
-        String query1 = "query1_example"; // String | query parameter
-        String header1 = "header1_example"; // String | header parameter
-        try {
-            CompletableFuture<Void> result = apiInstance.fakeHttpSignatureTest(pet, query1, header1);
-        } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#fakeHttpSignatureTest");
-            System.err.println("Status code: " + e.getCode());
-            System.err.println("Reason: " + e.getResponseBody());
-            System.err.println("Response headers: " + e.getResponseHeaders());
-            e.printStackTrace();
-        }
-    }
-}
-```
-
-### Parameters
-
-
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **pet** | [**Pet**](Pet.md)| Pet object that needs to be added to the store | |
-| **query1** | **String**| query parameter | [optional] |
-| **header1** | **String**| header parameter | [optional] |
-
-### Return type
-
-
-CompletableFuture<void> (empty response body)
-
-### Authorization
-
-[http_signature_test](../README.md#http_signature_test)
-
-### HTTP request headers
-
-- **Content-Type**: application/json, application/xml
-- **Accept**: Not defined
-
-### HTTP response details
-| Status code | Description | Response headers |
-|-------------|-------------|------------------|
-| **200** | The instance started successfully |  -  |
-
-## fakeHttpSignatureTestWithHttpInfo
-
-> CompletableFuture<ApiResponse<Void>> fakeHttpSignatureTest fakeHttpSignatureTestWithHttpInfo(pet, query1, header1)
-
-test http signature authentication
-
-### Example
-
-```java
-// Import classes:
-import org.openapitools.client.ApiClient;
-import org.openapitools.client.ApiException;
-import org.openapitools.client.ApiResponse;
-import org.openapitools.client.Configuration;
-import org.openapitools.client.auth.*;
-import org.openapitools.client.models.*;
-import org.openapitools.client.api.FakeApi;
-import java.util.concurrent.CompletableFuture;
-
-public class Example {
-    public static void main(String[] args) {
-        ApiClient defaultClient = Configuration.getDefaultApiClient();
-        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
-        
-
-        FakeApi apiInstance = new FakeApi(defaultClient);
-        Pet pet = new Pet(); // Pet | Pet object that needs to be added to the store
-        String query1 = "query1_example"; // String | query parameter
-        String header1 = "header1_example"; // String | header parameter
-        try {
-            CompletableFuture<ApiResponse<Void>> response = apiInstance.fakeHttpSignatureTestWithHttpInfo(pet, query1, header1);
-            System.out.println("Status code: " + response.get().getStatusCode());
-            System.out.println("Response headers: " + response.get().getHeaders());
-        } catch (InterruptedException | ExecutionException e) {
-            ApiException apiException = (ApiException)e.getCause();
-            System.err.println("Exception when calling FakeApi#fakeHttpSignatureTest");
-            System.err.println("Status code: " + apiException.getCode());
-            System.err.println("Response headers: " + apiException.getResponseHeaders());
-            System.err.println("Reason: " + apiException.getResponseBody());
-            e.printStackTrace();
-        } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#fakeHttpSignatureTest");
-            System.err.println("Status code: " + e.getCode());
-            System.err.println("Response headers: " + e.getResponseHeaders());
-            System.err.println("Reason: " + e.getResponseBody());
-            e.printStackTrace();
-        }
-    }
-}
-```
-
-### Parameters
-
-
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **pet** | [**Pet**](Pet.md)| Pet object that needs to be added to the store | |
-| **query1** | **String**| query parameter | [optional] |
-| **header1** | **String**| header parameter | [optional] |
-
-### Return type
-
-
-CompletableFuture<ApiResponse<Void>>
-
-### Authorization
-
-[http_signature_test](../README.md#http_signature_test)
-
-### HTTP request headers
-
-- **Content-Type**: application/json, application/xml
-- **Accept**: Not defined
-
-### HTTP response details
-| Status code | Description | Response headers |
-|-------------|-------------|------------------|
-| **200** | The instance started successfully |  -  |
-
-
 ## fakeOuterBooleanSerialize
 
 > CompletableFuture<Boolean> fakeOuterBooleanSerialize(body)
@@ -893,13 +740,11 @@ No authorization required
 | **200** | Output string |  -  |
 
 
-## fakePropertyEnumIntegerSerialize
+## getArrayOfEnums
 
-> CompletableFuture<OuterObjectWithEnumProperty> fakePropertyEnumIntegerSerialize(outerObjectWithEnumProperty)
+> CompletableFuture<List<OuterEnum>> getArrayOfEnums()
 
-
+Array of Enums
-
-Test serialization of enum (int) properties with examples
 
 ### Example
 
@@ -918,12 +763,11 @@ public class Example {
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
 
         FakeApi apiInstance = new FakeApi(defaultClient);
-        OuterObjectWithEnumProperty outerObjectWithEnumProperty = new OuterObjectWithEnumProperty(); // OuterObjectWithEnumProperty | Input enum (int) as post body
         try {
-            CompletableFuture<OuterObjectWithEnumProperty> result = apiInstance.fakePropertyEnumIntegerSerialize(outerObjectWithEnumProperty);
+            CompletableFuture<List<OuterEnum>> result = apiInstance.getArrayOfEnums();
             System.out.println(result.get());
         } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#fakePropertyEnumIntegerSerialize");
+            System.err.println("Exception when calling FakeApi#getArrayOfEnums");
             System.err.println("Status code: " + e.getCode());
             System.err.println("Reason: " + e.getResponseBody());
             System.err.println("Response headers: " + e.getResponseHeaders());
@@ -935,14 +779,11 @@ public class Example {
 
 ### Parameters
 
-
+This endpoint does not need any parameter.
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **outerObjectWithEnumProperty** | [**OuterObjectWithEnumProperty**](OuterObjectWithEnumProperty.md)| Input enum (int) as post body | |
 
 ### Return type
 
-CompletableFuture<[**OuterObjectWithEnumProperty**](OuterObjectWithEnumProperty.md)>
+CompletableFuture<[**List&lt;OuterEnum&gt;**](OuterEnum.md)>
 
 
 ### Authorization
@@ -951,21 +792,19 @@ No authorization required
 
 ### HTTP request headers
 
-- **Content-Type**: application/json
+- **Content-Type**: Not defined
-- **Accept**: */*
+- **Accept**: application/json
 
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Output enum (int) |  -  |
+| **200** | Got named array of enums |  -  |
 
-## fakePropertyEnumIntegerSerializeWithHttpInfo
+## getArrayOfEnumsWithHttpInfo
 
-> CompletableFuture<ApiResponse<OuterObjectWithEnumProperty>> fakePropertyEnumIntegerSerialize fakePropertyEnumIntegerSerializeWithHttpInfo(outerObjectWithEnumProperty)
+> CompletableFuture<ApiResponse<List<OuterEnum>>> getArrayOfEnums getArrayOfEnumsWithHttpInfo()
 
-
+Array of Enums
-
-Test serialization of enum (int) properties with examples
 
 ### Example
 
@@ -985,21 +824,20 @@ public class Example {
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
 
         FakeApi apiInstance = new FakeApi(defaultClient);
-        OuterObjectWithEnumProperty outerObjectWithEnumProperty = new OuterObjectWithEnumProperty(); // OuterObjectWithEnumProperty | Input enum (int) as post body
         try {
-            CompletableFuture<ApiResponse<OuterObjectWithEnumProperty>> response = apiInstance.fakePropertyEnumIntegerSerializeWithHttpInfo(outerObjectWithEnumProperty);
+            CompletableFuture<ApiResponse<List<OuterEnum>>> response = apiInstance.getArrayOfEnumsWithHttpInfo();
             System.out.println("Status code: " + response.get().getStatusCode());
             System.out.println("Response headers: " + response.get().getHeaders());
             System.out.println("Response body: " + response.get().getData());
         } catch (InterruptedException | ExecutionException e) {
             ApiException apiException = (ApiException)e.getCause();
-            System.err.println("Exception when calling FakeApi#fakePropertyEnumIntegerSerialize");
+            System.err.println("Exception when calling FakeApi#getArrayOfEnums");
             System.err.println("Status code: " + apiException.getCode());
             System.err.println("Response headers: " + apiException.getResponseHeaders());
             System.err.println("Reason: " + apiException.getResponseBody());
             e.printStackTrace();
         } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#fakePropertyEnumIntegerSerialize");
+            System.err.println("Exception when calling FakeApi#getArrayOfEnums");
             System.err.println("Status code: " + e.getCode());
             System.err.println("Response headers: " + e.getResponseHeaders());
             System.err.println("Reason: " + e.getResponseBody());
@@ -1011,14 +849,11 @@ public class Example {
 
 ### Parameters
 
-
+This endpoint does not need any parameter.
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **outerObjectWithEnumProperty** | [**OuterObjectWithEnumProperty**](OuterObjectWithEnumProperty.md)| Input enum (int) as post body | |
 
 ### Return type
 
-CompletableFuture<ApiResponse<[**OuterObjectWithEnumProperty**](OuterObjectWithEnumProperty.md)>>
+CompletableFuture<ApiResponse<[**List&lt;OuterEnum&gt;**](OuterEnum.md)>>
 
 
 ### Authorization
@@ -1027,154 +862,13 @@ No authorization required
 
 ### HTTP request headers
 
-- **Content-Type**: application/json
+- **Content-Type**: Not defined
-- **Accept**: */*
+- **Accept**: application/json
 
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Output enum (int) |  -  |
+| **200** | Got named array of enums |  -  |
-
-
-## testBodyWithBinary
-
-> CompletableFuture<Void> testBodyWithBinary(body)
-
-
-
-For this test, the body has to be a binary file.
-
-### Example
-
-```java
-// Import classes:
-import org.openapitools.client.ApiClient;
-import org.openapitools.client.ApiException;
-import org.openapitools.client.Configuration;
-import org.openapitools.client.models.*;
-import org.openapitools.client.api.FakeApi;
-import java.util.concurrent.CompletableFuture;
-
-public class Example {
-    public static void main(String[] args) {
-        ApiClient defaultClient = Configuration.getDefaultApiClient();
-        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
-
-        FakeApi apiInstance = new FakeApi(defaultClient);
-        File body = new File("/path/to/file"); // File | image to upload
-        try {
-            CompletableFuture<Void> result = apiInstance.testBodyWithBinary(body);
-        } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#testBodyWithBinary");
-            System.err.println("Status code: " + e.getCode());
-            System.err.println("Reason: " + e.getResponseBody());
-            System.err.println("Response headers: " + e.getResponseHeaders());
-            e.printStackTrace();
-        }
-    }
-}
-```
-
-### Parameters
-
-
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **body** | **File**| image to upload | |
-
-### Return type
-
-
-CompletableFuture<void> (empty response body)
-
-### Authorization
-
-No authorization required
-
-### HTTP request headers
-
-- **Content-Type**: image/png
-- **Accept**: Not defined
-
-### HTTP response details
-| Status code | Description | Response headers |
-|-------------|-------------|------------------|
-| **200** | Success |  -  |
-
-## testBodyWithBinaryWithHttpInfo
-
-> CompletableFuture<ApiResponse<Void>> testBodyWithBinary testBodyWithBinaryWithHttpInfo(body)
-
-
-
-For this test, the body has to be a binary file.
-
-### Example
-
-```java
-// Import classes:
-import org.openapitools.client.ApiClient;
-import org.openapitools.client.ApiException;
-import org.openapitools.client.ApiResponse;
-import org.openapitools.client.Configuration;
-import org.openapitools.client.models.*;
-import org.openapitools.client.api.FakeApi;
-import java.util.concurrent.CompletableFuture;
-
-public class Example {
-    public static void main(String[] args) {
-        ApiClient defaultClient = Configuration.getDefaultApiClient();
-        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
-
-        FakeApi apiInstance = new FakeApi(defaultClient);
-        File body = new File("/path/to/file"); // File | image to upload
-        try {
-            CompletableFuture<ApiResponse<Void>> response = apiInstance.testBodyWithBinaryWithHttpInfo(body);
-            System.out.println("Status code: " + response.get().getStatusCode());
-            System.out.println("Response headers: " + response.get().getHeaders());
-        } catch (InterruptedException | ExecutionException e) {
-            ApiException apiException = (ApiException)e.getCause();
-            System.err.println("Exception when calling FakeApi#testBodyWithBinary");
-            System.err.println("Status code: " + apiException.getCode());
-            System.err.println("Response headers: " + apiException.getResponseHeaders());
-            System.err.println("Reason: " + apiException.getResponseBody());
-            e.printStackTrace();
-        } catch (ApiException e) {
-            System.err.println("Exception when calling FakeApi#testBodyWithBinary");
-            System.err.println("Status code: " + e.getCode());
-            System.err.println("Response headers: " + e.getResponseHeaders());
-            System.err.println("Reason: " + e.getResponseBody());
-            e.printStackTrace();
-        }
-    }
-}
-```
-
-### Parameters
-
-
-| Name | Type | Description  | Notes |
-|------------- | ------------- | ------------- | -------------|
-| **body** | **File**| image to upload | |
-
-### Return type
-
-
-CompletableFuture<ApiResponse<Void>>
-
-### Authorization
-
-No authorization required
-
-### HTTP request headers
-
-- **Content-Type**: image/png
-- **Accept**: Not defined
-
-### HTTP response details
-| Status code | Description | Response headers |
-|-------------|-------------|------------------|
-| **200** | Success |  -  |
 
 
 ## testBodyWithFileSchema
@@ -1183,7 +877,7 @@ No authorization required
 
 
 
-For this test, the body for this request must reference a schema named &#x60;File&#x60;.
+For this test, the body for this request much reference a schema named &#x60;File&#x60;.
 
 ### Example
 
@@ -1248,7 +942,7 @@ No authorization required
 
 
 
-For this test, the body for this request must reference a schema named &#x60;File&#x60;.
+For this test, the body for this request much reference a schema named &#x60;File&#x60;.
 
 ### Example
 
@@ -1644,7 +1338,7 @@ public class Example {
         String string = "string_example"; // String | None
         File binary = new File("/path/to/file"); // File | None
         LocalDate date = LocalDate.now(); // LocalDate | None
-        OffsetDateTime dateTime = OffsetDateTime.now(); // OffsetDateTime | None
+        OffsetDateTime dateTime = OffsetDateTime.parse("2010-02-01T10:20:10.111110+01:00"); // OffsetDateTime | None
         String password = "password_example"; // String | None
         String paramCallback = "paramCallback_example"; // String | None
         try {
@@ -1676,7 +1370,7 @@ public class Example {
 | **string** | **String**| None | [optional] |
 | **binary** | **File**| None | [optional] |
 | **date** | **LocalDate**| None | [optional] |
-| **dateTime** | **OffsetDateTime**| None | [optional] |
+| **dateTime** | **OffsetDateTime**| None | [optional] [default to 2010-02-01T10:20:10.111110+01:00] |
 | **password** | **String**| None | [optional] |
 | **paramCallback** | **String**| None | [optional] |
 
@@ -1743,7 +1437,7 @@ public class Example {
         String string = "string_example"; // String | None
         File binary = new File("/path/to/file"); // File | None
         LocalDate date = LocalDate.now(); // LocalDate | None
-        OffsetDateTime dateTime = OffsetDateTime.now(); // OffsetDateTime | None
+        OffsetDateTime dateTime = OffsetDateTime.parse("2010-02-01T10:20:10.111110+01:00"); // OffsetDateTime | None
         String password = "password_example"; // String | None
         String paramCallback = "paramCallback_example"; // String | None
         try {
@@ -1784,7 +1478,7 @@ public class Example {
 | **string** | **String**| None | [optional] |
 | **binary** | **File**| None | [optional] |
 | **date** | **LocalDate**| None | [optional] |
-| **dateTime** | **OffsetDateTime**| None | [optional] |
+| **dateTime** | **OffsetDateTime**| None | [optional] [default to 2010-02-01T10:20:10.111110+01:00] |
 | **password** | **String**| None | [optional] |
 | **paramCallback** | **String**| None | [optional] |
 
@@ -1811,7 +1505,7 @@ CompletableFuture<ApiResponse<Void>>
 
 ## testEnumParameters
 
-> CompletableFuture<Void> testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString)
+> CompletableFuture<Void> testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString)
 
 To test enum parameters
 
@@ -1840,11 +1534,10 @@ public class Example {
         String enumQueryString = "_abc"; // String | Query parameter enum test (string)
         Integer enumQueryInteger = 1; // Integer | Query parameter enum test (double)
         Double enumQueryDouble = 1.1D; // Double | Query parameter enum test (double)
-        List<EnumClass> enumQueryModelArray = Arrays.asList(-efg); // List<EnumClass> | 
         List<String> enumFormStringArray = Arrays.asList("$"); // List<String> | Form parameter enum test (string array)
         String enumFormString = "_abc"; // String | Form parameter enum test (string)
         try {
-            CompletableFuture<Void> result = apiInstance.testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString);
+            CompletableFuture<Void> result = apiInstance.testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString);
         } catch (ApiException e) {
             System.err.println("Exception when calling FakeApi#testEnumParameters");
             System.err.println("Status code: " + e.getCode());
@@ -1867,7 +1560,6 @@ public class Example {
 | **enumQueryString** | **String**| Query parameter enum test (string) | [optional] [default to -efg] [enum: _abc, -efg, (xyz)] |
 | **enumQueryInteger** | **Integer**| Query parameter enum test (double) | [optional] [enum: 1, -2] |
 | **enumQueryDouble** | **Double**| Query parameter enum test (double) | [optional] [enum: 1.1, -1.2] |
-| **enumQueryModelArray** | [**List&lt;EnumClass&gt;**](EnumClass.md)|  | [optional] |
 | **enumFormStringArray** | [**List&lt;String&gt;**](String.md)| Form parameter enum test (string array) | [optional] [enum: >, $] |
 | **enumFormString** | **String**| Form parameter enum test (string) | [optional] [default to -efg] [enum: _abc, -efg, (xyz)] |
 
@@ -1893,7 +1585,7 @@ No authorization required
 
 ## testEnumParametersWithHttpInfo
 
-> CompletableFuture<ApiResponse<Void>> testEnumParameters testEnumParametersWithHttpInfo(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString)
+> CompletableFuture<ApiResponse<Void>> testEnumParameters testEnumParametersWithHttpInfo(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString)
 
 To test enum parameters
 
@@ -1923,11 +1615,10 @@ public class Example {
         String enumQueryString = "_abc"; // String | Query parameter enum test (string)
         Integer enumQueryInteger = 1; // Integer | Query parameter enum test (double)
         Double enumQueryDouble = 1.1D; // Double | Query parameter enum test (double)
-        List<EnumClass> enumQueryModelArray = Arrays.asList(-efg); // List<EnumClass> | 
         List<String> enumFormStringArray = Arrays.asList("$"); // List<String> | Form parameter enum test (string array)
         String enumFormString = "_abc"; // String | Form parameter enum test (string)
         try {
-            CompletableFuture<ApiResponse<Void>> response = apiInstance.testEnumParametersWithHttpInfo(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString);
+            CompletableFuture<ApiResponse<Void>> response = apiInstance.testEnumParametersWithHttpInfo(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString);
             System.out.println("Status code: " + response.get().getStatusCode());
             System.out.println("Response headers: " + response.get().getHeaders());
         } catch (InterruptedException | ExecutionException e) {
@@ -1959,7 +1650,6 @@ public class Example {
 | **enumQueryString** | **String**| Query parameter enum test (string) | [optional] [default to -efg] [enum: _abc, -efg, (xyz)] |
 | **enumQueryInteger** | **Integer**| Query parameter enum test (double) | [optional] [enum: 1, -2] |
 | **enumQueryDouble** | **Double**| Query parameter enum test (double) | [optional] [enum: 1.1, -1.2] |
-| **enumQueryModelArray** | [**List&lt;EnumClass&gt;**](EnumClass.md)|  | [optional] |
 | **enumFormStringArray** | [**List&lt;String&gt;**](String.md)| Form parameter enum test (string array) | [optional] [enum: >, $] |
 | **enumFormString** | **String**| Form parameter enum test (string) | [optional] [default to -efg] [enum: _abc, -efg, (xyz)] |
 
@@ -2464,7 +2154,7 @@ No authorization required
 
 ## testQueryParameterCollectionFormat
 
-> CompletableFuture<Void> testQueryParameterCollectionFormat(pipe, ioutil, http, url, context, allowEmpty, language)
+> CompletableFuture<Void> testQueryParameterCollectionFormat(pipe, ioutil, http, url, context)
 
 
 
@@ -2492,10 +2182,8 @@ public class Example {
         List<String> http = Arrays.asList(); // List<String> | 
         List<String> url = Arrays.asList(); // List<String> | 
         List<String> context = Arrays.asList(); // List<String> | 
-        String allowEmpty = "allowEmpty_example"; // String | 
-        Map<String, String> language = new HashMap(); // Map<String, String> | 
         try {
-            CompletableFuture<Void> result = apiInstance.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context, allowEmpty, language);
+            CompletableFuture<Void> result = apiInstance.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context);
         } catch (ApiException e) {
             System.err.println("Exception when calling FakeApi#testQueryParameterCollectionFormat");
             System.err.println("Status code: " + e.getCode());
@@ -2517,8 +2205,6 @@ public class Example {
 | **http** | [**List&lt;String&gt;**](String.md)|  | |
 | **url** | [**List&lt;String&gt;**](String.md)|  | |
 | **context** | [**List&lt;String&gt;**](String.md)|  | |
-| **allowEmpty** | **String**|  | |
-| **language** | [**Map&lt;String, String&gt;**](String.md)|  | [optional] |
 
 ### Return type
 
@@ -2541,7 +2227,7 @@ No authorization required
 
 ## testQueryParameterCollectionFormatWithHttpInfo
 
-> CompletableFuture<ApiResponse<Void>> testQueryParameterCollectionFormat testQueryParameterCollectionFormatWithHttpInfo(pipe, ioutil, http, url, context, allowEmpty, language)
+> CompletableFuture<ApiResponse<Void>> testQueryParameterCollectionFormat testQueryParameterCollectionFormatWithHttpInfo(pipe, ioutil, http, url, context)
 
 
 
@@ -2570,10 +2256,8 @@ public class Example {
         List<String> http = Arrays.asList(); // List<String> | 
         List<String> url = Arrays.asList(); // List<String> | 
         List<String> context = Arrays.asList(); // List<String> | 
-        String allowEmpty = "allowEmpty_example"; // String | 
-        Map<String, String> language = new HashMap(); // Map<String, String> | 
         try {
-            CompletableFuture<ApiResponse<Void>> response = apiInstance.testQueryParameterCollectionFormatWithHttpInfo(pipe, ioutil, http, url, context, allowEmpty, language);
+            CompletableFuture<ApiResponse<Void>> response = apiInstance.testQueryParameterCollectionFormatWithHttpInfo(pipe, ioutil, http, url, context);
             System.out.println("Status code: " + response.get().getStatusCode());
             System.out.println("Response headers: " + response.get().getHeaders());
         } catch (InterruptedException | ExecutionException e) {
@@ -2604,8 +2288,6 @@ public class Example {
 | **http** | [**List&lt;String&gt;**](String.md)|  | |
 | **url** | [**List&lt;String&gt;**](String.md)|  | |
 | **context** | [**List&lt;String&gt;**](String.md)|  | |
-| **allowEmpty** | **String**|  | |
-| **language** | [**Map&lt;String, String&gt;**](String.md)|  | [optional] |
 
 ### Return type
 

samples/client/petstore/java/native-async/docs/Fruit.md

@@ -0,0 +1,37 @@
+
+
+# Fruit
+
+## oneOf schemas
+* [Apple](Apple.md)
+* [Banana](Banana.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Fruit;
+import org.openapitools.client.model.Apple;
+import org.openapitools.client.model.Banana;
+
+public class Example {
+    public static void main(String[] args) {
+        Fruit exampleFruit = new Fruit();
+
+        // create a new Apple
+        Apple exampleApple = new Apple();
+        // set Fruit to Apple
+        exampleFruit.setActualInstance(exampleApple);
+        // to get back the Apple set earlier
+        Apple testApple = (Apple) exampleFruit.getActualInstance();
+
+        // create a new Banana
+        Banana exampleBanana = new Banana();
+        // set Fruit to Banana
+        exampleFruit.setActualInstance(exampleBanana);
+        // to get back the Banana set earlier
+        Banana testBanana = (Banana) exampleFruit.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/FruitReq.md

@@ -0,0 +1,37 @@
+
+
+# FruitReq
+
+## oneOf schemas
+* [AppleReq](AppleReq.md)
+* [BananaReq](BananaReq.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.FruitReq;
+import org.openapitools.client.model.AppleReq;
+import org.openapitools.client.model.BananaReq;
+
+public class Example {
+    public static void main(String[] args) {
+        FruitReq exampleFruitReq = new FruitReq();
+
+        // create a new AppleReq
+        AppleReq exampleAppleReq = new AppleReq();
+        // set FruitReq to AppleReq
+        exampleFruitReq.setActualInstance(exampleAppleReq);
+        // to get back the AppleReq set earlier
+        AppleReq testAppleReq = (AppleReq) exampleFruitReq.getActualInstance();
+
+        // create a new BananaReq
+        BananaReq exampleBananaReq = new BananaReq();
+        // set FruitReq to BananaReq
+        exampleFruitReq.setActualInstance(exampleBananaReq);
+        // to get back the BananaReq set earlier
+        BananaReq testBananaReq = (BananaReq) exampleFruitReq.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/GmFruit.md

@@ -0,0 +1,37 @@
+
+
+# GmFruit
+
+## anyOf schemas
+* [Apple](Apple.md)
+* [Banana](Banana.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.GmFruit;
+import org.openapitools.client.model.Apple;
+import org.openapitools.client.model.Banana;
+
+public class Example {
+    public static void main(String[] args) {
+        GmFruit exampleGmFruit = new GmFruit();
+
+        // create a new Apple
+        Apple exampleApple = new Apple();
+        // set GmFruit to Apple
+        exampleGmFruit.setActualInstance(exampleApple);
+        // to get back the Apple set earlier
+        Apple testApple = (Apple) exampleGmFruit.getActualInstance();
+
+        // create a new Banana
+        Banana exampleBanana = new Banana();
+        // set GmFruit to Banana
+        exampleGmFruit.setActualInstance(exampleBanana);
+        // to get back the Banana set earlier
+        Banana testBanana = (Banana) exampleGmFruit.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/GrandparentAnimal.md

@@ -0,0 +1,13 @@
+
+
+# GrandparentAnimal
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**petType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/IsoscelesTriangle.md

@@ -0,0 +1,14 @@
+
+
+# IsoscelesTriangle
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+|**triangleType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/Mammal.md

@@ -0,0 +1,46 @@
+
+
+# Mammal
+
+## oneOf schemas
+* [Pig](Pig.md)
+* [Whale](Whale.md)
+* [Zebra](Zebra.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Mammal;
+import org.openapitools.client.model.Pig;
+import org.openapitools.client.model.Whale;
+import org.openapitools.client.model.Zebra;
+
+public class Example {
+    public static void main(String[] args) {
+        Mammal exampleMammal = new Mammal();
+
+        // create a new Pig
+        Pig examplePig = new Pig();
+        // set Mammal to Pig
+        exampleMammal.setActualInstance(examplePig);
+        // to get back the Pig set earlier
+        Pig testPig = (Pig) exampleMammal.getActualInstance();
+
+        // create a new Whale
+        Whale exampleWhale = new Whale();
+        // set Mammal to Whale
+        exampleMammal.setActualInstance(exampleWhale);
+        // to get back the Whale set earlier
+        Whale testWhale = (Whale) exampleMammal.getActualInstance();
+
+        // create a new Zebra
+        Zebra exampleZebra = new Zebra();
+        // set Mammal to Zebra
+        exampleMammal.setActualInstance(exampleZebra);
+        // to get back the Zebra set earlier
+        Zebra testZebra = (Zebra) exampleMammal.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/NullableShape.md

@@ -0,0 +1,41 @@
+
+
+# NullableShape
+
+The value may be a shape or the 'null' value. The 'nullable' attribute was introduced in OAS schema >= 3.0 and has been deprecated in OAS schema >= 3.1.
+
+## oneOf schemas
+* [Quadrilateral](Quadrilateral.md)
+* [Triangle](Triangle.md)
+
+NOTE: this class is nullable.
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.NullableShape;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+
+public class Example {
+    public static void main(String[] args) {
+        NullableShape exampleNullableShape = new NullableShape();
+
+        // create a new Quadrilateral
+        Quadrilateral exampleQuadrilateral = new Quadrilateral();
+        // set NullableShape to Quadrilateral
+        exampleNullableShape.setActualInstance(exampleQuadrilateral);
+        // to get back the Quadrilateral set earlier
+        Quadrilateral testQuadrilateral = (Quadrilateral) exampleNullableShape.getActualInstance();
+
+        // create a new Triangle
+        Triangle exampleTriangle = new Triangle();
+        // set NullableShape to Triangle
+        exampleNullableShape.setActualInstance(exampleTriangle);
+        // to get back the Triangle set earlier
+        Triangle testTriangle = (Triangle) exampleNullableShape.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/ParentPet.md

@@ -0,0 +1,12 @@
+
+
+# ParentPet
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+
+
+

samples/client/petstore/java/native-async/docs/Pet.md

@@ -10,7 +10,7 @@
 |**id** | **Long** |  |  [optional] |
 |**category** | [**Category**](Category.md) |  |  [optional] |
 |**name** | **String** |  |  |
-|**photoUrls** | **Set<String>** |  |  |
+|**photoUrls** | **List<String>** |  |  |
 |**tags** | [**List<Tag>**](Tag.md) |  |  [optional] |
 |**status** | [**StatusEnum**](#StatusEnum) | pet status in the store |  [optional] |
 

samples/client/petstore/java/native-async/docs/PetApi.md

@@ -50,6 +50,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -83,7 +84,7 @@ CompletableFuture<void> (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -93,7 +94,6 @@ CompletableFuture<void> (empty response body)
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **405** | Invalid input |  -  |
 
 ## addPetWithHttpInfo
@@ -122,6 +122,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -164,7 +165,7 @@ CompletableFuture<ApiResponse<Void>>
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -174,7 +175,6 @@ CompletableFuture<ApiResponse<Void>>
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **405** | Invalid input |  -  |
 
 
@@ -248,7 +248,6 @@ CompletableFuture<void> (empty response body)
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **400** | Invalid pet value |  -  |
 
 ## deletePetWithHttpInfo
@@ -331,7 +330,6 @@ CompletableFuture<ApiResponse<Void>>
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **400** | Invalid pet value |  -  |
 
 
@@ -360,6 +358,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -394,7 +393,7 @@ CompletableFuture<[**List&lt;Pet&gt;**](Pet.md)>
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -433,6 +432,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -476,7 +476,7 @@ CompletableFuture<ApiResponse<[**List&lt;Pet&gt;**](Pet.md)>>
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -492,7 +492,7 @@ CompletableFuture<ApiResponse<[**List&lt;Pet&gt;**](Pet.md)>>
 
 ## findPetsByTags
 
-> CompletableFuture<Set<Pet>> findPetsByTags(tags)
+> CompletableFuture<List<Pet>> findPetsByTags(tags)
 
 Finds Pets by tags
 
@@ -515,14 +515,15 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
 
         PetApi apiInstance = new PetApi(defaultClient);
-        Set<String> tags = Arrays.asList(); // Set<String> | Tags to filter by
+        List<String> tags = Arrays.asList(); // List<String> | Tags to filter by
         try {
-            CompletableFuture<Set<Pet>> result = apiInstance.findPetsByTags(tags);
+            CompletableFuture<List<Pet>> result = apiInstance.findPetsByTags(tags);
             System.out.println(result.get());
         } catch (ApiException e) {
             System.err.println("Exception when calling PetApi#findPetsByTags");
@@ -540,16 +541,16 @@ public class Example {
 
 | Name | Type | Description  | Notes |
 |------------- | ------------- | ------------- | -------------|
-| **tags** | [**Set&lt;String&gt;**](String.md)| Tags to filter by | |
+| **tags** | [**List&lt;String&gt;**](String.md)| Tags to filter by | |
 
 ### Return type
 
-CompletableFuture<[**Set&lt;Pet&gt;**](Pet.md)>
+CompletableFuture<[**List&lt;Pet&gt;**](Pet.md)>
 
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -564,7 +565,7 @@ CompletableFuture<[**Set&lt;Pet&gt;**](Pet.md)>
 
 ## findPetsByTagsWithHttpInfo
 
-> CompletableFuture<ApiResponse<Set<Pet>>> findPetsByTags findPetsByTagsWithHttpInfo(tags)
+> CompletableFuture<ApiResponse<List<Pet>>> findPetsByTags findPetsByTagsWithHttpInfo(tags)
 
 Finds Pets by tags
 
@@ -588,14 +589,15 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
 
         PetApi apiInstance = new PetApi(defaultClient);
-        Set<String> tags = Arrays.asList(); // Set<String> | Tags to filter by
+        List<String> tags = Arrays.asList(); // List<String> | Tags to filter by
         try {
-            CompletableFuture<ApiResponse<Set<Pet>>> response = apiInstance.findPetsByTagsWithHttpInfo(tags);
+            CompletableFuture<ApiResponse<List<Pet>>> response = apiInstance.findPetsByTagsWithHttpInfo(tags);
             System.out.println("Status code: " + response.get().getStatusCode());
             System.out.println("Response headers: " + response.get().getHeaders());
             System.out.println("Response body: " + response.get().getData());
@@ -622,16 +624,16 @@ public class Example {
 
 | Name | Type | Description  | Notes |
 |------------- | ------------- | ------------- | -------------|
-| **tags** | [**Set&lt;String&gt;**](String.md)| Tags to filter by | |
+| **tags** | [**List&lt;String&gt;**](String.md)| Tags to filter by | |
 
 ### Return type
 
-CompletableFuture<ApiResponse<[**Set&lt;Pet&gt;**](Pet.md)>>
+CompletableFuture<ApiResponse<[**List&lt;Pet&gt;**](Pet.md)>>
 
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -831,6 +833,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -864,7 +867,7 @@ CompletableFuture<void> (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -874,7 +877,6 @@ CompletableFuture<void> (empty response body)
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **400** | Invalid ID supplied |  -  |
 | **404** | Pet not found |  -  |
 | **405** | Validation exception |  -  |
@@ -905,6 +907,7 @@ public class Example {
         ApiClient defaultClient = Configuration.getDefaultApiClient();
         defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
         
+
         // Configure OAuth2 access token for authorization: petstore_auth
         OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
         petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
@@ -947,7 +950,7 @@ CompletableFuture<ApiResponse<Void>>
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+[http_signature_test](../README.md#http_signature_test), [petstore_auth](../README.md#petstore_auth)
 
 ### HTTP request headers
 
@@ -957,7 +960,6 @@ CompletableFuture<ApiResponse<Void>>
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **400** | Invalid ID supplied |  -  |
 | **404** | Pet not found |  -  |
 | **405** | Validation exception |  -  |
@@ -1035,7 +1037,6 @@ CompletableFuture<void> (empty response body)
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **405** | Invalid input |  -  |
 
 ## updatePetWithFormWithHttpInfo
@@ -1120,7 +1121,6 @@ CompletableFuture<ApiResponse<Void>>
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
-| **200** | Successful operation |  -  |
 | **405** | Invalid input |  -  |
 
 

samples/client/petstore/java/native-async/docs/Pig.md

@@ -0,0 +1,37 @@
+
+
+# Pig
+
+## oneOf schemas
+* [BasquePig](BasquePig.md)
+* [DanishPig](DanishPig.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Pig;
+import org.openapitools.client.model.BasquePig;
+import org.openapitools.client.model.DanishPig;
+
+public class Example {
+    public static void main(String[] args) {
+        Pig examplePig = new Pig();
+
+        // create a new BasquePig
+        BasquePig exampleBasquePig = new BasquePig();
+        // set Pig to BasquePig
+        examplePig.setActualInstance(exampleBasquePig);
+        // to get back the BasquePig set earlier
+        BasquePig testBasquePig = (BasquePig) examplePig.getActualInstance();
+
+        // create a new DanishPig
+        DanishPig exampleDanishPig = new DanishPig();
+        // set Pig to DanishPig
+        examplePig.setActualInstance(exampleDanishPig);
+        // to get back the DanishPig set earlier
+        DanishPig testDanishPig = (DanishPig) examplePig.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/Quadrilateral.md

@@ -0,0 +1,37 @@
+
+
+# Quadrilateral
+
+## oneOf schemas
+* [ComplexQuadrilateral](ComplexQuadrilateral.md)
+* [SimpleQuadrilateral](SimpleQuadrilateral.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.ComplexQuadrilateral;
+import org.openapitools.client.model.SimpleQuadrilateral;
+
+public class Example {
+    public static void main(String[] args) {
+        Quadrilateral exampleQuadrilateral = new Quadrilateral();
+
+        // create a new ComplexQuadrilateral
+        ComplexQuadrilateral exampleComplexQuadrilateral = new ComplexQuadrilateral();
+        // set Quadrilateral to ComplexQuadrilateral
+        exampleQuadrilateral.setActualInstance(exampleComplexQuadrilateral);
+        // to get back the ComplexQuadrilateral set earlier
+        ComplexQuadrilateral testComplexQuadrilateral = (ComplexQuadrilateral) exampleQuadrilateral.getActualInstance();
+
+        // create a new SimpleQuadrilateral
+        SimpleQuadrilateral exampleSimpleQuadrilateral = new SimpleQuadrilateral();
+        // set Quadrilateral to SimpleQuadrilateral
+        exampleQuadrilateral.setActualInstance(exampleSimpleQuadrilateral);
+        // to get back the SimpleQuadrilateral set earlier
+        SimpleQuadrilateral testSimpleQuadrilateral = (SimpleQuadrilateral) exampleQuadrilateral.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/QuadrilateralInterface.md

@@ -0,0 +1,13 @@
+
+
+# QuadrilateralInterface
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**quadrilateralType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/ScaleneTriangle.md

@@ -0,0 +1,14 @@
+
+
+# ScaleneTriangle
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+|**triangleType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/Shape.md

@@ -0,0 +1,37 @@
+
+
+# Shape
+
+## oneOf schemas
+* [Quadrilateral](Quadrilateral.md)
+* [Triangle](Triangle.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Shape;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+
+public class Example {
+    public static void main(String[] args) {
+        Shape exampleShape = new Shape();
+
+        // create a new Quadrilateral
+        Quadrilateral exampleQuadrilateral = new Quadrilateral();
+        // set Shape to Quadrilateral
+        exampleShape.setActualInstance(exampleQuadrilateral);
+        // to get back the Quadrilateral set earlier
+        Quadrilateral testQuadrilateral = (Quadrilateral) exampleShape.getActualInstance();
+
+        // create a new Triangle
+        Triangle exampleTriangle = new Triangle();
+        // set Shape to Triangle
+        exampleShape.setActualInstance(exampleTriangle);
+        // to get back the Triangle set earlier
+        Triangle testTriangle = (Triangle) exampleShape.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/ShapeInterface.md

@@ -0,0 +1,13 @@
+
+
+# ShapeInterface
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/ShapeOrNull.md

@@ -0,0 +1,39 @@
+
+
+# ShapeOrNull
+
+The value may be a shape or the 'null' value. This is introduced in OAS schema >= 3.1.
+
+## oneOf schemas
+* [Quadrilateral](Quadrilateral.md)
+* [Triangle](Triangle.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.ShapeOrNull;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+
+public class Example {
+    public static void main(String[] args) {
+        ShapeOrNull exampleShapeOrNull = new ShapeOrNull();
+
+        // create a new Quadrilateral
+        Quadrilateral exampleQuadrilateral = new Quadrilateral();
+        // set ShapeOrNull to Quadrilateral
+        exampleShapeOrNull.setActualInstance(exampleQuadrilateral);
+        // to get back the Quadrilateral set earlier
+        Quadrilateral testQuadrilateral = (Quadrilateral) exampleShapeOrNull.getActualInstance();
+
+        // create a new Triangle
+        Triangle exampleTriangle = new Triangle();
+        // set ShapeOrNull to Triangle
+        exampleShapeOrNull.setActualInstance(exampleTriangle);
+        // to get back the Triangle set earlier
+        Triangle testTriangle = (Triangle) exampleShapeOrNull.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/SimpleQuadrilateral.md

@@ -0,0 +1,14 @@
+
+
+# SimpleQuadrilateral
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**shapeType** | **String** |  |  |
+|**quadrilateralType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/SpecialModelName.md

@@ -8,6 +8,7 @@
 | Name | Type | Description | Notes |
 |------------ | ------------- | ------------- | -------------|
 |**$specialPropertyName** | **Long** |  |  [optional] |
+|**specialModelName** | **String** |  |  [optional] |
 
 
 

samples/client/petstore/java/native-async/docs/Triangle.md

@@ -0,0 +1,46 @@
+
+
+# Triangle
+
+## oneOf schemas
+* [EquilateralTriangle](EquilateralTriangle.md)
+* [IsoscelesTriangle](IsoscelesTriangle.md)
+* [ScaleneTriangle](ScaleneTriangle.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.Triangle;
+import org.openapitools.client.model.EquilateralTriangle;
+import org.openapitools.client.model.IsoscelesTriangle;
+import org.openapitools.client.model.ScaleneTriangle;
+
+public class Example {
+    public static void main(String[] args) {
+        Triangle exampleTriangle = new Triangle();
+
+        // create a new EquilateralTriangle
+        EquilateralTriangle exampleEquilateralTriangle = new EquilateralTriangle();
+        // set Triangle to EquilateralTriangle
+        exampleTriangle.setActualInstance(exampleEquilateralTriangle);
+        // to get back the EquilateralTriangle set earlier
+        EquilateralTriangle testEquilateralTriangle = (EquilateralTriangle) exampleTriangle.getActualInstance();
+
+        // create a new IsoscelesTriangle
+        IsoscelesTriangle exampleIsoscelesTriangle = new IsoscelesTriangle();
+        // set Triangle to IsoscelesTriangle
+        exampleTriangle.setActualInstance(exampleIsoscelesTriangle);
+        // to get back the IsoscelesTriangle set earlier
+        IsoscelesTriangle testIsoscelesTriangle = (IsoscelesTriangle) exampleTriangle.getActualInstance();
+
+        // create a new ScaleneTriangle
+        ScaleneTriangle exampleScaleneTriangle = new ScaleneTriangle();
+        // set Triangle to ScaleneTriangle
+        exampleTriangle.setActualInstance(exampleScaleneTriangle);
+        // to get back the ScaleneTriangle set earlier
+        ScaleneTriangle testScaleneTriangle = (ScaleneTriangle) exampleTriangle.getActualInstance();
+    }
+}
+```
+
+

samples/client/petstore/java/native-async/docs/TriangleInterface.md

@@ -0,0 +1,13 @@
+
+
+# TriangleInterface
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**triangleType** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/User.md

@@ -15,6 +15,10 @@
 |**password** | **String** |  |  [optional] |
 |**phone** | **String** |  |  [optional] |
 |**userStatus** | **Integer** | User Status |  [optional] |
+|**objectWithNoDeclaredProps** | **Object** | test code generation for objects Value must be a map of strings to values. It cannot be the 'null' value. |  [optional] |
+|**objectWithNoDeclaredPropsNullable** | **Object** | test code generation for nullable objects. Value must be a map of strings to values or the 'null' value. |  [optional] |
+|**anyTypeProp** | **Object** | test code generation for any type Here the 'type' attribute is not specified, which means the value can be anything, including the null value, string, number, boolean, array or object. See https://github.com/OAI/OpenAPI-Specification/issues/1389 |  [optional] |
+|**anyTypePropNullable** | **Object** | test code generation for any type Here the 'type' attribute is not specified, which means the value can be anything, including the null value, string, number, boolean, array or object. The 'nullable' attribute does not change the allowed values. |  [optional] |
 
 
 

samples/client/petstore/java/native-async/docs/Whale.md

@@ -0,0 +1,15 @@
+
+
+# Whale
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**hasBaleen** | **Boolean** |  |  [optional] |
+|**hasTeeth** | **Boolean** |  |  [optional] |
+|**className** | **String** |  |  |
+
+
+

samples/client/petstore/java/native-async/docs/Zebra.md

@@ -0,0 +1,24 @@
+
+
+# Zebra
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**type** | [**TypeEnum**](#TypeEnum) |  |  [optional] |
+|**className** | **String** |  |  |
+
+
+
+## Enum: TypeEnum
+
+| Name | Value |
+|---- | -----|
+| PLAINS | "plains" |
+| MOUNTAIN | "mountain" |
+| GREVYS | "grevys" |
+
+
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -19,15 +19,13 @@ import org.openapitools.client.Pair;
 
 import java.math.BigDecimal;
 import org.openapitools.client.model.Client;
-import org.openapitools.client.model.EnumClass;
 import java.io.File;
 import org.openapitools.client.model.FileSchemaTestClass;
 import org.openapitools.client.model.HealthCheckResult;
 import java.time.LocalDate;
 import java.time.OffsetDateTime;
 import org.openapitools.client.model.OuterComposite;
-import org.openapitools.client.model.OuterObjectWithEnumProperty;
+import org.openapitools.client.model.OuterEnum;
-import org.openapitools.client.model.Pet;
 import org.openapitools.client.model.User;
 
 import com.fasterxml.jackson.core.type.TypeReference;
@@ -172,111 +170,6 @@ public class FakeApi {
     }
     return localVarRequestBuilder;
   }
-  /**
-   * test http signature authentication
-   * 
-   * @param pet Pet object that needs to be added to the store (required)
-   * @param query1 query parameter (optional)
-   * @param header1 header parameter (optional)
-   * @return CompletableFuture<Void>
-   * @throws ApiException if fails to make API call
-   */
-  public CompletableFuture<Void> fakeHttpSignatureTest(Pet pet, String query1, String header1) throws ApiException {
-    try {
-      HttpRequest.Builder localVarRequestBuilder = fakeHttpSignatureTestRequestBuilder(pet, query1, header1);
-      return memberVarHttpClient.sendAsync(
-          localVarRequestBuilder.build(),
-          HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
-            if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("fakeHttpSignatureTest", localVarResponse));
-            }
-            return CompletableFuture.completedFuture(null);
-      });
-    }
-    catch (ApiException e) {
-      return CompletableFuture.failedFuture(e);
-    }
-  }
-
-  /**
-   * test http signature authentication
-   * 
-   * @param pet Pet object that needs to be added to the store (required)
-   * @param query1 query parameter (optional)
-   * @param header1 header parameter (optional)
-   * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
-   * @throws ApiException if fails to make API call
-   */
-  public CompletableFuture<ApiResponse<Void>> fakeHttpSignatureTestWithHttpInfo(Pet pet, String query1, String header1) throws ApiException {
-    try {
-      HttpRequest.Builder localVarRequestBuilder = fakeHttpSignatureTestRequestBuilder(pet, query1, header1);
-      return memberVarHttpClient.sendAsync(
-          localVarRequestBuilder.build(),
-          HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
-            if (memberVarAsyncResponseInterceptor != null) {
-              memberVarAsyncResponseInterceptor.accept(localVarResponse);
-            }
-            if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("fakeHttpSignatureTest", localVarResponse));
-            }
-            return CompletableFuture.completedFuture(
-                new ApiResponse<Void>(localVarResponse.statusCode(), localVarResponse.headers().map(), null)
-            );
-        }
-      );
-    }
-    catch (ApiException e) {
-      return CompletableFuture.failedFuture(e);
-    }
-  }
-
-  private HttpRequest.Builder fakeHttpSignatureTestRequestBuilder(Pet pet, String query1, String header1) throws ApiException {
-    // verify the required parameter 'pet' is set
-    if (pet == null) {
-      throw new ApiException(400, "Missing the required parameter 'pet' when calling fakeHttpSignatureTest");
-    }
-
-    HttpRequest.Builder localVarRequestBuilder = HttpRequest.newBuilder();
-
-    String localVarPath = "/fake/http-signature-test";
-
-    List<Pair> localVarQueryParams = new ArrayList<>();
-    StringJoiner localVarQueryStringJoiner = new StringJoiner("&");
-    String localVarQueryParameterBaseName;
-    localVarQueryParameterBaseName = "query_1";
-    localVarQueryParams.addAll(ApiClient.parameterToPairs("query_1", query1));
-
-    if (!localVarQueryParams.isEmpty() || localVarQueryStringJoiner.length() != 0) {
-      StringJoiner queryJoiner = new StringJoiner("&");
-      localVarQueryParams.forEach(p -> queryJoiner.add(p.getName() + '=' + p.getValue()));
-      if (localVarQueryStringJoiner.length() != 0) {
-        queryJoiner.add(localVarQueryStringJoiner.toString());
-      }
-      localVarRequestBuilder.uri(URI.create(memberVarBaseUri + localVarPath + '?' + queryJoiner.toString()));
-    } else {
-      localVarRequestBuilder.uri(URI.create(memberVarBaseUri + localVarPath));
-    }
-
-    if (header1 != null) {
-      localVarRequestBuilder.header("header_1", header1.toString());
-    }
-    localVarRequestBuilder.header("Content-Type", "application/json");
-    localVarRequestBuilder.header("Accept", "application/json");
-
-    try {
-      byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes(pet);
-      localVarRequestBuilder.method("GET", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
-    } catch (IOException e) {
-      throw new ApiException(e);
-    }
-    if (memberVarReadTimeout != null) {
-      localVarRequestBuilder.timeout(memberVarReadTimeout);
-    }
-    if (memberVarInterceptor != null) {
-      memberVarInterceptor.accept(localVarRequestBuilder);
-    }
-    return localVarRequestBuilder;
-  }
   /**
    * 
    * Test serialization of outer boolean types
@@ -649,25 +542,24 @@ public class FakeApi {
     return localVarRequestBuilder;
   }
   /**
+   * Array of Enums
    * 
-   * Test serialization of enum (int) properties with examples
+   * @return CompletableFuture&lt;List&lt;OuterEnum&gt;&gt;
-   * @param outerObjectWithEnumProperty Input enum (int) as post body (required)
-   * @return CompletableFuture&lt;OuterObjectWithEnumProperty&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<OuterObjectWithEnumProperty> fakePropertyEnumIntegerSerialize(OuterObjectWithEnumProperty outerObjectWithEnumProperty) throws ApiException {
+  public CompletableFuture<List<OuterEnum>> getArrayOfEnums() throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = fakePropertyEnumIntegerSerializeRequestBuilder(outerObjectWithEnumProperty);
+      HttpRequest.Builder localVarRequestBuilder = getArrayOfEnumsRequestBuilder();
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
             if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("fakePropertyEnumIntegerSerialize", localVarResponse));
+              return CompletableFuture.failedFuture(getApiException("getArrayOfEnums", localVarResponse));
             }
             try {
               String responseBody = localVarResponse.body();
               return CompletableFuture.completedFuture(
-                  responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<OuterObjectWithEnumProperty>() {})
+                  responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {})
               );
             } catch (IOException e) {
               return CompletableFuture.failedFuture(new ApiException(e));
@@ -680,15 +572,14 @@ public class FakeApi {
   }
 
   /**
+   * Array of Enums
    * 
-   * Test serialization of enum (int) properties with examples
+   * @return CompletableFuture&lt;ApiResponse&lt;List&lt;OuterEnum&gt;&gt;&gt;
-   * @param outerObjectWithEnumProperty Input enum (int) as post body (required)
-   * @return CompletableFuture&lt;ApiResponse&lt;OuterObjectWithEnumProperty&gt;&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<ApiResponse<OuterObjectWithEnumProperty>> fakePropertyEnumIntegerSerializeWithHttpInfo(OuterObjectWithEnumProperty outerObjectWithEnumProperty) throws ApiException {
+  public CompletableFuture<ApiResponse<List<OuterEnum>>> getArrayOfEnumsWithHttpInfo() throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = fakePropertyEnumIntegerSerializeRequestBuilder(outerObjectWithEnumProperty);
+      HttpRequest.Builder localVarRequestBuilder = getArrayOfEnumsRequestBuilder();
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
@@ -696,15 +587,15 @@ public class FakeApi {
               memberVarAsyncResponseInterceptor.accept(localVarResponse);
             }
             if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("fakePropertyEnumIntegerSerialize", localVarResponse));
+              return CompletableFuture.failedFuture(getApiException("getArrayOfEnums", localVarResponse));
             }
             try {
               String responseBody = localVarResponse.body();
               return CompletableFuture.completedFuture(
-                  new ApiResponse<OuterObjectWithEnumProperty>(
+                  new ApiResponse<List<OuterEnum>>(
                       localVarResponse.statusCode(),
                       localVarResponse.headers().map(),
-                      responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<OuterObjectWithEnumProperty>() {}))
+                      responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {}))
               );
             } catch (IOException e) {
               return CompletableFuture.failedFuture(new ApiException(e));
@@ -717,110 +608,17 @@ public class FakeApi {
     }
   }
 
-  private HttpRequest.Builder fakePropertyEnumIntegerSerializeRequestBuilder(OuterObjectWithEnumProperty outerObjectWithEnumProperty) throws ApiException {
+  private HttpRequest.Builder getArrayOfEnumsRequestBuilder() throws ApiException {
-    // verify the required parameter 'outerObjectWithEnumProperty' is set
-    if (outerObjectWithEnumProperty == null) {
-      throw new ApiException(400, "Missing the required parameter 'outerObjectWithEnumProperty' when calling fakePropertyEnumIntegerSerialize");
-    }
 
     HttpRequest.Builder localVarRequestBuilder = HttpRequest.newBuilder();
 
-    String localVarPath = "/fake/property/enum-int";
+    String localVarPath = "/fake/array-of-enums";
 
     localVarRequestBuilder.uri(URI.create(memberVarBaseUri + localVarPath));
 
-    localVarRequestBuilder.header("Content-Type", "application/json");
-    localVarRequestBuilder.header("Accept", "*/*");
-
-    try {
-      byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes(outerObjectWithEnumProperty);
-      localVarRequestBuilder.method("POST", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
-    } catch (IOException e) {
-      throw new ApiException(e);
-    }
-    if (memberVarReadTimeout != null) {
-      localVarRequestBuilder.timeout(memberVarReadTimeout);
-    }
-    if (memberVarInterceptor != null) {
-      memberVarInterceptor.accept(localVarRequestBuilder);
-    }
-    return localVarRequestBuilder;
-  }
-  /**
-   * 
-   * For this test, the body has to be a binary file.
-   * @param body image to upload (required)
-   * @return CompletableFuture&lt;Void&gt;
-   * @throws ApiException if fails to make API call
-   */
-  public CompletableFuture<Void> testBodyWithBinary(File body) throws ApiException {
-    try {
-      HttpRequest.Builder localVarRequestBuilder = testBodyWithBinaryRequestBuilder(body);
-      return memberVarHttpClient.sendAsync(
-          localVarRequestBuilder.build(),
-          HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
-            if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("testBodyWithBinary", localVarResponse));
-            }
-            return CompletableFuture.completedFuture(null);
-      });
-    }
-    catch (ApiException e) {
-      return CompletableFuture.failedFuture(e);
-    }
-  }
-
-  /**
-   * 
-   * For this test, the body has to be a binary file.
-   * @param body image to upload (required)
-   * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
-   * @throws ApiException if fails to make API call
-   */
-  public CompletableFuture<ApiResponse<Void>> testBodyWithBinaryWithHttpInfo(File body) throws ApiException {
-    try {
-      HttpRequest.Builder localVarRequestBuilder = testBodyWithBinaryRequestBuilder(body);
-      return memberVarHttpClient.sendAsync(
-          localVarRequestBuilder.build(),
-          HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
-            if (memberVarAsyncResponseInterceptor != null) {
-              memberVarAsyncResponseInterceptor.accept(localVarResponse);
-            }
-            if (localVarResponse.statusCode()/ 100 != 2) {
-              return CompletableFuture.failedFuture(getApiException("testBodyWithBinary", localVarResponse));
-            }
-            return CompletableFuture.completedFuture(
-                new ApiResponse<Void>(localVarResponse.statusCode(), localVarResponse.headers().map(), null)
-            );
-        }
-      );
-    }
-    catch (ApiException e) {
-      return CompletableFuture.failedFuture(e);
-    }
-  }
-
-  private HttpRequest.Builder testBodyWithBinaryRequestBuilder(File body) throws ApiException {
-    // verify the required parameter 'body' is set
-    if (body == null) {
-      throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithBinary");
-    }
-
-    HttpRequest.Builder localVarRequestBuilder = HttpRequest.newBuilder();
-
-    String localVarPath = "/fake/body-with-binary";
-
-    localVarRequestBuilder.uri(URI.create(memberVarBaseUri + localVarPath));
-
-    localVarRequestBuilder.header("Content-Type", "image/png");
     localVarRequestBuilder.header("Accept", "application/json");
 
-    try {
+    localVarRequestBuilder.method("GET", HttpRequest.BodyPublishers.noBody());
-      byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes(body);
-      localVarRequestBuilder.method("PUT", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
-    } catch (IOException e) {
-      throw new ApiException(e);
-    }
     if (memberVarReadTimeout != null) {
       localVarRequestBuilder.timeout(memberVarReadTimeout);
     }
@@ -831,7 +629,7 @@ public class FakeApi {
   }
   /**
    * 
-   * For this test, the body for this request must reference a schema named &#x60;File&#x60;.
+   * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
    * @param fileSchemaTestClass  (required)
    * @return CompletableFuture&lt;Void&gt;
    * @throws ApiException if fails to make API call
@@ -855,7 +653,7 @@ public class FakeApi {
 
   /**
    * 
-   * For this test, the body for this request must reference a schema named &#x60;File&#x60;.
+   * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
    * @param fileSchemaTestClass  (required)
    * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
    * @throws ApiException if fails to make API call
@@ -1128,7 +926,7 @@ public class FakeApi {
    * @param string None (optional)
    * @param binary None (optional)
    * @param date None (optional)
-   * @param dateTime None (optional)
+   * @param dateTime None (optional, default to 2010-02-01T10:20:10.111110+01:00)
    * @param password None (optional)
    * @param paramCallback None (optional)
    * @return CompletableFuture&lt;Void&gt;
@@ -1165,7 +963,7 @@ public class FakeApi {
    * @param string None (optional)
    * @param binary None (optional)
    * @param date None (optional)
-   * @param dateTime None (optional)
+   * @param dateTime None (optional, default to 2010-02-01T10:20:10.111110+01:00)
    * @param password None (optional)
    * @param paramCallback None (optional)
    * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
@@ -1238,15 +1036,14 @@ public class FakeApi {
    * @param enumQueryString Query parameter enum test (string) (optional, default to -efg)
    * @param enumQueryInteger Query parameter enum test (double) (optional)
    * @param enumQueryDouble Query parameter enum test (double) (optional)
-   * @param enumQueryModelArray  (optional
    * @param enumFormStringArray Form parameter enum test (string array) (optional
    * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
    * @return CompletableFuture&lt;Void&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<Void> testEnumParameters(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<EnumClass> enumQueryModelArray, List<String> enumFormStringArray, String enumFormString) throws ApiException {
+  public CompletableFuture<Void> testEnumParameters(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = testEnumParametersRequestBuilder(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString);
+      HttpRequest.Builder localVarRequestBuilder = testEnumParametersRequestBuilder(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString);
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
@@ -1270,15 +1067,14 @@ public class FakeApi {
    * @param enumQueryString Query parameter enum test (string) (optional, default to -efg)
    * @param enumQueryInteger Query parameter enum test (double) (optional)
    * @param enumQueryDouble Query parameter enum test (double) (optional)
-   * @param enumQueryModelArray  (optional
    * @param enumFormStringArray Form parameter enum test (string array) (optional
    * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
    * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<ApiResponse<Void>> testEnumParametersWithHttpInfo(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<EnumClass> enumQueryModelArray, List<String> enumFormStringArray, String enumFormString) throws ApiException {
+  public CompletableFuture<ApiResponse<Void>> testEnumParametersWithHttpInfo(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = testEnumParametersRequestBuilder(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString);
+      HttpRequest.Builder localVarRequestBuilder = testEnumParametersRequestBuilder(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString);
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
@@ -1299,7 +1095,7 @@ public class FakeApi {
     }
   }
 
-  private HttpRequest.Builder testEnumParametersRequestBuilder(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<EnumClass> enumQueryModelArray, List<String> enumFormStringArray, String enumFormString) throws ApiException {
+  private HttpRequest.Builder testEnumParametersRequestBuilder(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
 
     HttpRequest.Builder localVarRequestBuilder = HttpRequest.newBuilder();
 
@@ -1316,8 +1112,6 @@ public class FakeApi {
     localVarQueryParams.addAll(ApiClient.parameterToPairs("enum_query_integer", enumQueryInteger));
     localVarQueryParameterBaseName = "enum_query_double";
     localVarQueryParams.addAll(ApiClient.parameterToPairs("enum_query_double", enumQueryDouble));
-    localVarQueryParameterBaseName = "enum_query_model_array";
-    localVarQueryParams.addAll(ApiClient.parameterToPairs("multi", "enum_query_model_array", enumQueryModelArray));
 
     if (!localVarQueryParams.isEmpty() || localVarQueryStringJoiner.length() != 0) {
       StringJoiner queryJoiner = new StringJoiner("&");
@@ -1754,14 +1548,12 @@ public class FakeApi {
    * @param http  (required)
    * @param url  (required)
    * @param context  (required)
-   * @param allowEmpty  (required)
-   * @param language  (optional
    * @return CompletableFuture&lt;Void&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<Void> testQueryParameterCollectionFormat(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context, String allowEmpty, Map<String, String> language) throws ApiException {
+  public CompletableFuture<Void> testQueryParameterCollectionFormat(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = testQueryParameterCollectionFormatRequestBuilder(pipe, ioutil, http, url, context, allowEmpty, language);
+      HttpRequest.Builder localVarRequestBuilder = testQueryParameterCollectionFormatRequestBuilder(pipe, ioutil, http, url, context);
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
@@ -1784,14 +1576,12 @@ public class FakeApi {
    * @param http  (required)
    * @param url  (required)
    * @param context  (required)
-   * @param allowEmpty  (required)
-   * @param language  (optional
    * @return CompletableFuture&lt;ApiResponse&lt;Void&gt;&gt;
    * @throws ApiException if fails to make API call
    */
-  public CompletableFuture<ApiResponse<Void>> testQueryParameterCollectionFormatWithHttpInfo(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context, String allowEmpty, Map<String, String> language) throws ApiException {
+  public CompletableFuture<ApiResponse<Void>> testQueryParameterCollectionFormatWithHttpInfo(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
     try {
-      HttpRequest.Builder localVarRequestBuilder = testQueryParameterCollectionFormatRequestBuilder(pipe, ioutil, http, url, context, allowEmpty, language);
+      HttpRequest.Builder localVarRequestBuilder = testQueryParameterCollectionFormatRequestBuilder(pipe, ioutil, http, url, context);
       return memberVarHttpClient.sendAsync(
           localVarRequestBuilder.build(),
           HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> {
@@ -1812,7 +1602,7 @@ public class FakeApi {
     }
   }
 
-  private HttpRequest.Builder testQueryParameterCollectionFormatRequestBuilder(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context, String allowEmpty, Map<String, String> language) throws ApiException {
+  private HttpRequest.Builder testQueryParameterCollectionFormatRequestBuilder(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
     // verify the required parameter 'pipe' is set
     if (pipe == null) {
       throw new ApiException(400, "Missing the required parameter 'pipe' when calling testQueryParameterCollectionFormat");
@@ -1833,10 +1623,6 @@ public class FakeApi {
     if (context == null) {
       throw new ApiException(400, "Missing the required parameter 'context' when calling testQueryParameterCollectionFormat");
     }
-    // verify the required parameter 'allowEmpty' is set
-    if (allowEmpty == null) {
-      throw new ApiException(400, "Missing the required parameter 'allowEmpty' when calling testQueryParameterCollectionFormat");
-    }
 
     HttpRequest.Builder localVarRequestBuilder = HttpRequest.newBuilder();
 
@@ -1846,7 +1632,7 @@ public class FakeApi {
     StringJoiner localVarQueryStringJoiner = new StringJoiner("&");
     String localVarQueryParameterBaseName;
     localVarQueryParameterBaseName = "pipe";
-    localVarQueryParams.addAll(ApiClient.parameterToPairs("pipes", "pipe", pipe));
+    localVarQueryParams.addAll(ApiClient.parameterToPairs("multi", "pipe", pipe));
     localVarQueryParameterBaseName = "ioutil";
     localVarQueryParams.addAll(ApiClient.parameterToPairs("csv", "ioutil", ioutil));
     localVarQueryParameterBaseName = "http";
@@ -1855,10 +1641,6 @@ public class FakeApi {
     localVarQueryParams.addAll(ApiClient.parameterToPairs("csv", "url", url));
     localVarQueryParameterBaseName = "context";
     localVarQueryParams.addAll(ApiClient.parameterToPairs("multi", "context", context));
-    localVarQueryParameterBaseName = "language";
-    localVarQueryParams.addAll(ApiClient.parameterToPairs("language", language));
-    localVarQueryParameterBaseName = "allowEmpty";
-    localVarQueryParams.addAll(ApiClient.parameterToPairs("allowEmpty", allowEmpty));
 
     if (!localVarQueryParams.isEmpty() || localVarQueryStringJoiner.length() != 0) {
       StringJoiner queryJoiner = new StringJoiner("&");

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/PetApi.java

@@ -20,7 +20,6 @@ import org.openapitools.client.Pair;
 import java.io.File;
 import org.openapitools.client.model.ModelApiResponse;
 import org.openapitools.client.model.Pet;
-import java.util.Set;
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -355,12 +354,12 @@ public class PetApi {
    * Finds Pets by tags
    * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
    * @param tags Tags to filter by (required)
-   * @return CompletableFuture<Set<Pet>>
+   * @return CompletableFuture<List<Pet>>
    * @throws ApiException if fails to make API call
    * @deprecated
    */
   @Deprecated
-  public CompletableFuture<Set<Pet>> findPetsByTags(Set<String> tags) throws ApiException {
+  public CompletableFuture<List<Pet>> findPetsByTags(List<String> tags) throws ApiException {
     try {
       HttpRequest.Builder localVarRequestBuilder = findPetsByTagsRequestBuilder(tags);
       return memberVarHttpClient.sendAsync(
@@ -372,7 +371,7 @@ public class PetApi {
             try {
               String responseBody = localVarResponse.body();
               return CompletableFuture.completedFuture(
-                  responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<Set<Pet>>() {})
+                  responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {})
               );
             } catch (IOException e) {
               return CompletableFuture.failedFuture(new ApiException(e));
@@ -388,12 +387,12 @@ public class PetApi {
    * Finds Pets by tags
    * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
    * @param tags Tags to filter by (required)
-   * @return CompletableFuture&lt;ApiResponse&lt;Set&lt;Pet&gt;&gt;&gt;
+   * @return CompletableFuture&lt;ApiResponse&lt;List&lt;Pet&gt;&gt;&gt;
    * @throws ApiException if fails to make API call
    * @deprecated
    */
   @Deprecated
-  public CompletableFuture<ApiResponse<Set<Pet>>> findPetsByTagsWithHttpInfo(Set<String> tags) throws ApiException {
+  public CompletableFuture<ApiResponse<List<Pet>>> findPetsByTagsWithHttpInfo(List<String> tags) throws ApiException {
     try {
       HttpRequest.Builder localVarRequestBuilder = findPetsByTagsRequestBuilder(tags);
       return memberVarHttpClient.sendAsync(
@@ -408,10 +407,10 @@ public class PetApi {
             try {
               String responseBody = localVarResponse.body();
               return CompletableFuture.completedFuture(
-                  new ApiResponse<Set<Pet>>(
+                  new ApiResponse<List<Pet>>(
                       localVarResponse.statusCode(),
                       localVarResponse.headers().map(),
-                      responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<Set<Pet>>() {}))
+                      responseBody == null || responseBody.isBlank() ? null : memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {}))
               );
             } catch (IOException e) {
               return CompletableFuture.failedFuture(new ApiException(e));
@@ -424,7 +423,7 @@ public class PetApi {
     }
   }
 
-  private HttpRequest.Builder findPetsByTagsRequestBuilder(Set<String> tags) throws ApiException {
+  private HttpRequest.Builder findPetsByTagsRequestBuilder(List<String> tags) throws ApiException {
     // verify the required parameter 'tags' is set
     if (tags == null) {
       throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java

@@ -27,6 +27,10 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import java.util.HashMap;
 import java.util.Map;
+import org.openapitools.jackson.nullable.JsonNullable;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
@@ -35,7 +39,13 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
  */
 @JsonPropertyOrder({
   AdditionalPropertiesClass.JSON_PROPERTY_MAP_PROPERTY,
-  AdditionalPropertiesClass.JSON_PROPERTY_MAP_OF_MAP_PROPERTY
+  AdditionalPropertiesClass.JSON_PROPERTY_MAP_OF_MAP_PROPERTY,
+  AdditionalPropertiesClass.JSON_PROPERTY_ANYTYPE1,
+  AdditionalPropertiesClass.JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1,
+  AdditionalPropertiesClass.JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2,
+  AdditionalPropertiesClass.JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3,
+  AdditionalPropertiesClass.JSON_PROPERTY_EMPTY_MAP,
+  AdditionalPropertiesClass.JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_STRING
 })
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class AdditionalPropertiesClass {
@@ -45,6 +55,24 @@ public class AdditionalPropertiesClass {
   public static final String JSON_PROPERTY_MAP_OF_MAP_PROPERTY = "map_of_map_property";
   private Map<String, Map<String, String>> mapOfMapProperty = null;
 
+  public static final String JSON_PROPERTY_ANYTYPE1 = "anytype_1";
+  private JsonNullable<Object> anytype1 = JsonNullable.<Object>of(null);
+
+  public static final String JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1 = "map_with_undeclared_properties_anytype_1";
+  private Object mapWithUndeclaredPropertiesAnytype1;
+
+  public static final String JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2 = "map_with_undeclared_properties_anytype_2";
+  private Object mapWithUndeclaredPropertiesAnytype2;
+
+  public static final String JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3 = "map_with_undeclared_properties_anytype_3";
+  private Map<String, Object> mapWithUndeclaredPropertiesAnytype3 = null;
+
+  public static final String JSON_PROPERTY_EMPTY_MAP = "empty_map";
+  private Object emptyMap;
+
+  public static final String JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_STRING = "map_with_undeclared_properties_string";
+  private Map<String, String> mapWithUndeclaredPropertiesString = null;
+
   public AdditionalPropertiesClass() { 
   }
 
@@ -114,6 +142,180 @@ public class AdditionalPropertiesClass {
   }
 
 
+  public AdditionalPropertiesClass anytype1(Object anytype1) {
+    this.anytype1 = JsonNullable.<Object>of(anytype1);
+    return this;
+  }
+
+   /**
+   * Get anytype1
+   * @return anytype1
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public Object getAnytype1() {
+        return anytype1.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_ANYTYPE1)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<Object> getAnytype1_JsonNullable() {
+    return anytype1;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_ANYTYPE1)
+  public void setAnytype1_JsonNullable(JsonNullable<Object> anytype1) {
+    this.anytype1 = anytype1;
+  }
+
+  public void setAnytype1(Object anytype1) {
+    this.anytype1 = JsonNullable.<Object>of(anytype1);
+  }
+
+
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype1(Object mapWithUndeclaredPropertiesAnytype1) {
+    this.mapWithUndeclaredPropertiesAnytype1 = mapWithUndeclaredPropertiesAnytype1;
+    return this;
+  }
+
+   /**
+   * Get mapWithUndeclaredPropertiesAnytype1
+   * @return mapWithUndeclaredPropertiesAnytype1
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Object getMapWithUndeclaredPropertiesAnytype1() {
+    return mapWithUndeclaredPropertiesAnytype1;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMapWithUndeclaredPropertiesAnytype1(Object mapWithUndeclaredPropertiesAnytype1) {
+    this.mapWithUndeclaredPropertiesAnytype1 = mapWithUndeclaredPropertiesAnytype1;
+  }
+
+
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype2(Object mapWithUndeclaredPropertiesAnytype2) {
+    this.mapWithUndeclaredPropertiesAnytype2 = mapWithUndeclaredPropertiesAnytype2;
+    return this;
+  }
+
+   /**
+   * Get mapWithUndeclaredPropertiesAnytype2
+   * @return mapWithUndeclaredPropertiesAnytype2
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Object getMapWithUndeclaredPropertiesAnytype2() {
+    return mapWithUndeclaredPropertiesAnytype2;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMapWithUndeclaredPropertiesAnytype2(Object mapWithUndeclaredPropertiesAnytype2) {
+    this.mapWithUndeclaredPropertiesAnytype2 = mapWithUndeclaredPropertiesAnytype2;
+  }
+
+
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype3(Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
+    this.mapWithUndeclaredPropertiesAnytype3 = mapWithUndeclaredPropertiesAnytype3;
+    return this;
+  }
+
+  public AdditionalPropertiesClass putMapWithUndeclaredPropertiesAnytype3Item(String key, Object mapWithUndeclaredPropertiesAnytype3Item) {
+    if (this.mapWithUndeclaredPropertiesAnytype3 == null) {
+      this.mapWithUndeclaredPropertiesAnytype3 = new HashMap<>();
+    }
+    this.mapWithUndeclaredPropertiesAnytype3.put(key, mapWithUndeclaredPropertiesAnytype3Item);
+    return this;
+  }
+
+   /**
+   * Get mapWithUndeclaredPropertiesAnytype3
+   * @return mapWithUndeclaredPropertiesAnytype3
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3)
+  @JsonInclude(content = JsonInclude.Include.ALWAYS, value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Map<String, Object> getMapWithUndeclaredPropertiesAnytype3() {
+    return mapWithUndeclaredPropertiesAnytype3;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3)
+  @JsonInclude(content = JsonInclude.Include.ALWAYS, value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMapWithUndeclaredPropertiesAnytype3(Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
+    this.mapWithUndeclaredPropertiesAnytype3 = mapWithUndeclaredPropertiesAnytype3;
+  }
+
+
+  public AdditionalPropertiesClass emptyMap(Object emptyMap) {
+    this.emptyMap = emptyMap;
+    return this;
+  }
+
+   /**
+   * an object with no declared properties and no undeclared properties, hence it&#39;s an empty map.
+   * @return emptyMap
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_EMPTY_MAP)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Object getEmptyMap() {
+    return emptyMap;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_EMPTY_MAP)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setEmptyMap(Object emptyMap) {
+    this.emptyMap = emptyMap;
+  }
+
+
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesString(Map<String, String> mapWithUndeclaredPropertiesString) {
+    this.mapWithUndeclaredPropertiesString = mapWithUndeclaredPropertiesString;
+    return this;
+  }
+
+  public AdditionalPropertiesClass putMapWithUndeclaredPropertiesStringItem(String key, String mapWithUndeclaredPropertiesStringItem) {
+    if (this.mapWithUndeclaredPropertiesString == null) {
+      this.mapWithUndeclaredPropertiesString = new HashMap<>();
+    }
+    this.mapWithUndeclaredPropertiesString.put(key, mapWithUndeclaredPropertiesStringItem);
+    return this;
+  }
+
+   /**
+   * Get mapWithUndeclaredPropertiesString
+   * @return mapWithUndeclaredPropertiesString
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_STRING)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Map<String, String> getMapWithUndeclaredPropertiesString() {
+    return mapWithUndeclaredPropertiesString;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MAP_WITH_UNDECLARED_PROPERTIES_STRING)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMapWithUndeclaredPropertiesString(Map<String, String> mapWithUndeclaredPropertiesString) {
+    this.mapWithUndeclaredPropertiesString = mapWithUndeclaredPropertiesString;
+  }
+
+
   /**
    * Return true if this AdditionalPropertiesClass object is equal to o.
    */
@@ -127,12 +329,29 @@ public class AdditionalPropertiesClass {
     }
     AdditionalPropertiesClass additionalPropertiesClass = (AdditionalPropertiesClass) o;
     return Objects.equals(this.mapProperty, additionalPropertiesClass.mapProperty) &&
-        Objects.equals(this.mapOfMapProperty, additionalPropertiesClass.mapOfMapProperty);
+        Objects.equals(this.mapOfMapProperty, additionalPropertiesClass.mapOfMapProperty) &&
+        equalsNullable(this.anytype1, additionalPropertiesClass.anytype1) &&
+        Objects.equals(this.mapWithUndeclaredPropertiesAnytype1, additionalPropertiesClass.mapWithUndeclaredPropertiesAnytype1) &&
+        Objects.equals(this.mapWithUndeclaredPropertiesAnytype2, additionalPropertiesClass.mapWithUndeclaredPropertiesAnytype2) &&
+        Objects.equals(this.mapWithUndeclaredPropertiesAnytype3, additionalPropertiesClass.mapWithUndeclaredPropertiesAnytype3) &&
+        Objects.equals(this.emptyMap, additionalPropertiesClass.emptyMap) &&
+        Objects.equals(this.mapWithUndeclaredPropertiesString, additionalPropertiesClass.mapWithUndeclaredPropertiesString);
+  }
+
+  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(mapProperty, mapOfMapProperty);
+    return Objects.hash(mapProperty, mapOfMapProperty, hashCodeNullable(anytype1), mapWithUndeclaredPropertiesAnytype1, mapWithUndeclaredPropertiesAnytype2, mapWithUndeclaredPropertiesAnytype3, emptyMap, mapWithUndeclaredPropertiesString);
+  }
+
+  private static <T> int hashCodeNullable(JsonNullable<T> a) {
+    if (a == null) {
+      return 1;
+    }
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
@@ -141,6 +360,12 @@ public class AdditionalPropertiesClass {
     sb.append("class AdditionalPropertiesClass {\n");
     sb.append("    mapProperty: ").append(toIndentedString(mapProperty)).append("\n");
     sb.append("    mapOfMapProperty: ").append(toIndentedString(mapOfMapProperty)).append("\n");
+    sb.append("    anytype1: ").append(toIndentedString(anytype1)).append("\n");
+    sb.append("    mapWithUndeclaredPropertiesAnytype1: ").append(toIndentedString(mapWithUndeclaredPropertiesAnytype1)).append("\n");
+    sb.append("    mapWithUndeclaredPropertiesAnytype2: ").append(toIndentedString(mapWithUndeclaredPropertiesAnytype2)).append("\n");
+    sb.append("    mapWithUndeclaredPropertiesAnytype3: ").append(toIndentedString(mapWithUndeclaredPropertiesAnytype3)).append("\n");
+    sb.append("    emptyMap: ").append(toIndentedString(emptyMap)).append("\n");
+    sb.append("    mapWithUndeclaredPropertiesString: ").append(toIndentedString(mapWithUndeclaredPropertiesString)).append("\n");
     sb.append("}");
     return sb.toString();
   }
@@ -206,6 +431,44 @@ public class AdditionalPropertiesClass {
       }
     }
 
+    // add `anytype_1` to the URL query string
+    if (getAnytype1() != null) {
+      joiner.add(String.format("%sanytype_1%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getAnytype1()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `map_with_undeclared_properties_anytype_1` to the URL query string
+    if (getMapWithUndeclaredPropertiesAnytype1() != null) {
+      joiner.add(String.format("%smap_with_undeclared_properties_anytype_1%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getMapWithUndeclaredPropertiesAnytype1()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `map_with_undeclared_properties_anytype_2` to the URL query string
+    if (getMapWithUndeclaredPropertiesAnytype2() != null) {
+      joiner.add(String.format("%smap_with_undeclared_properties_anytype_2%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getMapWithUndeclaredPropertiesAnytype2()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `map_with_undeclared_properties_anytype_3` to the URL query string
+    if (getMapWithUndeclaredPropertiesAnytype3() != null) {
+      for (String _key : getMapWithUndeclaredPropertiesAnytype3().keySet()) {
+        joiner.add(String.format("%smap_with_undeclared_properties_anytype_3%s%s=%s", prefix, suffix,
+            "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, _key, containerSuffix),
+            getMapWithUndeclaredPropertiesAnytype3().get(_key), URLEncoder.encode(String.valueOf(getMapWithUndeclaredPropertiesAnytype3().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      }
+    }
+
+    // add `empty_map` to the URL query string
+    if (getEmptyMap() != null) {
+      joiner.add(String.format("%sempty_map%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getEmptyMap()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `map_with_undeclared_properties_string` to the URL query string
+    if (getMapWithUndeclaredPropertiesString() != null) {
+      for (String _key : getMapWithUndeclaredPropertiesString().keySet()) {
+        joiner.add(String.format("%smap_with_undeclared_properties_string%s%s=%s", prefix, suffix,
+            "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, _key, containerSuffix),
+            getMapWithUndeclaredPropertiesString().get(_key), URLEncoder.encode(String.valueOf(getMapWithUndeclaredPropertiesString().get(_key)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      }
+    }
+
     return joiner.toString();
   }
 }

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Apple.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * Apple
+ */
+@JsonPropertyOrder({
+  Apple.JSON_PROPERTY_CULTIVAR,
+  Apple.JSON_PROPERTY_ORIGIN
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Apple {
+  public static final String JSON_PROPERTY_CULTIVAR = "cultivar";
+  private String cultivar;
+
+  public static final String JSON_PROPERTY_ORIGIN = "origin";
+  private String origin;
+
+  public Apple() { 
+  }
+
+  public Apple cultivar(String cultivar) {
+    this.cultivar = cultivar;
+    return this;
+  }
+
+   /**
+   * Get cultivar
+   * @return cultivar
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_CULTIVAR)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getCultivar() {
+    return cultivar;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CULTIVAR)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setCultivar(String cultivar) {
+    this.cultivar = cultivar;
+  }
+
+
+  public Apple origin(String origin) {
+    this.origin = origin;
+    return this;
+  }
+
+   /**
+   * Get origin
+   * @return origin
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_ORIGIN)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getOrigin() {
+    return origin;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_ORIGIN)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setOrigin(String origin) {
+    this.origin = origin;
+  }
+
+
+  /**
+   * Return true if this apple object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Apple apple = (Apple) o;
+    return Objects.equals(this.cultivar, apple.cultivar) &&
+        Objects.equals(this.origin, apple.origin);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(cultivar, origin);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class Apple {\n");
+    sb.append("    cultivar: ").append(toIndentedString(cultivar)).append("\n");
+    sb.append("    origin: ").append(toIndentedString(origin)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `cultivar` to the URL query string
+    if (getCultivar() != null) {
+      joiner.add(String.format("%scultivar%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getCultivar()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `origin` to the URL query string
+    if (getOrigin() != null) {
+      joiner.add(String.format("%sorigin%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getOrigin()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AppleReq.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * AppleReq
+ */
+@JsonPropertyOrder({
+  AppleReq.JSON_PROPERTY_CULTIVAR,
+  AppleReq.JSON_PROPERTY_MEALY
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class AppleReq {
+  public static final String JSON_PROPERTY_CULTIVAR = "cultivar";
+  private String cultivar;
+
+  public static final String JSON_PROPERTY_MEALY = "mealy";
+  private Boolean mealy;
+
+  public AppleReq() { 
+  }
+
+  public AppleReq cultivar(String cultivar) {
+    this.cultivar = cultivar;
+    return this;
+  }
+
+   /**
+   * Get cultivar
+   * @return cultivar
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_CULTIVAR)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getCultivar() {
+    return cultivar;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CULTIVAR)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setCultivar(String cultivar) {
+    this.cultivar = cultivar;
+  }
+
+
+  public AppleReq mealy(Boolean mealy) {
+    this.mealy = mealy;
+    return this;
+  }
+
+   /**
+   * Get mealy
+   * @return mealy
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MEALY)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Boolean getMealy() {
+    return mealy;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MEALY)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMealy(Boolean mealy) {
+    this.mealy = mealy;
+  }
+
+
+  /**
+   * Return true if this appleReq object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    AppleReq appleReq = (AppleReq) o;
+    return Objects.equals(this.cultivar, appleReq.cultivar) &&
+        Objects.equals(this.mealy, appleReq.mealy);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(cultivar, mealy);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class AppleReq {\n");
+    sb.append("    cultivar: ").append(toIndentedString(cultivar)).append("\n");
+    sb.append("    mealy: ").append(toIndentedString(mealy)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `cultivar` to the URL query string
+    if (getCultivar() != null) {
+      joiner.add(String.format("%scultivar%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getCultivar()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `mealy` to the URL query string
+    if (getMealy() != null) {
+      joiner.add(String.format("%smealy%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getMealy()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Banana.java

@@ -0,0 +1,151 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * Banana
+ */
+@JsonPropertyOrder({
+  Banana.JSON_PROPERTY_LENGTH_CM
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Banana {
+  public static final String JSON_PROPERTY_LENGTH_CM = "lengthCm";
+  private BigDecimal lengthCm;
+
+  public Banana() { 
+  }
+
+  public Banana lengthCm(BigDecimal lengthCm) {
+    this.lengthCm = lengthCm;
+    return this;
+  }
+
+   /**
+   * Get lengthCm
+   * @return lengthCm
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_LENGTH_CM)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public BigDecimal getLengthCm() {
+    return lengthCm;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_LENGTH_CM)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setLengthCm(BigDecimal lengthCm) {
+    this.lengthCm = lengthCm;
+  }
+
+
+  /**
+   * Return true if this banana object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Banana banana = (Banana) o;
+    return Objects.equals(this.lengthCm, banana.lengthCm);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(lengthCm);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class Banana {\n");
+    sb.append("    lengthCm: ").append(toIndentedString(lengthCm)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `lengthCm` to the URL query string
+    if (getLengthCm() != null) {
+      joiner.add(String.format("%slengthCm%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getLengthCm()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BananaReq.java

@@ -0,0 +1,187 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * BananaReq
+ */
+@JsonPropertyOrder({
+  BananaReq.JSON_PROPERTY_LENGTH_CM,
+  BananaReq.JSON_PROPERTY_SWEET
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class BananaReq {
+  public static final String JSON_PROPERTY_LENGTH_CM = "lengthCm";
+  private BigDecimal lengthCm;
+
+  public static final String JSON_PROPERTY_SWEET = "sweet";
+  private Boolean sweet;
+
+  public BananaReq() { 
+  }
+
+  public BananaReq lengthCm(BigDecimal lengthCm) {
+    this.lengthCm = lengthCm;
+    return this;
+  }
+
+   /**
+   * Get lengthCm
+   * @return lengthCm
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_LENGTH_CM)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public BigDecimal getLengthCm() {
+    return lengthCm;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_LENGTH_CM)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setLengthCm(BigDecimal lengthCm) {
+    this.lengthCm = lengthCm;
+  }
+
+
+  public BananaReq sweet(Boolean sweet) {
+    this.sweet = sweet;
+    return this;
+  }
+
+   /**
+   * Get sweet
+   * @return sweet
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_SWEET)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Boolean getSweet() {
+    return sweet;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SWEET)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setSweet(Boolean sweet) {
+    this.sweet = sweet;
+  }
+
+
+  /**
+   * Return true if this bananaReq object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    BananaReq bananaReq = (BananaReq) o;
+    return Objects.equals(this.lengthCm, bananaReq.lengthCm) &&
+        Objects.equals(this.sweet, bananaReq.sweet);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(lengthCm, sweet);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class BananaReq {\n");
+    sb.append("    lengthCm: ").append(toIndentedString(lengthCm)).append("\n");
+    sb.append("    sweet: ").append(toIndentedString(sweet)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `lengthCm` to the URL query string
+    if (getLengthCm() != null) {
+      joiner.add(String.format("%slengthCm%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getLengthCm()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `sweet` to the URL query string
+    if (getSweet() != null) {
+      joiner.add(String.format("%ssweet%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getSweet()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BasquePig.java

@@ -0,0 +1,150 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * BasquePig
+ */
+@JsonPropertyOrder({
+  BasquePig.JSON_PROPERTY_CLASS_NAME
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class BasquePig {
+  public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  private String className;
+
+  public BasquePig() { 
+  }
+
+  public BasquePig className(String className) {
+    this.className = className;
+    return this;
+  }
+
+   /**
+   * Get className
+   * @return className
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getClassName() {
+    return className;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setClassName(String className) {
+    this.className = className;
+  }
+
+
+  /**
+   * Return true if this BasquePig object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    BasquePig basquePig = (BasquePig) o;
+    return Objects.equals(this.className, basquePig.className);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(className);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class BasquePig {\n");
+    sb.append("    className: ").append(toIndentedString(className)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `className` to the URL query string
+    if (getClassName() != null) {
+      joiner.add(String.format("%sclassName%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCat.java

@@ -0,0 +1,219 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.ParentPet;
+import java.util.Set;
+import java.util.HashSet;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+import org.openapitools.client.JSON;
+/**
+ * ChildCat
+ */
+@JsonPropertyOrder({
+  ChildCat.JSON_PROPERTY_NAME,
+  ChildCat.JSON_PROPERTY_PET_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonIgnoreProperties(
+  value = "pet_type", // ignore manually set pet_type, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the pet_type to be set during deserialization
+)
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "pet_type", visible = true)
+
+public class ChildCat extends ParentPet {
+  public static final String JSON_PROPERTY_NAME = "name";
+  private String name;
+
+  public static final String JSON_PROPERTY_PET_TYPE = "pet_type";
+  private String petType = "ChildCat";
+
+  public ChildCat() { 
+  }
+
+  public ChildCat name(String name) {
+    this.name = name;
+    return this;
+  }
+
+   /**
+   * Get name
+   * @return name
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getName() {
+    return name;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setName(String name) {
+    this.name = name;
+  }
+
+
+  public static final Set<String> PET_TYPE_VALUES = new HashSet<>(Arrays.asList(
+    "ChildCat"
+  ));
+
+  public ChildCat petType(String petType) {
+    if (!PET_TYPE_VALUES.contains(petType)) {
+      throw new IllegalArgumentException(petType + " is invalid. Possible values for petType: " + String.join(", ", PET_TYPE_VALUES));
+    }
+
+    this.petType = petType;
+    return this;
+  }
+
+   /**
+   * Get petType
+   * @return petType
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getPetType() {
+    return petType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setPetType(String petType) {
+    if (!PET_TYPE_VALUES.contains(petType)) {
+      throw new IllegalArgumentException(petType + " is invalid. Possible values for petType: " + String.join(", ", PET_TYPE_VALUES));
+    }
+
+    this.petType = petType;
+  }
+
+
+  /**
+   * Return true if this ChildCat object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ChildCat childCat = (ChildCat) o;
+    return Objects.equals(this.name, childCat.name) &&
+        Objects.equals(this.petType, childCat.petType) &&
+        super.equals(o);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(name, petType, super.hashCode());
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ChildCat {\n");
+    sb.append("    ").append(toIndentedString(super.toString())).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    petType: ").append(toIndentedString(petType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `pet_type` to the URL query string
+    if (getPetType() != null) {
+      joiner.add(String.format("%spet_type%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getPetType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `name` to the URL query string
+    if (getName() != null) {
+      joiner.add(String.format("%sname%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+static {
+  // Initialize and register the discriminator mappings.
+  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  mappings.put("ChildCat", ChildCat.class);
+  JSON.registerDiscriminator(ChildCat.class, "pet_type", mappings);
+}
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCatAllOf.java

@@ -0,0 +1,200 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.Set;
+import java.util.HashSet;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * ChildCatAllOf
+ */
+@JsonPropertyOrder({
+  ChildCatAllOf.JSON_PROPERTY_NAME,
+  ChildCatAllOf.JSON_PROPERTY_PET_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ChildCatAllOf {
+  public static final String JSON_PROPERTY_NAME = "name";
+  private String name;
+
+  public static final String JSON_PROPERTY_PET_TYPE = "pet_type";
+  private String petType = "ChildCat";
+
+  public ChildCatAllOf() { 
+  }
+
+  public ChildCatAllOf name(String name) {
+    this.name = name;
+    return this;
+  }
+
+   /**
+   * Get name
+   * @return name
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getName() {
+    return name;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setName(String name) {
+    this.name = name;
+  }
+
+
+  public static final Set<String> PET_TYPE_VALUES = new HashSet<>(Arrays.asList(
+    "ChildCat"
+  ));
+
+  public ChildCatAllOf petType(String petType) {
+    if (!PET_TYPE_VALUES.contains(petType)) {
+      throw new IllegalArgumentException(petType + " is invalid. Possible values for petType: " + String.join(", ", PET_TYPE_VALUES));
+    }
+
+    this.petType = petType;
+    return this;
+  }
+
+   /**
+   * Get petType
+   * @return petType
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getPetType() {
+    return petType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setPetType(String petType) {
+    if (!PET_TYPE_VALUES.contains(petType)) {
+      throw new IllegalArgumentException(petType + " is invalid. Possible values for petType: " + String.join(", ", PET_TYPE_VALUES));
+    }
+
+    this.petType = petType;
+  }
+
+
+  /**
+   * Return true if this ChildCat_allOf object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ChildCatAllOf childCatAllOf = (ChildCatAllOf) o;
+    return Objects.equals(this.name, childCatAllOf.name) &&
+        Objects.equals(this.petType, childCatAllOf.petType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(name, petType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ChildCatAllOf {\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    petType: ").append(toIndentedString(petType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `name` to the URL query string
+    if (getName() != null) {
+      joiner.add(String.format("%sname%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `pet_type` to the URL query string
+    if (getPetType() != null) {
+      joiner.add(String.format("%spet_type%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getPetType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * ComplexQuadrilateral
+ */
+@JsonPropertyOrder({
+  ComplexQuadrilateral.JSON_PROPERTY_SHAPE_TYPE,
+  ComplexQuadrilateral.JSON_PROPERTY_QUADRILATERAL_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ComplexQuadrilateral {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public static final String JSON_PROPERTY_QUADRILATERAL_TYPE = "quadrilateralType";
+  private String quadrilateralType;
+
+  public ComplexQuadrilateral() { 
+  }
+
+  public ComplexQuadrilateral shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  public ComplexQuadrilateral quadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+    return this;
+  }
+
+   /**
+   * Get quadrilateralType
+   * @return quadrilateralType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getQuadrilateralType() {
+    return quadrilateralType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setQuadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+  }
+
+
+  /**
+   * Return true if this ComplexQuadrilateral object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ComplexQuadrilateral complexQuadrilateral = (ComplexQuadrilateral) o;
+    return Objects.equals(this.shapeType, complexQuadrilateral.shapeType) &&
+        Objects.equals(this.quadrilateralType, complexQuadrilateral.quadrilateralType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType, quadrilateralType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ComplexQuadrilateral {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("    quadrilateralType: ").append(toIndentedString(quadrilateralType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `quadrilateralType` to the URL query string
+    if (getQuadrilateralType() != null) {
+      joiner.add(String.format("%squadrilateralType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getQuadrilateralType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DanishPig.java

@@ -0,0 +1,150 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * DanishPig
+ */
+@JsonPropertyOrder({
+  DanishPig.JSON_PROPERTY_CLASS_NAME
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class DanishPig {
+  public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  private String className;
+
+  public DanishPig() { 
+  }
+
+  public DanishPig className(String className) {
+    this.className = className;
+    return this;
+  }
+
+   /**
+   * Get className
+   * @return className
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getClassName() {
+    return className;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setClassName(String className) {
+    this.className = className;
+  }
+
+
+  /**
+   * Return true if this DanishPig object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    DanishPig danishPig = (DanishPig) o;
+    return Objects.equals(this.className, danishPig.className);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(className);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class DanishPig {\n");
+    sb.append("    className: ").append(toIndentedString(className)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `className` to the URL query string
+    if (getClassName() != null) {
+      joiner.add(String.format("%sclassName%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java

@@ -0,0 +1,353 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import java.util.Map;
+import java.util.HashMap;
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.openapitools.client.model.Fruit;
+import org.openapitools.client.model.NullableShape;
+import org.openapitools.client.model.Shape;
+import org.openapitools.client.model.ShapeOrNull;
+import org.openapitools.jackson.nullable.JsonNullable;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.util.NoSuchElementException;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * Drawing
+ */
+@JsonPropertyOrder({
+  Drawing.JSON_PROPERTY_MAIN_SHAPE,
+  Drawing.JSON_PROPERTY_SHAPE_OR_NULL,
+  Drawing.JSON_PROPERTY_NULLABLE_SHAPE,
+  Drawing.JSON_PROPERTY_SHAPES
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Drawing extends HashMap<String, Fruit> {
+  public static final String JSON_PROPERTY_MAIN_SHAPE = "mainShape";
+  private Shape mainShape;
+
+  public static final String JSON_PROPERTY_SHAPE_OR_NULL = "shapeOrNull";
+  private ShapeOrNull shapeOrNull;
+
+  public static final String JSON_PROPERTY_NULLABLE_SHAPE = "nullableShape";
+  private JsonNullable<NullableShape> nullableShape = JsonNullable.<NullableShape>undefined();
+
+  public static final String JSON_PROPERTY_SHAPES = "shapes";
+  private List<Shape> shapes = null;
+
+  public Drawing() { 
+  }
+
+  public Drawing mainShape(Shape mainShape) {
+    this.mainShape = mainShape;
+    return this;
+  }
+
+   /**
+   * Get mainShape
+   * @return mainShape
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_MAIN_SHAPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Shape getMainShape() {
+    return mainShape;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_MAIN_SHAPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setMainShape(Shape mainShape) {
+    this.mainShape = mainShape;
+  }
+
+
+  public Drawing shapeOrNull(ShapeOrNull shapeOrNull) {
+    this.shapeOrNull = shapeOrNull;
+    return this;
+  }
+
+   /**
+   * Get shapeOrNull
+   * @return shapeOrNull
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_SHAPE_OR_NULL)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public ShapeOrNull getShapeOrNull() {
+    return shapeOrNull;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_OR_NULL)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setShapeOrNull(ShapeOrNull shapeOrNull) {
+    this.shapeOrNull = shapeOrNull;
+  }
+
+
+  public Drawing nullableShape(NullableShape nullableShape) {
+    this.nullableShape = JsonNullable.<NullableShape>of(nullableShape);
+    return this;
+  }
+
+   /**
+   * Get nullableShape
+   * @return nullableShape
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public NullableShape getNullableShape() {
+        return nullableShape.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_NULLABLE_SHAPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<NullableShape> getNullableShape_JsonNullable() {
+    return nullableShape;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_NULLABLE_SHAPE)
+  public void setNullableShape_JsonNullable(JsonNullable<NullableShape> nullableShape) {
+    this.nullableShape = nullableShape;
+  }
+
+  public void setNullableShape(NullableShape nullableShape) {
+    this.nullableShape = JsonNullable.<NullableShape>of(nullableShape);
+  }
+
+
+  public Drawing shapes(List<Shape> shapes) {
+    this.shapes = shapes;
+    return this;
+  }
+
+  public Drawing addShapesItem(Shape shapesItem) {
+    if (this.shapes == null) {
+      this.shapes = new ArrayList<>();
+    }
+    this.shapes.add(shapesItem);
+    return this;
+  }
+
+   /**
+   * Get shapes
+   * @return shapes
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_SHAPES)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public List<Shape> getShapes() {
+    return shapes;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPES)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setShapes(List<Shape> shapes) {
+    this.shapes = shapes;
+  }
+
+  /**
+   * A container for additional, undeclared properties.
+   * This is a holder for any undeclared properties as specified with
+   * the 'additionalProperties' keyword in the OAS document.
+   */
+  private Map<String, Fruit> additionalProperties;
+
+  /**
+   * Set the additional (undeclared) property with the specified name and value.
+   * If the property does not already exist, create it otherwise replace it.
+   * @param key the name of the property
+   * @param value the value of the property
+   * @return self reference
+   */
+  @JsonAnySetter
+  public Drawing putAdditionalProperty(String key, Fruit value) {
+    if (this.additionalProperties == null) {
+        this.additionalProperties = new HashMap<String, Fruit>();
+    }
+    this.additionalProperties.put(key, value);
+    return this;
+  }
+
+  /**
+   * Return the additional (undeclared) properties.
+   * @return the additional (undeclared) properties
+   */
+  @JsonAnyGetter
+  public Map<String, Fruit> getAdditionalProperties() {
+    return additionalProperties;
+  }
+
+  /**
+   * Return the additional (undeclared) property with the specified name.
+   * @param key the name of the property
+   * @return the additional (undeclared) property with the specified name
+   */
+  public Fruit getAdditionalProperty(String key) {
+    if (this.additionalProperties == null) {
+        return null;
+    }
+    return this.additionalProperties.get(key);
+  }
+
+  /**
+   * Return true if this Drawing object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Drawing drawing = (Drawing) o;
+    return Objects.equals(this.mainShape, drawing.mainShape) &&
+        Objects.equals(this.shapeOrNull, drawing.shapeOrNull) &&
+        equalsNullable(this.nullableShape, drawing.nullableShape) &&
+        Objects.equals(this.shapes, drawing.shapes)&&
+        Objects.equals(this.additionalProperties, drawing.additionalProperties) &&
+        super.equals(o);
+  }
+
+  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(mainShape, shapeOrNull, hashCodeNullable(nullableShape), shapes, super.hashCode(), additionalProperties);
+  }
+
+  private static <T> int hashCodeNullable(JsonNullable<T> a) {
+    if (a == null) {
+      return 1;
+    }
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class Drawing {\n");
+    sb.append("    ").append(toIndentedString(super.toString())).append("\n");
+    sb.append("    mainShape: ").append(toIndentedString(mainShape)).append("\n");
+    sb.append("    shapeOrNull: ").append(toIndentedString(shapeOrNull)).append("\n");
+    sb.append("    nullableShape: ").append(toIndentedString(nullableShape)).append("\n");
+    sb.append("    shapes: ").append(toIndentedString(shapes)).append("\n");
+    sb.append("    additionalProperties: ").append(toIndentedString(additionalProperties)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `mainShape` to the URL query string
+    if (getMainShape() != null) {
+      joiner.add(getMainShape().toUrlQueryString(prefix + "mainShape" + suffix));
+    }
+
+    // add `shapeOrNull` to the URL query string
+    if (getShapeOrNull() != null) {
+      joiner.add(getShapeOrNull().toUrlQueryString(prefix + "shapeOrNull" + suffix));
+    }
+
+    // add `nullableShape` to the URL query string
+    if (getNullableShape() != null) {
+      joiner.add(getNullableShape().toUrlQueryString(prefix + "nullableShape" + suffix));
+    }
+
+    // add `shapes` to the URL query string
+    if (getShapes() != null) {
+      for (int i = 0; i < getShapes().size(); i++) {
+        if (getShapes().get(i) != null) {
+          joiner.add(getShapes().get(i).toUrlQueryString(String.format("%sshapes%s%s", prefix, suffix,
+          "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix))));
+        }
+      }
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java

@@ -43,6 +43,7 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
   EnumTest.JSON_PROPERTY_ENUM_STRING,
   EnumTest.JSON_PROPERTY_ENUM_STRING_REQUIRED,
   EnumTest.JSON_PROPERTY_ENUM_INTEGER,
+  EnumTest.JSON_PROPERTY_ENUM_INTEGER_ONLY,
   EnumTest.JSON_PROPERTY_ENUM_NUMBER,
   EnumTest.JSON_PROPERTY_OUTER_ENUM,
   EnumTest.JSON_PROPERTY_OUTER_ENUM_INTEGER,
@@ -169,6 +170,44 @@ public class EnumTest {
   public static final String JSON_PROPERTY_ENUM_INTEGER = "enum_integer";
   private EnumIntegerEnum enumInteger;
 
+  /**
+   * Gets or Sets enumIntegerOnly
+   */
+  public enum EnumIntegerOnlyEnum {
+    NUMBER_2(2),
+    
+    NUMBER_MINUS_2(-2);
+
+    private Integer value;
+
+    EnumIntegerOnlyEnum(Integer value) {
+      this.value = value;
+    }
+
+    @JsonValue
+    public Integer getValue() {
+      return value;
+    }
+
+    @Override
+    public String toString() {
+      return String.valueOf(value);
+    }
+
+    @JsonCreator
+    public static EnumIntegerOnlyEnum fromValue(Integer value) {
+      for (EnumIntegerOnlyEnum b : EnumIntegerOnlyEnum.values()) {
+        if (b.value.equals(value)) {
+          return b;
+        }
+      }
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
+    }
+  }
+
+  public static final String JSON_PROPERTY_ENUM_INTEGER_ONLY = "enum_integer_only";
+  private EnumIntegerOnlyEnum enumIntegerOnly;
+
   /**
    * Gets or Sets enumNumber
    */
@@ -297,6 +336,31 @@ public class EnumTest {
   }
 
 
+  public EnumTest enumIntegerOnly(EnumIntegerOnlyEnum enumIntegerOnly) {
+    this.enumIntegerOnly = enumIntegerOnly;
+    return this;
+  }
+
+   /**
+   * Get enumIntegerOnly
+   * @return enumIntegerOnly
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_ENUM_INTEGER_ONLY)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public EnumIntegerOnlyEnum getEnumIntegerOnly() {
+    return enumIntegerOnly;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_ENUM_INTEGER_ONLY)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setEnumIntegerOnly(EnumIntegerOnlyEnum enumIntegerOnly) {
+    this.enumIntegerOnly = enumIntegerOnly;
+  }
+
+
   public EnumTest enumNumber(EnumNumberEnum enumNumber) {
     this.enumNumber = enumNumber;
     return this;
@@ -445,6 +509,7 @@ public class EnumTest {
     return Objects.equals(this.enumString, enumTest.enumString) &&
         Objects.equals(this.enumStringRequired, enumTest.enumStringRequired) &&
         Objects.equals(this.enumInteger, enumTest.enumInteger) &&
+        Objects.equals(this.enumIntegerOnly, enumTest.enumIntegerOnly) &&
         Objects.equals(this.enumNumber, enumTest.enumNumber) &&
         equalsNullable(this.outerEnum, enumTest.outerEnum) &&
         Objects.equals(this.outerEnumInteger, enumTest.outerEnumInteger) &&
@@ -458,7 +523,7 @@ public class EnumTest {
 
   @Override
   public int hashCode() {
-    return Objects.hash(enumString, enumStringRequired, enumInteger, enumNumber, hashCodeNullable(outerEnum), outerEnumInteger, outerEnumDefaultValue, outerEnumIntegerDefaultValue);
+    return Objects.hash(enumString, enumStringRequired, enumInteger, enumIntegerOnly, enumNumber, hashCodeNullable(outerEnum), outerEnumInteger, outerEnumDefaultValue, outerEnumIntegerDefaultValue);
   }
 
   private static <T> int hashCodeNullable(JsonNullable<T> a) {
@@ -475,6 +540,7 @@ public class EnumTest {
     sb.append("    enumString: ").append(toIndentedString(enumString)).append("\n");
     sb.append("    enumStringRequired: ").append(toIndentedString(enumStringRequired)).append("\n");
     sb.append("    enumInteger: ").append(toIndentedString(enumInteger)).append("\n");
+    sb.append("    enumIntegerOnly: ").append(toIndentedString(enumIntegerOnly)).append("\n");
     sb.append("    enumNumber: ").append(toIndentedString(enumNumber)).append("\n");
     sb.append("    outerEnum: ").append(toIndentedString(outerEnum)).append("\n");
     sb.append("    outerEnumInteger: ").append(toIndentedString(outerEnumInteger)).append("\n");
@@ -542,6 +608,11 @@ public class EnumTest {
       joiner.add(String.format("%senum_integer%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getEnumInteger()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
     }
 
+    // add `enum_integer_only` to the URL query string
+    if (getEnumIntegerOnly() != null) {
+      joiner.add(String.format("%senum_integer_only%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getEnumIntegerOnly()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
     // add `enum_number` to the URL query string
     if (getEnumNumber() != null) {
       joiner.add(String.format("%senum_number%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getEnumNumber()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EquilateralTriangle.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * EquilateralTriangle
+ */
+@JsonPropertyOrder({
+  EquilateralTriangle.JSON_PROPERTY_SHAPE_TYPE,
+  EquilateralTriangle.JSON_PROPERTY_TRIANGLE_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class EquilateralTriangle {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public static final String JSON_PROPERTY_TRIANGLE_TYPE = "triangleType";
+  private String triangleType;
+
+  public EquilateralTriangle() { 
+  }
+
+  public EquilateralTriangle shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  public EquilateralTriangle triangleType(String triangleType) {
+    this.triangleType = triangleType;
+    return this;
+  }
+
+   /**
+   * Get triangleType
+   * @return triangleType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getTriangleType() {
+    return triangleType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setTriangleType(String triangleType) {
+    this.triangleType = triangleType;
+  }
+
+
+  /**
+   * Return true if this EquilateralTriangle object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    EquilateralTriangle equilateralTriangle = (EquilateralTriangle) o;
+    return Objects.equals(this.shapeType, equilateralTriangle.shapeType) &&
+        Objects.equals(this.triangleType, equilateralTriangle.triangleType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType, triangleType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class EquilateralTriangle {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("    triangleType: ").append(toIndentedString(triangleType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `triangleType` to the URL query string
+    if (getTriangleType() != null) {
+      joiner.add(String.format("%striangleType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getTriangleType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Fruit.java

@@ -0,0 +1,297 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.openapitools.client.model.Apple;
+import org.openapitools.client.model.Banana;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Fruit.FruitDeserializer.class)
+@JsonSerialize(using = Fruit.FruitSerializer.class)
+public class Fruit extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Fruit.class.getName());
+
+    public static class FruitSerializer extends StdSerializer<Fruit> {
+        public FruitSerializer(Class<Fruit> t) {
+            super(t);
+        }
+
+        public FruitSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Fruit value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class FruitDeserializer extends StdDeserializer<Fruit> {
+        public FruitDeserializer() {
+            this(Fruit.class);
+        }
+
+        public FruitDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Fruit deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize Apple
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Apple.class.equals(Integer.class) || Apple.class.equals(Long.class) || Apple.class.equals(Float.class) || Apple.class.equals(Double.class) || Apple.class.equals(Boolean.class) || Apple.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Apple.class.equals(Integer.class) || Apple.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Apple.class.equals(Float.class) || Apple.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Apple.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Apple.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Apple.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Apple'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Apple'", e);
+            }
+
+            // deserialize Banana
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Banana.class.equals(Integer.class) || Banana.class.equals(Long.class) || Banana.class.equals(Float.class) || Banana.class.equals(Double.class) || Banana.class.equals(Boolean.class) || Banana.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Banana.class.equals(Integer.class) || Banana.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Banana.class.equals(Float.class) || Banana.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Banana.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Banana.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Banana.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Banana'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Banana'", e);
+            }
+
+            if (match == 1) {
+                Fruit ret = new Fruit();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Fruit: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Fruit getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Fruit cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Fruit() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Fruit(Apple o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Fruit(Banana o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Apple", Apple.class);
+        schemas.put("Banana", Banana.class);
+        JSON.registerDescendants(Fruit.class, Collections.unmodifiableMap(schemas));
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Fruit.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * Apple, Banana
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Apple, Banana");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Apple, Banana
+     *
+     * @return The actual instance (Apple, Banana)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Apple`. If the actual instance is not `Apple`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Apple`
+     * @throws ClassCastException if the instance is not `Apple`
+     */
+    public Apple getApple() throws ClassCastException {
+        return (Apple)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Banana`. If the actual instance is not `Banana`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Banana`
+     * @throws ClassCastException if the instance is not `Banana`
+     */
+    public Banana getBanana() throws ClassCastException {
+        return (Banana)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof Apple) {
+        if (getActualInstance() != null) {
+          joiner.add(((Apple)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Banana) {
+        if (getActualInstance() != null) {
+          joiner.add(((Banana)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FruitReq.java

@@ -0,0 +1,297 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.openapitools.client.model.AppleReq;
+import org.openapitools.client.model.BananaReq;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = FruitReq.FruitReqDeserializer.class)
+@JsonSerialize(using = FruitReq.FruitReqSerializer.class)
+public class FruitReq extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(FruitReq.class.getName());
+
+    public static class FruitReqSerializer extends StdSerializer<FruitReq> {
+        public FruitReqSerializer(Class<FruitReq> t) {
+            super(t);
+        }
+
+        public FruitReqSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(FruitReq value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class FruitReqDeserializer extends StdDeserializer<FruitReq> {
+        public FruitReqDeserializer() {
+            this(FruitReq.class);
+        }
+
+        public FruitReqDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public FruitReq deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize AppleReq
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (AppleReq.class.equals(Integer.class) || AppleReq.class.equals(Long.class) || AppleReq.class.equals(Float.class) || AppleReq.class.equals(Double.class) || AppleReq.class.equals(Boolean.class) || AppleReq.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((AppleReq.class.equals(Integer.class) || AppleReq.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((AppleReq.class.equals(Float.class) || AppleReq.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (AppleReq.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (AppleReq.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(AppleReq.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'AppleReq'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'AppleReq'", e);
+            }
+
+            // deserialize BananaReq
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (BananaReq.class.equals(Integer.class) || BananaReq.class.equals(Long.class) || BananaReq.class.equals(Float.class) || BananaReq.class.equals(Double.class) || BananaReq.class.equals(Boolean.class) || BananaReq.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((BananaReq.class.equals(Integer.class) || BananaReq.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((BananaReq.class.equals(Float.class) || BananaReq.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (BananaReq.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (BananaReq.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(BananaReq.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'BananaReq'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'BananaReq'", e);
+            }
+
+            if (match == 1) {
+                FruitReq ret = new FruitReq();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for FruitReq: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public FruitReq getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "FruitReq cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public FruitReq() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public FruitReq(AppleReq o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public FruitReq(BananaReq o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("AppleReq", AppleReq.class);
+        schemas.put("BananaReq", BananaReq.class);
+        JSON.registerDescendants(FruitReq.class, Collections.unmodifiableMap(schemas));
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return FruitReq.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * AppleReq, BananaReq
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(AppleReq.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(BananaReq.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be AppleReq, BananaReq");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * AppleReq, BananaReq
+     *
+     * @return The actual instance (AppleReq, BananaReq)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `AppleReq`. If the actual instance is not `AppleReq`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `AppleReq`
+     * @throws ClassCastException if the instance is not `AppleReq`
+     */
+    public AppleReq getAppleReq() throws ClassCastException {
+        return (AppleReq)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `BananaReq`. If the actual instance is not `BananaReq`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `BananaReq`
+     * @throws ClassCastException if the instance is not `BananaReq`
+     */
+    public BananaReq getBananaReq() throws ClassCastException {
+        return (BananaReq)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof AppleReq) {
+        if (getActualInstance() != null) {
+          joiner.add(((AppleReq)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof BananaReq) {
+        if (getActualInstance() != null) {
+          joiner.add(((BananaReq)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GmFruit.java

@@ -0,0 +1,208 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.openapitools.client.model.Apple;
+import org.openapitools.client.model.Banana;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using=GmFruit.GmFruitDeserializer.class)
+@JsonSerialize(using = GmFruit.GmFruitSerializer.class)
+public class GmFruit extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(GmFruit.class.getName());
+
+    public static class GmFruitSerializer extends StdSerializer<GmFruit> {
+        public GmFruitSerializer(Class<GmFruit> t) {
+            super(t);
+        }
+
+        public GmFruitSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(GmFruit value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class GmFruitDeserializer extends StdDeserializer<GmFruit> {
+        public GmFruitDeserializer() {
+            this(GmFruit.class);
+        }
+
+        public GmFruitDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public GmFruit deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+
+            Object deserialized = null;
+            // deserialize Apple
+            try {
+                deserialized = tree.traverse(jp.getCodec()).readValueAs(Apple.class);
+                GmFruit ret = new GmFruit();
+                ret.setActualInstance(deserialized);
+                return ret;
+            } catch (Exception e) {
+                // deserialization failed, continue, log to help debugging
+                log.log(Level.FINER, "Input data does not match 'GmFruit'", e);
+            }
+
+            // deserialize Banana
+            try {
+                deserialized = tree.traverse(jp.getCodec()).readValueAs(Banana.class);
+                GmFruit ret = new GmFruit();
+                ret.setActualInstance(deserialized);
+                return ret;
+            } catch (Exception e) {
+                // deserialization failed, continue, log to help debugging
+                log.log(Level.FINER, "Input data does not match 'GmFruit'", e);
+            }
+
+            throw new IOException(String.format("Failed deserialization for GmFruit: no match found"));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public GmFruit getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "GmFruit cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in anyOf
+    public static final Map<String, Class<?>> schemas = new HashMap<String, Class<?>>();
+
+    public GmFruit() {
+        super("anyOf", Boolean.FALSE);
+    }
+
+    public GmFruit(Apple o) {
+        super("anyOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public GmFruit(Banana o) {
+        super("anyOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Apple", Apple.class);
+        schemas.put("Banana", Banana.class);
+        JSON.registerDescendants(GmFruit.class, Collections.unmodifiableMap(schemas));
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return GmFruit.schemas;
+    }
+
+    /**
+     * Set the instance that matches the anyOf child schema, check
+     * the instance parameter is valid against the anyOf child schemas:
+     * Apple, Banana
+     *
+     * It could be an instance of the 'anyOf' schemas.
+     * The anyOf child schemas may themselves be a composed schema (allOf, anyOf, anyOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Apple, Banana");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Apple, Banana
+     *
+     * @return The actual instance (Apple, Banana)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Apple`. If the actual instance is not `Apple`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Apple`
+     * @throws ClassCastException if the instance is not `Apple`
+     */
+    public Apple getApple() throws ClassCastException {
+        return (Apple)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Banana`. If the actual instance is not `Banana`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Banana`
+     * @throws ClassCastException if the instance is not `Banana`
+     */
+    public Banana getBanana() throws ClassCastException {
+        return (Banana)super.getActualInstance();
+    }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GrandparentAnimal.java

@@ -0,0 +1,174 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.ChildCat;
+import org.openapitools.client.model.ParentPet;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+import org.openapitools.client.JSON;
+/**
+ * GrandparentAnimal
+ */
+@JsonPropertyOrder({
+  GrandparentAnimal.JSON_PROPERTY_PET_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonIgnoreProperties(
+  value = "pet_type", // ignore manually set pet_type, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the pet_type to be set during deserialization
+)
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "pet_type", visible = true)
+@JsonSubTypes({
+  @JsonSubTypes.Type(value = ChildCat.class, name = "ChildCat"),
+  @JsonSubTypes.Type(value = ParentPet.class, name = "ParentPet"),
+})
+
+public class GrandparentAnimal {
+  public static final String JSON_PROPERTY_PET_TYPE = "pet_type";
+  private String petType;
+
+  public GrandparentAnimal() { 
+  }
+
+  public GrandparentAnimal petType(String petType) {
+    this.petType = petType;
+    return this;
+  }
+
+   /**
+   * Get petType
+   * @return petType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getPetType() {
+    return petType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_PET_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setPetType(String petType) {
+    this.petType = petType;
+  }
+
+
+  /**
+   * Return true if this GrandparentAnimal object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    GrandparentAnimal grandparentAnimal = (GrandparentAnimal) o;
+    return Objects.equals(this.petType, grandparentAnimal.petType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(petType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class GrandparentAnimal {\n");
+    sb.append("    petType: ").append(toIndentedString(petType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `pet_type` to the URL query string
+    if (getPetType() != null) {
+      joiner.add(String.format("%spet_type%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getPetType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+static {
+  // Initialize and register the discriminator mappings.
+  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  mappings.put("ChildCat", ChildCat.class);
+  mappings.put("ParentPet", ParentPet.class);
+  mappings.put("GrandparentAnimal", GrandparentAnimal.class);
+  JSON.registerDiscriminator(GrandparentAnimal.class, "pet_type", mappings);
+}
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * IsoscelesTriangle
+ */
+@JsonPropertyOrder({
+  IsoscelesTriangle.JSON_PROPERTY_SHAPE_TYPE,
+  IsoscelesTriangle.JSON_PROPERTY_TRIANGLE_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class IsoscelesTriangle {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public static final String JSON_PROPERTY_TRIANGLE_TYPE = "triangleType";
+  private String triangleType;
+
+  public IsoscelesTriangle() { 
+  }
+
+  public IsoscelesTriangle shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  public IsoscelesTriangle triangleType(String triangleType) {
+    this.triangleType = triangleType;
+    return this;
+  }
+
+   /**
+   * Get triangleType
+   * @return triangleType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getTriangleType() {
+    return triangleType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setTriangleType(String triangleType) {
+    this.triangleType = triangleType;
+  }
+
+
+  /**
+   * Return true if this IsoscelesTriangle object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    IsoscelesTriangle isoscelesTriangle = (IsoscelesTriangle) o;
+    return Objects.equals(this.shapeType, isoscelesTriangle.shapeType) &&
+        Objects.equals(this.triangleType, isoscelesTriangle.triangleType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType, triangleType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class IsoscelesTriangle {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("    triangleType: ").append(toIndentedString(triangleType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `triangleType` to the URL query string
+    if (getTriangleType() != null) {
+      joiner.add(String.format("%striangleType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getTriangleType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Mammal.java

@@ -0,0 +1,361 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.Pig;
+import org.openapitools.client.model.Whale;
+import org.openapitools.client.model.Zebra;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Mammal.MammalDeserializer.class)
+@JsonSerialize(using = Mammal.MammalSerializer.class)
+public class Mammal extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Mammal.class.getName());
+
+    public static class MammalSerializer extends StdSerializer<Mammal> {
+        public MammalSerializer(Class<Mammal> t) {
+            super(t);
+        }
+
+        public MammalSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Mammal value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class MammalDeserializer extends StdDeserializer<Mammal> {
+        public MammalDeserializer() {
+            this(Mammal.class);
+        }
+
+        public MammalDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Mammal deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize Pig
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Pig.class.equals(Integer.class) || Pig.class.equals(Long.class) || Pig.class.equals(Float.class) || Pig.class.equals(Double.class) || Pig.class.equals(Boolean.class) || Pig.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Pig.class.equals(Integer.class) || Pig.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Pig.class.equals(Float.class) || Pig.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Pig.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Pig.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Pig.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Pig'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Pig'", e);
+            }
+
+            // deserialize Whale
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Whale.class.equals(Integer.class) || Whale.class.equals(Long.class) || Whale.class.equals(Float.class) || Whale.class.equals(Double.class) || Whale.class.equals(Boolean.class) || Whale.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Whale.class.equals(Integer.class) || Whale.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Whale.class.equals(Float.class) || Whale.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Whale.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Whale.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Whale.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Whale'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Whale'", e);
+            }
+
+            // deserialize Zebra
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Zebra.class.equals(Integer.class) || Zebra.class.equals(Long.class) || Zebra.class.equals(Float.class) || Zebra.class.equals(Double.class) || Zebra.class.equals(Boolean.class) || Zebra.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Zebra.class.equals(Integer.class) || Zebra.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Zebra.class.equals(Float.class) || Zebra.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Zebra.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Zebra.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Zebra.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Zebra'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Zebra'", e);
+            }
+
+            if (match == 1) {
+                Mammal ret = new Mammal();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Mammal: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Mammal getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Mammal cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Mammal() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Mammal(Pig o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Mammal(Whale o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Mammal(Zebra o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Pig", Pig.class);
+        schemas.put("Whale", Whale.class);
+        schemas.put("Zebra", Zebra.class);
+        JSON.registerDescendants(Mammal.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("Pig", Pig.class);
+        mappings.put("whale", Whale.class);
+        mappings.put("zebra", Zebra.class);
+        mappings.put("mammal", Mammal.class);
+        JSON.registerDiscriminator(Mammal.class, "className", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Mammal.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * Pig, Whale, Zebra
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(Pig.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Whale.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Zebra.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Pig, Whale, Zebra");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Pig, Whale, Zebra
+     *
+     * @return The actual instance (Pig, Whale, Zebra)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Pig`. If the actual instance is not `Pig`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Pig`
+     * @throws ClassCastException if the instance is not `Pig`
+     */
+    public Pig getPig() throws ClassCastException {
+        return (Pig)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Whale`. If the actual instance is not `Whale`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Whale`
+     * @throws ClassCastException if the instance is not `Whale`
+     */
+    public Whale getWhale() throws ClassCastException {
+        return (Whale)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Zebra`. If the actual instance is not `Zebra`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Zebra`
+     * @throws ClassCastException if the instance is not `Zebra`
+     */
+    public Zebra getZebra() throws ClassCastException {
+        return (Zebra)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof Whale) {
+        if (getActualInstance() != null) {
+          joiner.add(((Whale)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Zebra) {
+        if (getActualInstance() != null) {
+          joiner.add(String.format("%sone_of_1%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getActualInstance()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Pig) {
+        if (getActualInstance() != null) {
+          joiner.add(((Pig)getActualInstance()).toUrlQueryString(prefix + "one_of_2" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableShape.java

@@ -0,0 +1,312 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = NullableShape.NullableShapeDeserializer.class)
+@JsonSerialize(using = NullableShape.NullableShapeSerializer.class)
+public class NullableShape extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(NullableShape.class.getName());
+
+    public static class NullableShapeSerializer extends StdSerializer<NullableShape> {
+        public NullableShapeSerializer(Class<NullableShape> t) {
+            super(t);
+        }
+
+        public NullableShapeSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(NullableShape value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class NullableShapeDeserializer extends StdDeserializer<NullableShape> {
+        public NullableShapeDeserializer() {
+            this(NullableShape.class);
+        }
+
+        public NullableShapeDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public NullableShape deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize Quadrilateral
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class) || Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class) || Quadrilateral.class.equals(Boolean.class) || Quadrilateral.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Quadrilateral.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Quadrilateral.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                        attemptParsing |= (token == JsonToken.VALUE_NULL);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Quadrilateral.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Quadrilateral'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Quadrilateral'", e);
+            }
+
+            // deserialize Triangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class) || Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class) || Triangle.class.equals(Boolean.class) || Triangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Triangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Triangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                        attemptParsing |= (token == JsonToken.VALUE_NULL);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Triangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Triangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Triangle'", e);
+            }
+
+            if (match == 1) {
+                NullableShape ret = new NullableShape();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for NullableShape: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public NullableShape getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            return null;
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public NullableShape() {
+        super("oneOf", Boolean.TRUE);
+    }
+
+    public NullableShape(Quadrilateral o) {
+        super("oneOf", Boolean.TRUE);
+        setActualInstance(o);
+    }
+
+    public NullableShape(Triangle o) {
+        super("oneOf", Boolean.TRUE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Quadrilateral", Quadrilateral.class);
+        schemas.put("Triangle", Triangle.class);
+        JSON.registerDescendants(NullableShape.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("Quadrilateral", Quadrilateral.class);
+        mappings.put("Triangle", Triangle.class);
+        mappings.put("NullableShape", NullableShape.class);
+        JSON.registerDiscriminator(NullableShape.class, "shapeType", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return NullableShape.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * Quadrilateral, Triangle
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (instance == null) {
+           super.setActualInstance(instance);
+           return;
+        }
+
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Quadrilateral, Triangle");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Quadrilateral, Triangle
+     *
+     * @return The actual instance (Quadrilateral, Triangle)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Quadrilateral`. If the actual instance is not `Quadrilateral`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Quadrilateral`
+     * @throws ClassCastException if the instance is not `Quadrilateral`
+     */
+    public Quadrilateral getQuadrilateral() throws ClassCastException {
+        return (Quadrilateral)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Triangle`. If the actual instance is not `Triangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Triangle`
+     * @throws ClassCastException if the instance is not `Triangle`
+     */
+    public Triangle getTriangle() throws ClassCastException {
+        return (Triangle)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof Triangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((Triangle)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Quadrilateral) {
+        if (getActualInstance() != null) {
+          joiner.add(((Quadrilateral)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ParentPet.java

@@ -0,0 +1,142 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.ChildCat;
+import org.openapitools.client.model.GrandparentAnimal;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+import org.openapitools.client.JSON;
+/**
+ * ParentPet
+ */
+@JsonPropertyOrder({
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonIgnoreProperties(
+  value = "pet_type", // ignore manually set pet_type, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the pet_type to be set during deserialization
+)
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "pet_type", visible = true)
+@JsonSubTypes({
+  @JsonSubTypes.Type(value = ChildCat.class, name = "ChildCat"),
+})
+
+public class ParentPet extends GrandparentAnimal {
+  public ParentPet() { 
+  }
+
+  /**
+   * Return true if this ParentPet object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    return super.equals(o);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(super.hashCode());
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ParentPet {\n");
+    sb.append("    ").append(toIndentedString(super.toString())).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `pet_type` to the URL query string
+    if (getPetType() != null) {
+      joiner.add(String.format("%spet_type%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getPetType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+static {
+  // Initialize and register the discriminator mappings.
+  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+  mappings.put("ChildCat", ChildCat.class);
+  mappings.put("ParentPet", ParentPet.class);
+  JSON.registerDiscriminator(ParentPet.class, "pet_type", mappings);
+}
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java

@@ -25,11 +25,8 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import java.util.ArrayList;
-import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.Set;
 import org.openapitools.client.model.Category;
 import org.openapitools.client.model.Tag;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
@@ -58,7 +55,7 @@ public class Pet {
   private String name;
 
   public static final String JSON_PROPERTY_PHOTO_URLS = "photoUrls";
-  private Set<String> photoUrls = new LinkedHashSet<>();
+  private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
   private List<Tag> tags = null;
@@ -181,7 +178,7 @@ public class Pet {
   }
 
 
-  public Pet photoUrls(Set<String> photoUrls) {
+  public Pet photoUrls(List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -199,15 +196,14 @@ public class Pet {
   @JsonProperty(JSON_PROPERTY_PHOTO_URLS)
   @JsonInclude(value = JsonInclude.Include.ALWAYS)
 
-  public Set<String> getPhotoUrls() {
+  public List<String> getPhotoUrls() {
     return photoUrls;
   }
 
 
-  @JsonDeserialize(as = LinkedHashSet.class)
   @JsonProperty(JSON_PROPERTY_PHOTO_URLS)
   @JsonInclude(value = JsonInclude.Include.ALWAYS)
-  public void setPhotoUrls(Set<String> photoUrls) {
+  public void setPhotoUrls(List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
@@ -369,13 +365,11 @@ public class Pet {
 
     // add `photoUrls` to the URL query string
     if (getPhotoUrls() != null) {
-      int i = 0;
+      for (int i = 0; i < getPhotoUrls().size(); i++) {
-      for (String _item : getPhotoUrls()) {
         joiner.add(String.format("%sphotoUrls%s%s=%s", prefix, suffix,
             "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
-            URLEncoder.encode(String.valueOf(_item), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+            URLEncoder.encode(String.valueOf(getPhotoUrls().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
       }
-      i++;
     }
 
     // add `tags` to the URL query string

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pig.java

@@ -0,0 +1,305 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.BasquePig;
+import org.openapitools.client.model.DanishPig;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Pig.PigDeserializer.class)
+@JsonSerialize(using = Pig.PigSerializer.class)
+public class Pig extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Pig.class.getName());
+
+    public static class PigSerializer extends StdSerializer<Pig> {
+        public PigSerializer(Class<Pig> t) {
+            super(t);
+        }
+
+        public PigSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Pig value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class PigDeserializer extends StdDeserializer<Pig> {
+        public PigDeserializer() {
+            this(Pig.class);
+        }
+
+        public PigDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Pig deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize BasquePig
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (BasquePig.class.equals(Integer.class) || BasquePig.class.equals(Long.class) || BasquePig.class.equals(Float.class) || BasquePig.class.equals(Double.class) || BasquePig.class.equals(Boolean.class) || BasquePig.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((BasquePig.class.equals(Integer.class) || BasquePig.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((BasquePig.class.equals(Float.class) || BasquePig.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (BasquePig.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (BasquePig.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(BasquePig.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'BasquePig'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'BasquePig'", e);
+            }
+
+            // deserialize DanishPig
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (DanishPig.class.equals(Integer.class) || DanishPig.class.equals(Long.class) || DanishPig.class.equals(Float.class) || DanishPig.class.equals(Double.class) || DanishPig.class.equals(Boolean.class) || DanishPig.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((DanishPig.class.equals(Integer.class) || DanishPig.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((DanishPig.class.equals(Float.class) || DanishPig.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (DanishPig.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (DanishPig.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(DanishPig.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'DanishPig'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'DanishPig'", e);
+            }
+
+            if (match == 1) {
+                Pig ret = new Pig();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Pig: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Pig getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Pig cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Pig() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Pig(BasquePig o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Pig(DanishPig o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("BasquePig", BasquePig.class);
+        schemas.put("DanishPig", DanishPig.class);
+        JSON.registerDescendants(Pig.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("BasquePig", BasquePig.class);
+        mappings.put("DanishPig", DanishPig.class);
+        mappings.put("Pig", Pig.class);
+        JSON.registerDiscriminator(Pig.class, "className", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Pig.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * BasquePig, DanishPig
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(BasquePig.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(DanishPig.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be BasquePig, DanishPig");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * BasquePig, DanishPig
+     *
+     * @return The actual instance (BasquePig, DanishPig)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `BasquePig`. If the actual instance is not `BasquePig`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `BasquePig`
+     * @throws ClassCastException if the instance is not `BasquePig`
+     */
+    public BasquePig getBasquePig() throws ClassCastException {
+        return (BasquePig)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `DanishPig`. If the actual instance is not `DanishPig`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `DanishPig`
+     * @throws ClassCastException if the instance is not `DanishPig`
+     */
+    public DanishPig getDanishPig() throws ClassCastException {
+        return (DanishPig)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof BasquePig) {
+        if (getActualInstance() != null) {
+          joiner.add(((BasquePig)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof DanishPig) {
+        if (getActualInstance() != null) {
+          joiner.add(((DanishPig)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Quadrilateral.java

@@ -0,0 +1,305 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.ComplexQuadrilateral;
+import org.openapitools.client.model.SimpleQuadrilateral;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Quadrilateral.QuadrilateralDeserializer.class)
+@JsonSerialize(using = Quadrilateral.QuadrilateralSerializer.class)
+public class Quadrilateral extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Quadrilateral.class.getName());
+
+    public static class QuadrilateralSerializer extends StdSerializer<Quadrilateral> {
+        public QuadrilateralSerializer(Class<Quadrilateral> t) {
+            super(t);
+        }
+
+        public QuadrilateralSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Quadrilateral value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class QuadrilateralDeserializer extends StdDeserializer<Quadrilateral> {
+        public QuadrilateralDeserializer() {
+            this(Quadrilateral.class);
+        }
+
+        public QuadrilateralDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Quadrilateral deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize ComplexQuadrilateral
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (ComplexQuadrilateral.class.equals(Integer.class) || ComplexQuadrilateral.class.equals(Long.class) || ComplexQuadrilateral.class.equals(Float.class) || ComplexQuadrilateral.class.equals(Double.class) || ComplexQuadrilateral.class.equals(Boolean.class) || ComplexQuadrilateral.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((ComplexQuadrilateral.class.equals(Integer.class) || ComplexQuadrilateral.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((ComplexQuadrilateral.class.equals(Float.class) || ComplexQuadrilateral.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (ComplexQuadrilateral.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (ComplexQuadrilateral.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(ComplexQuadrilateral.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'ComplexQuadrilateral'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'ComplexQuadrilateral'", e);
+            }
+
+            // deserialize SimpleQuadrilateral
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (SimpleQuadrilateral.class.equals(Integer.class) || SimpleQuadrilateral.class.equals(Long.class) || SimpleQuadrilateral.class.equals(Float.class) || SimpleQuadrilateral.class.equals(Double.class) || SimpleQuadrilateral.class.equals(Boolean.class) || SimpleQuadrilateral.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((SimpleQuadrilateral.class.equals(Integer.class) || SimpleQuadrilateral.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((SimpleQuadrilateral.class.equals(Float.class) || SimpleQuadrilateral.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (SimpleQuadrilateral.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (SimpleQuadrilateral.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(SimpleQuadrilateral.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'SimpleQuadrilateral'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'SimpleQuadrilateral'", e);
+            }
+
+            if (match == 1) {
+                Quadrilateral ret = new Quadrilateral();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Quadrilateral: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Quadrilateral getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Quadrilateral cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Quadrilateral() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Quadrilateral(ComplexQuadrilateral o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Quadrilateral(SimpleQuadrilateral o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("ComplexQuadrilateral", ComplexQuadrilateral.class);
+        schemas.put("SimpleQuadrilateral", SimpleQuadrilateral.class);
+        JSON.registerDescendants(Quadrilateral.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("ComplexQuadrilateral", ComplexQuadrilateral.class);
+        mappings.put("SimpleQuadrilateral", SimpleQuadrilateral.class);
+        mappings.put("Quadrilateral", Quadrilateral.class);
+        JSON.registerDiscriminator(Quadrilateral.class, "quadrilateralType", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Quadrilateral.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * ComplexQuadrilateral, SimpleQuadrilateral
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(ComplexQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(SimpleQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be ComplexQuadrilateral, SimpleQuadrilateral");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * ComplexQuadrilateral, SimpleQuadrilateral
+     *
+     * @return The actual instance (ComplexQuadrilateral, SimpleQuadrilateral)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `ComplexQuadrilateral`. If the actual instance is not `ComplexQuadrilateral`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `ComplexQuadrilateral`
+     * @throws ClassCastException if the instance is not `ComplexQuadrilateral`
+     */
+    public ComplexQuadrilateral getComplexQuadrilateral() throws ClassCastException {
+        return (ComplexQuadrilateral)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `SimpleQuadrilateral`. If the actual instance is not `SimpleQuadrilateral`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `SimpleQuadrilateral`
+     * @throws ClassCastException if the instance is not `SimpleQuadrilateral`
+     */
+    public SimpleQuadrilateral getSimpleQuadrilateral() throws ClassCastException {
+        return (SimpleQuadrilateral)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof SimpleQuadrilateral) {
+        if (getActualInstance() != null) {
+          joiner.add(((SimpleQuadrilateral)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof ComplexQuadrilateral) {
+        if (getActualInstance() != null) {
+          joiner.add(((ComplexQuadrilateral)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java

@@ -0,0 +1,150 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * QuadrilateralInterface
+ */
+@JsonPropertyOrder({
+  QuadrilateralInterface.JSON_PROPERTY_QUADRILATERAL_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class QuadrilateralInterface {
+  public static final String JSON_PROPERTY_QUADRILATERAL_TYPE = "quadrilateralType";
+  private String quadrilateralType;
+
+  public QuadrilateralInterface() { 
+  }
+
+  public QuadrilateralInterface quadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+    return this;
+  }
+
+   /**
+   * Get quadrilateralType
+   * @return quadrilateralType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getQuadrilateralType() {
+    return quadrilateralType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setQuadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+  }
+
+
+  /**
+   * Return true if this QuadrilateralInterface object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    QuadrilateralInterface quadrilateralInterface = (QuadrilateralInterface) o;
+    return Objects.equals(this.quadrilateralType, quadrilateralInterface.quadrilateralType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(quadrilateralType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class QuadrilateralInterface {\n");
+    sb.append("    quadrilateralType: ").append(toIndentedString(quadrilateralType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `quadrilateralType` to the URL query string
+    if (getQuadrilateralType() != null) {
+      joiner.add(String.format("%squadrilateralType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getQuadrilateralType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ScaleneTriangle.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * ScaleneTriangle
+ */
+@JsonPropertyOrder({
+  ScaleneTriangle.JSON_PROPERTY_SHAPE_TYPE,
+  ScaleneTriangle.JSON_PROPERTY_TRIANGLE_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ScaleneTriangle {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public static final String JSON_PROPERTY_TRIANGLE_TYPE = "triangleType";
+  private String triangleType;
+
+  public ScaleneTriangle() { 
+  }
+
+  public ScaleneTriangle shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  public ScaleneTriangle triangleType(String triangleType) {
+    this.triangleType = triangleType;
+    return this;
+  }
+
+   /**
+   * Get triangleType
+   * @return triangleType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getTriangleType() {
+    return triangleType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setTriangleType(String triangleType) {
+    this.triangleType = triangleType;
+  }
+
+
+  /**
+   * Return true if this ScaleneTriangle object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ScaleneTriangle scaleneTriangle = (ScaleneTriangle) o;
+    return Objects.equals(this.shapeType, scaleneTriangle.shapeType) &&
+        Objects.equals(this.triangleType, scaleneTriangle.triangleType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType, triangleType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ScaleneTriangle {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("    triangleType: ").append(toIndentedString(triangleType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `triangleType` to the URL query string
+    if (getTriangleType() != null) {
+      joiner.add(String.format("%striangleType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getTriangleType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Shape.java

@@ -0,0 +1,305 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Shape.ShapeDeserializer.class)
+@JsonSerialize(using = Shape.ShapeSerializer.class)
+public class Shape extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Shape.class.getName());
+
+    public static class ShapeSerializer extends StdSerializer<Shape> {
+        public ShapeSerializer(Class<Shape> t) {
+            super(t);
+        }
+
+        public ShapeSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Shape value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class ShapeDeserializer extends StdDeserializer<Shape> {
+        public ShapeDeserializer() {
+            this(Shape.class);
+        }
+
+        public ShapeDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Shape deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize Quadrilateral
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class) || Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class) || Quadrilateral.class.equals(Boolean.class) || Quadrilateral.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Quadrilateral.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Quadrilateral.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Quadrilateral.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Quadrilateral'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Quadrilateral'", e);
+            }
+
+            // deserialize Triangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class) || Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class) || Triangle.class.equals(Boolean.class) || Triangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Triangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Triangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Triangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Triangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Triangle'", e);
+            }
+
+            if (match == 1) {
+                Shape ret = new Shape();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Shape: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Shape getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Shape cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Shape() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Shape(Quadrilateral o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Shape(Triangle o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Quadrilateral", Quadrilateral.class);
+        schemas.put("Triangle", Triangle.class);
+        JSON.registerDescendants(Shape.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("Quadrilateral", Quadrilateral.class);
+        mappings.put("Triangle", Triangle.class);
+        mappings.put("Shape", Shape.class);
+        JSON.registerDiscriminator(Shape.class, "shapeType", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Shape.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * Quadrilateral, Triangle
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Quadrilateral, Triangle");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Quadrilateral, Triangle
+     *
+     * @return The actual instance (Quadrilateral, Triangle)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Quadrilateral`. If the actual instance is not `Quadrilateral`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Quadrilateral`
+     * @throws ClassCastException if the instance is not `Quadrilateral`
+     */
+    public Quadrilateral getQuadrilateral() throws ClassCastException {
+        return (Quadrilateral)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Triangle`. If the actual instance is not `Triangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Triangle`
+     * @throws ClassCastException if the instance is not `Triangle`
+     */
+    public Triangle getTriangle() throws ClassCastException {
+        return (Triangle)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof Triangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((Triangle)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Quadrilateral) {
+        if (getActualInstance() != null) {
+          joiner.add(((Quadrilateral)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeInterface.java

@@ -0,0 +1,150 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * ShapeInterface
+ */
+@JsonPropertyOrder({
+  ShapeInterface.JSON_PROPERTY_SHAPE_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ShapeInterface {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public ShapeInterface() { 
+  }
+
+  public ShapeInterface shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  /**
+   * Return true if this ShapeInterface object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ShapeInterface shapeInterface = (ShapeInterface) o;
+    return Objects.equals(this.shapeType, shapeInterface.shapeType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ShapeInterface {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeOrNull.java

@@ -0,0 +1,305 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.Quadrilateral;
+import org.openapitools.client.model.Triangle;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = ShapeOrNull.ShapeOrNullDeserializer.class)
+@JsonSerialize(using = ShapeOrNull.ShapeOrNullSerializer.class)
+public class ShapeOrNull extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(ShapeOrNull.class.getName());
+
+    public static class ShapeOrNullSerializer extends StdSerializer<ShapeOrNull> {
+        public ShapeOrNullSerializer(Class<ShapeOrNull> t) {
+            super(t);
+        }
+
+        public ShapeOrNullSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(ShapeOrNull value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class ShapeOrNullDeserializer extends StdDeserializer<ShapeOrNull> {
+        public ShapeOrNullDeserializer() {
+            this(ShapeOrNull.class);
+        }
+
+        public ShapeOrNullDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public ShapeOrNull deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize Quadrilateral
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class) || Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class) || Quadrilateral.class.equals(Boolean.class) || Quadrilateral.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Quadrilateral.class.equals(Integer.class) || Quadrilateral.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Quadrilateral.class.equals(Float.class) || Quadrilateral.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Quadrilateral.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Quadrilateral.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Quadrilateral.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Quadrilateral'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Quadrilateral'", e);
+            }
+
+            // deserialize Triangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class) || Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class) || Triangle.class.equals(Boolean.class) || Triangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((Triangle.class.equals(Integer.class) || Triangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((Triangle.class.equals(Float.class) || Triangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (Triangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (Triangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(Triangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'Triangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'Triangle'", e);
+            }
+
+            if (match == 1) {
+                ShapeOrNull ret = new ShapeOrNull();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for ShapeOrNull: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public ShapeOrNull getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "ShapeOrNull cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public ShapeOrNull() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public ShapeOrNull(Quadrilateral o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public ShapeOrNull(Triangle o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("Quadrilateral", Quadrilateral.class);
+        schemas.put("Triangle", Triangle.class);
+        JSON.registerDescendants(ShapeOrNull.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("Quadrilateral", Quadrilateral.class);
+        mappings.put("Triangle", Triangle.class);
+        mappings.put("ShapeOrNull", ShapeOrNull.class);
+        JSON.registerDiscriminator(ShapeOrNull.class, "shapeType", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return ShapeOrNull.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * Quadrilateral, Triangle
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be Quadrilateral, Triangle");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * Quadrilateral, Triangle
+     *
+     * @return The actual instance (Quadrilateral, Triangle)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Quadrilateral`. If the actual instance is not `Quadrilateral`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Quadrilateral`
+     * @throws ClassCastException if the instance is not `Quadrilateral`
+     */
+    public Quadrilateral getQuadrilateral() throws ClassCastException {
+        return (Quadrilateral)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `Triangle`. If the actual instance is not `Triangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `Triangle`
+     * @throws ClassCastException if the instance is not `Triangle`
+     */
+    public Triangle getTriangle() throws ClassCastException {
+        return (Triangle)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof Triangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((Triangle)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof Quadrilateral) {
+        if (getActualInstance() != null) {
+          joiner.add(((Quadrilateral)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java

@@ -0,0 +1,186 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * SimpleQuadrilateral
+ */
+@JsonPropertyOrder({
+  SimpleQuadrilateral.JSON_PROPERTY_SHAPE_TYPE,
+  SimpleQuadrilateral.JSON_PROPERTY_QUADRILATERAL_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class SimpleQuadrilateral {
+  public static final String JSON_PROPERTY_SHAPE_TYPE = "shapeType";
+  private String shapeType;
+
+  public static final String JSON_PROPERTY_QUADRILATERAL_TYPE = "quadrilateralType";
+  private String quadrilateralType;
+
+  public SimpleQuadrilateral() { 
+  }
+
+  public SimpleQuadrilateral shapeType(String shapeType) {
+    this.shapeType = shapeType;
+    return this;
+  }
+
+   /**
+   * Get shapeType
+   * @return shapeType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getShapeType() {
+    return shapeType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SHAPE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setShapeType(String shapeType) {
+    this.shapeType = shapeType;
+  }
+
+
+  public SimpleQuadrilateral quadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+    return this;
+  }
+
+   /**
+   * Get quadrilateralType
+   * @return quadrilateralType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getQuadrilateralType() {
+    return quadrilateralType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_QUADRILATERAL_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setQuadrilateralType(String quadrilateralType) {
+    this.quadrilateralType = quadrilateralType;
+  }
+
+
+  /**
+   * Return true if this SimpleQuadrilateral object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    SimpleQuadrilateral simpleQuadrilateral = (SimpleQuadrilateral) o;
+    return Objects.equals(this.shapeType, simpleQuadrilateral.shapeType) &&
+        Objects.equals(this.quadrilateralType, simpleQuadrilateral.quadrilateralType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(shapeType, quadrilateralType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class SimpleQuadrilateral {\n");
+    sb.append("    shapeType: ").append(toIndentedString(shapeType)).append("\n");
+    sb.append("    quadrilateralType: ").append(toIndentedString(quadrilateralType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `shapeType` to the URL query string
+    if (getShapeType() != null) {
+      joiner.add(String.format("%sshapeType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getShapeType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `quadrilateralType` to the URL query string
+    if (getQuadrilateralType() != null) {
+      joiner.add(String.format("%squadrilateralType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getQuadrilateralType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java

@@ -32,13 +32,17 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
  * SpecialModelName
  */
 @JsonPropertyOrder({
-  SpecialModelName.JSON_PROPERTY_$_SPECIAL_PROPERTY_NAME
+  SpecialModelName.JSON_PROPERTY_$_SPECIAL_PROPERTY_NAME,
+  SpecialModelName.JSON_PROPERTY_SPECIAL_MODEL_NAME
 })
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class SpecialModelName {
   public static final String JSON_PROPERTY_$_SPECIAL_PROPERTY_NAME = "$special[property.name]";
   private Long $specialPropertyName;
 
+  public static final String JSON_PROPERTY_SPECIAL_MODEL_NAME = "_special_model.name_";
+  private String specialModelName;
+
   public SpecialModelName() { 
   }
 
@@ -67,6 +71,31 @@ public class SpecialModelName {
   }
 
 
+  public SpecialModelName specialModelName(String specialModelName) {
+    this.specialModelName = specialModelName;
+    return this;
+  }
+
+   /**
+   * Get specialModelName
+   * @return specialModelName
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_SPECIAL_MODEL_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public String getSpecialModelName() {
+    return specialModelName;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_SPECIAL_MODEL_NAME)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setSpecialModelName(String specialModelName) {
+    this.specialModelName = specialModelName;
+  }
+
+
   /**
    * Return true if this _special_model.name_ object is equal to o.
    */
@@ -79,12 +108,13 @@ public class SpecialModelName {
       return false;
     }
     SpecialModelName specialModelName = (SpecialModelName) o;
-    return Objects.equals(this.$specialPropertyName, specialModelName.$specialPropertyName);
+    return Objects.equals(this.$specialPropertyName, specialModelName.$specialPropertyName) &&
+        Objects.equals(this.specialModelName, specialModelName.specialModelName);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash($specialPropertyName);
+    return Objects.hash($specialPropertyName, specialModelName);
   }
 
   @Override
@@ -92,6 +122,7 @@ public class SpecialModelName {
     StringBuilder sb = new StringBuilder();
     sb.append("class SpecialModelName {\n");
     sb.append("    $specialPropertyName: ").append(toIndentedString($specialPropertyName)).append("\n");
+    sb.append("    specialModelName: ").append(toIndentedString(specialModelName)).append("\n");
     sb.append("}");
     return sb.toString();
   }
@@ -144,6 +175,11 @@ public class SpecialModelName {
       joiner.add(String.format("%s$special[property.name]%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(get$SpecialPropertyName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
     }
 
+    // add `_special_model.name_` to the URL query string
+    if (getSpecialModelName() != null) {
+      joiner.add(String.format("%s_special_model.name_%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getSpecialModelName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
     return joiner.toString();
   }
 }

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Triangle.java

@@ -0,0 +1,361 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.EquilateralTriangle;
+import org.openapitools.client.model.IsoscelesTriangle;
+import org.openapitools.client.model.ScaleneTriangle;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+@JsonDeserialize(using = Triangle.TriangleDeserializer.class)
+@JsonSerialize(using = Triangle.TriangleSerializer.class)
+public class Triangle extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(Triangle.class.getName());
+
+    public static class TriangleSerializer extends StdSerializer<Triangle> {
+        public TriangleSerializer(Class<Triangle> t) {
+            super(t);
+        }
+
+        public TriangleSerializer() {
+            this(null);
+        }
+
+        @Override
+        public void serialize(Triangle value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
+            jgen.writeObject(value.getActualInstance());
+        }
+    }
+
+    public static class TriangleDeserializer extends StdDeserializer<Triangle> {
+        public TriangleDeserializer() {
+            this(Triangle.class);
+        }
+
+        public TriangleDeserializer(Class<?> vc) {
+            super(vc);
+        }
+
+        @Override
+        public Triangle deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+            JsonNode tree = jp.readValueAsTree();
+            Object deserialized = null;
+            boolean typeCoercion = ctxt.isEnabled(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+            int match = 0;
+            JsonToken token = tree.traverse(jp.getCodec()).nextToken();
+            // deserialize EquilateralTriangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (EquilateralTriangle.class.equals(Integer.class) || EquilateralTriangle.class.equals(Long.class) || EquilateralTriangle.class.equals(Float.class) || EquilateralTriangle.class.equals(Double.class) || EquilateralTriangle.class.equals(Boolean.class) || EquilateralTriangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((EquilateralTriangle.class.equals(Integer.class) || EquilateralTriangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((EquilateralTriangle.class.equals(Float.class) || EquilateralTriangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (EquilateralTriangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (EquilateralTriangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(EquilateralTriangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'EquilateralTriangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'EquilateralTriangle'", e);
+            }
+
+            // deserialize IsoscelesTriangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (IsoscelesTriangle.class.equals(Integer.class) || IsoscelesTriangle.class.equals(Long.class) || IsoscelesTriangle.class.equals(Float.class) || IsoscelesTriangle.class.equals(Double.class) || IsoscelesTriangle.class.equals(Boolean.class) || IsoscelesTriangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((IsoscelesTriangle.class.equals(Integer.class) || IsoscelesTriangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((IsoscelesTriangle.class.equals(Float.class) || IsoscelesTriangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (IsoscelesTriangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (IsoscelesTriangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(IsoscelesTriangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'IsoscelesTriangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'IsoscelesTriangle'", e);
+            }
+
+            // deserialize ScaleneTriangle
+            try {
+                boolean attemptParsing = true;
+                // ensure that we respect type coercion as set on the client ObjectMapper
+                if (ScaleneTriangle.class.equals(Integer.class) || ScaleneTriangle.class.equals(Long.class) || ScaleneTriangle.class.equals(Float.class) || ScaleneTriangle.class.equals(Double.class) || ScaleneTriangle.class.equals(Boolean.class) || ScaleneTriangle.class.equals(String.class)) {
+                    attemptParsing = typeCoercion;
+                    if (!attemptParsing) {
+                        attemptParsing |= ((ScaleneTriangle.class.equals(Integer.class) || ScaleneTriangle.class.equals(Long.class)) && token == JsonToken.VALUE_NUMBER_INT);
+                        attemptParsing |= ((ScaleneTriangle.class.equals(Float.class) || ScaleneTriangle.class.equals(Double.class)) && token == JsonToken.VALUE_NUMBER_FLOAT);
+                        attemptParsing |= (ScaleneTriangle.class.equals(Boolean.class) && (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE));
+                        attemptParsing |= (ScaleneTriangle.class.equals(String.class) && token == JsonToken.VALUE_STRING);
+                    }
+                }
+                if (attemptParsing) {
+                    deserialized = tree.traverse(jp.getCodec()).readValueAs(ScaleneTriangle.class);
+                    // TODO: there is no validation against JSON schema constraints
+                    // (min, max, enum, pattern...), this does not perform a strict JSON
+                    // validation, which means the 'match' count may be higher than it should be.
+                    match++;
+                    log.log(Level.FINER, "Input data matches schema 'ScaleneTriangle'");
+                }
+            } catch (Exception e) {
+                // deserialization failed, continue
+                log.log(Level.FINER, "Input data does not match schema 'ScaleneTriangle'", e);
+            }
+
+            if (match == 1) {
+                Triangle ret = new Triangle();
+                ret.setActualInstance(deserialized);
+                return ret;
+            }
+            throw new IOException(String.format("Failed deserialization for Triangle: %d classes match result, expected 1", match));
+        }
+
+        /**
+         * Handle deserialization of the 'null' value.
+         */
+        @Override
+        public Triangle getNullValue(DeserializationContext ctxt) throws JsonMappingException {
+            throw new JsonMappingException(ctxt.getParser(), "Triangle cannot be null");
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<>();
+
+    public Triangle() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public Triangle(EquilateralTriangle o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Triangle(IsoscelesTriangle o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    public Triangle(ScaleneTriangle o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("EquilateralTriangle", EquilateralTriangle.class);
+        schemas.put("IsoscelesTriangle", IsoscelesTriangle.class);
+        schemas.put("ScaleneTriangle", ScaleneTriangle.class);
+        JSON.registerDescendants(Triangle.class, Collections.unmodifiableMap(schemas));
+        // Initialize and register the discriminator mappings.
+        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        mappings.put("EquilateralTriangle", EquilateralTriangle.class);
+        mappings.put("IsoscelesTriangle", IsoscelesTriangle.class);
+        mappings.put("ScaleneTriangle", ScaleneTriangle.class);
+        mappings.put("Triangle", Triangle.class);
+        JSON.registerDiscriminator(Triangle.class, "triangleType", mappings);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return Triangle.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * EquilateralTriangle, IsoscelesTriangle, ScaleneTriangle
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     * The oneOf child schemas may themselves be a composed schema (allOf, anyOf, oneOf).
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (JSON.isInstanceOf(EquilateralTriangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(IsoscelesTriangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        if (JSON.isInstanceOf(ScaleneTriangle.class, instance, new HashSet<Class<?>>())) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be EquilateralTriangle, IsoscelesTriangle, ScaleneTriangle");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * EquilateralTriangle, IsoscelesTriangle, ScaleneTriangle
+     *
+     * @return The actual instance (EquilateralTriangle, IsoscelesTriangle, ScaleneTriangle)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `EquilateralTriangle`. If the actual instance is not `EquilateralTriangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `EquilateralTriangle`
+     * @throws ClassCastException if the instance is not `EquilateralTriangle`
+     */
+    public EquilateralTriangle getEquilateralTriangle() throws ClassCastException {
+        return (EquilateralTriangle)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `IsoscelesTriangle`. If the actual instance is not `IsoscelesTriangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `IsoscelesTriangle`
+     * @throws ClassCastException if the instance is not `IsoscelesTriangle`
+     */
+    public IsoscelesTriangle getIsoscelesTriangle() throws ClassCastException {
+        return (IsoscelesTriangle)super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `ScaleneTriangle`. If the actual instance is not `ScaleneTriangle`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `ScaleneTriangle`
+     * @throws ClassCastException if the instance is not `ScaleneTriangle`
+     */
+    public ScaleneTriangle getScaleneTriangle() throws ClassCastException {
+        return (ScaleneTriangle)super.getActualInstance();
+    }
+
+
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    if (getActualInstance() instanceof EquilateralTriangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((EquilateralTriangle)getActualInstance()).toUrlQueryString(prefix + "one_of_0" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof IsoscelesTriangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((IsoscelesTriangle)getActualInstance()).toUrlQueryString(prefix + "one_of_1" + suffix));
+        }
+        return joiner.toString();
+    }
+    if (getActualInstance() instanceof ScaleneTriangle) {
+        if (getActualInstance() != null) {
+          joiner.add(((ScaleneTriangle)getActualInstance()).toUrlQueryString(prefix + "one_of_2" + suffix));
+        }
+        return joiner.toString();
+    }
+    return null;
+  }
+
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TriangleInterface.java

@@ -0,0 +1,150 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * TriangleInterface
+ */
+@JsonPropertyOrder({
+  TriangleInterface.JSON_PROPERTY_TRIANGLE_TYPE
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class TriangleInterface {
+  public static final String JSON_PROPERTY_TRIANGLE_TYPE = "triangleType";
+  private String triangleType;
+
+  public TriangleInterface() { 
+  }
+
+  public TriangleInterface triangleType(String triangleType) {
+    this.triangleType = triangleType;
+    return this;
+  }
+
+   /**
+   * Get triangleType
+   * @return triangleType
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getTriangleType() {
+    return triangleType;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_TRIANGLE_TYPE)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setTriangleType(String triangleType) {
+    this.triangleType = triangleType;
+  }
+
+
+  /**
+   * Return true if this TriangleInterface object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    TriangleInterface triangleInterface = (TriangleInterface) o;
+    return Objects.equals(this.triangleType, triangleInterface.triangleType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(triangleType);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class TriangleInterface {\n");
+    sb.append("    triangleType: ").append(toIndentedString(triangleType)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `triangleType` to the URL query string
+    if (getTriangleType() != null) {
+      joiner.add(String.format("%striangleType%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getTriangleType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java

@@ -25,6 +25,10 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.jackson.nullable.JsonNullable;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 
@@ -39,7 +43,11 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
   User.JSON_PROPERTY_EMAIL,
   User.JSON_PROPERTY_PASSWORD,
   User.JSON_PROPERTY_PHONE,
-  User.JSON_PROPERTY_USER_STATUS
+  User.JSON_PROPERTY_USER_STATUS,
+  User.JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS,
+  User.JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE,
+  User.JSON_PROPERTY_ANY_TYPE_PROP,
+  User.JSON_PROPERTY_ANY_TYPE_PROP_NULLABLE
 })
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class User {
@@ -67,6 +75,18 @@ public class User {
   public static final String JSON_PROPERTY_USER_STATUS = "userStatus";
   private Integer userStatus;
 
+  public static final String JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS = "objectWithNoDeclaredProps";
+  private Object objectWithNoDeclaredProps;
+
+  public static final String JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE = "objectWithNoDeclaredPropsNullable";
+  private JsonNullable<Object> objectWithNoDeclaredPropsNullable = JsonNullable.<Object>undefined();
+
+  public static final String JSON_PROPERTY_ANY_TYPE_PROP = "anyTypeProp";
+  private JsonNullable<Object> anyTypeProp = JsonNullable.<Object>of(null);
+
+  public static final String JSON_PROPERTY_ANY_TYPE_PROP_NULLABLE = "anyTypePropNullable";
+  private JsonNullable<Object> anyTypePropNullable = JsonNullable.<Object>of(null);
+
   public User() { 
   }
 
@@ -270,6 +290,130 @@ public class User {
   }
 
 
+  public User objectWithNoDeclaredProps(Object objectWithNoDeclaredProps) {
+    this.objectWithNoDeclaredProps = objectWithNoDeclaredProps;
+    return this;
+  }
+
+   /**
+   * test code generation for objects Value must be a map of strings to values. It cannot be the &#39;null&#39; value.
+   * @return objectWithNoDeclaredProps
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Object getObjectWithNoDeclaredProps() {
+    return objectWithNoDeclaredProps;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setObjectWithNoDeclaredProps(Object objectWithNoDeclaredProps) {
+    this.objectWithNoDeclaredProps = objectWithNoDeclaredProps;
+  }
+
+
+  public User objectWithNoDeclaredPropsNullable(Object objectWithNoDeclaredPropsNullable) {
+    this.objectWithNoDeclaredPropsNullable = JsonNullable.<Object>of(objectWithNoDeclaredPropsNullable);
+    return this;
+  }
+
+   /**
+   * test code generation for nullable objects. Value must be a map of strings to values or the &#39;null&#39; value.
+   * @return objectWithNoDeclaredPropsNullable
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public Object getObjectWithNoDeclaredPropsNullable() {
+        return objectWithNoDeclaredPropsNullable.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<Object> getObjectWithNoDeclaredPropsNullable_JsonNullable() {
+    return objectWithNoDeclaredPropsNullable;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE)
+  public void setObjectWithNoDeclaredPropsNullable_JsonNullable(JsonNullable<Object> objectWithNoDeclaredPropsNullable) {
+    this.objectWithNoDeclaredPropsNullable = objectWithNoDeclaredPropsNullable;
+  }
+
+  public void setObjectWithNoDeclaredPropsNullable(Object objectWithNoDeclaredPropsNullable) {
+    this.objectWithNoDeclaredPropsNullable = JsonNullable.<Object>of(objectWithNoDeclaredPropsNullable);
+  }
+
+
+  public User anyTypeProp(Object anyTypeProp) {
+    this.anyTypeProp = JsonNullable.<Object>of(anyTypeProp);
+    return this;
+  }
+
+   /**
+   * test code generation for any type Here the &#39;type&#39; attribute is not specified, which means the value can be anything, including the null value, string, number, boolean, array or object. See https://github.com/OAI/OpenAPI-Specification/issues/1389
+   * @return anyTypeProp
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public Object getAnyTypeProp() {
+        return anyTypeProp.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_ANY_TYPE_PROP)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<Object> getAnyTypeProp_JsonNullable() {
+    return anyTypeProp;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_ANY_TYPE_PROP)
+  public void setAnyTypeProp_JsonNullable(JsonNullable<Object> anyTypeProp) {
+    this.anyTypeProp = anyTypeProp;
+  }
+
+  public void setAnyTypeProp(Object anyTypeProp) {
+    this.anyTypeProp = JsonNullable.<Object>of(anyTypeProp);
+  }
+
+
+  public User anyTypePropNullable(Object anyTypePropNullable) {
+    this.anyTypePropNullable = JsonNullable.<Object>of(anyTypePropNullable);
+    return this;
+  }
+
+   /**
+   * test code generation for any type Here the &#39;type&#39; attribute is not specified, which means the value can be anything, including the null value, string, number, boolean, array or object. The &#39;nullable&#39; attribute does not change the allowed values.
+   * @return anyTypePropNullable
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public Object getAnyTypePropNullable() {
+        return anyTypePropNullable.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_ANY_TYPE_PROP_NULLABLE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<Object> getAnyTypePropNullable_JsonNullable() {
+    return anyTypePropNullable;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_ANY_TYPE_PROP_NULLABLE)
+  public void setAnyTypePropNullable_JsonNullable(JsonNullable<Object> anyTypePropNullable) {
+    this.anyTypePropNullable = anyTypePropNullable;
+  }
+
+  public void setAnyTypePropNullable(Object anyTypePropNullable) {
+    this.anyTypePropNullable = JsonNullable.<Object>of(anyTypePropNullable);
+  }
+
+
   /**
    * Return true if this User object is equal to o.
    */
@@ -289,12 +433,27 @@ public class User {
         Objects.equals(this.email, user.email) &&
         Objects.equals(this.password, user.password) &&
         Objects.equals(this.phone, user.phone) &&
-        Objects.equals(this.userStatus, user.userStatus);
+        Objects.equals(this.userStatus, user.userStatus) &&
+        Objects.equals(this.objectWithNoDeclaredProps, user.objectWithNoDeclaredProps) &&
+        equalsNullable(this.objectWithNoDeclaredPropsNullable, user.objectWithNoDeclaredPropsNullable) &&
+        equalsNullable(this.anyTypeProp, user.anyTypeProp) &&
+        equalsNullable(this.anyTypePropNullable, user.anyTypePropNullable);
+  }
+
+  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(id, username, firstName, lastName, email, password, phone, userStatus);
+    return Objects.hash(id, username, firstName, lastName, email, password, phone, userStatus, objectWithNoDeclaredProps, hashCodeNullable(objectWithNoDeclaredPropsNullable), hashCodeNullable(anyTypeProp), hashCodeNullable(anyTypePropNullable));
+  }
+
+  private static <T> int hashCodeNullable(JsonNullable<T> a) {
+    if (a == null) {
+      return 1;
+    }
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
@@ -309,6 +468,10 @@ public class User {
     sb.append("    password: ").append(toIndentedString(password)).append("\n");
     sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
     sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
+    sb.append("    objectWithNoDeclaredProps: ").append(toIndentedString(objectWithNoDeclaredProps)).append("\n");
+    sb.append("    objectWithNoDeclaredPropsNullable: ").append(toIndentedString(objectWithNoDeclaredPropsNullable)).append("\n");
+    sb.append("    anyTypeProp: ").append(toIndentedString(anyTypeProp)).append("\n");
+    sb.append("    anyTypePropNullable: ").append(toIndentedString(anyTypePropNullable)).append("\n");
     sb.append("}");
     return sb.toString();
   }
@@ -396,6 +559,26 @@ public class User {
       joiner.add(String.format("%suserStatus%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getUserStatus()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
     }
 
+    // add `objectWithNoDeclaredProps` to the URL query string
+    if (getObjectWithNoDeclaredProps() != null) {
+      joiner.add(String.format("%sobjectWithNoDeclaredProps%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getObjectWithNoDeclaredProps()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `objectWithNoDeclaredPropsNullable` to the URL query string
+    if (getObjectWithNoDeclaredPropsNullable() != null) {
+      joiner.add(String.format("%sobjectWithNoDeclaredPropsNullable%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getObjectWithNoDeclaredPropsNullable()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `anyTypeProp` to the URL query string
+    if (getAnyTypeProp() != null) {
+      joiner.add(String.format("%sanyTypeProp%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getAnyTypeProp()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `anyTypePropNullable` to the URL query string
+    if (getAnyTypePropNullable() != null) {
+      joiner.add(String.format("%sanyTypePropNullable%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getAnyTypePropNullable()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
     return joiner.toString();
   }
 }

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Whale.java

@@ -0,0 +1,222 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * Whale
+ */
+@JsonPropertyOrder({
+  Whale.JSON_PROPERTY_HAS_BALEEN,
+  Whale.JSON_PROPERTY_HAS_TEETH,
+  Whale.JSON_PROPERTY_CLASS_NAME
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Whale {
+  public static final String JSON_PROPERTY_HAS_BALEEN = "hasBaleen";
+  private Boolean hasBaleen;
+
+  public static final String JSON_PROPERTY_HAS_TEETH = "hasTeeth";
+  private Boolean hasTeeth;
+
+  public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  private String className;
+
+  public Whale() { 
+  }
+
+  public Whale hasBaleen(Boolean hasBaleen) {
+    this.hasBaleen = hasBaleen;
+    return this;
+  }
+
+   /**
+   * Get hasBaleen
+   * @return hasBaleen
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_HAS_BALEEN)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Boolean getHasBaleen() {
+    return hasBaleen;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_HAS_BALEEN)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setHasBaleen(Boolean hasBaleen) {
+    this.hasBaleen = hasBaleen;
+  }
+
+
+  public Whale hasTeeth(Boolean hasTeeth) {
+    this.hasTeeth = hasTeeth;
+    return this;
+  }
+
+   /**
+   * Get hasTeeth
+   * @return hasTeeth
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_HAS_TEETH)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public Boolean getHasTeeth() {
+    return hasTeeth;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_HAS_TEETH)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setHasTeeth(Boolean hasTeeth) {
+    this.hasTeeth = hasTeeth;
+  }
+
+
+  public Whale className(String className) {
+    this.className = className;
+    return this;
+  }
+
+   /**
+   * Get className
+   * @return className
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getClassName() {
+    return className;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setClassName(String className) {
+    this.className = className;
+  }
+
+
+  /**
+   * Return true if this whale object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Whale whale = (Whale) o;
+    return Objects.equals(this.hasBaleen, whale.hasBaleen) &&
+        Objects.equals(this.hasTeeth, whale.hasTeeth) &&
+        Objects.equals(this.className, whale.className);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(hasBaleen, hasTeeth, className);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class Whale {\n");
+    sb.append("    hasBaleen: ").append(toIndentedString(hasBaleen)).append("\n");
+    sb.append("    hasTeeth: ").append(toIndentedString(hasTeeth)).append("\n");
+    sb.append("    className: ").append(toIndentedString(className)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `hasBaleen` to the URL query string
+    if (getHasBaleen() != null) {
+      joiner.add(String.format("%shasBaleen%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getHasBaleen()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `hasTeeth` to the URL query string
+    if (getHasTeeth() != null) {
+      joiner.add(String.format("%shasTeeth%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getHasTeeth()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `className` to the URL query string
+    if (getClassName() != null) {
+      joiner.add(String.format("%sclassName%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Zebra.java

@@ -0,0 +1,276 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import java.util.Map;
+import java.util.HashMap;
+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 com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.HashMap;
+import java.util.Map;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+
+/**
+ * Zebra
+ */
+@JsonPropertyOrder({
+  Zebra.JSON_PROPERTY_TYPE,
+  Zebra.JSON_PROPERTY_CLASS_NAME
+})
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Zebra extends HashMap<String, Object> {
+  /**
+   * Gets or Sets type
+   */
+  public enum TypeEnum {
+    PLAINS("plains"),
+    
+    MOUNTAIN("mountain"),
+    
+    GREVYS("grevys");
+
+    private String value;
+
+    TypeEnum(String value) {
+      this.value = value;
+    }
+
+    @JsonValue
+    public String getValue() {
+      return value;
+    }
+
+    @Override
+    public String toString() {
+      return String.valueOf(value);
+    }
+
+    @JsonCreator
+    public static TypeEnum fromValue(String value) {
+      for (TypeEnum b : TypeEnum.values()) {
+        if (b.value.equals(value)) {
+          return b;
+        }
+      }
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
+    }
+  }
+
+  public static final String JSON_PROPERTY_TYPE = "type";
+  private TypeEnum type;
+
+  public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  private String className;
+
+  public Zebra() { 
+  }
+
+  public Zebra type(TypeEnum type) {
+    this.type = type;
+    return this;
+  }
+
+   /**
+   * Get type
+   * @return type
+  **/
+  @javax.annotation.Nullable
+  @JsonProperty(JSON_PROPERTY_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public TypeEnum getType() {
+    return type;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_TYPE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setType(TypeEnum type) {
+    this.type = type;
+  }
+
+
+  public Zebra className(String className) {
+    this.className = className;
+    return this;
+  }
+
+   /**
+   * Get className
+   * @return className
+  **/
+  @javax.annotation.Nonnull
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+
+  public String getClassName() {
+    return className;
+  }
+
+
+  @JsonProperty(JSON_PROPERTY_CLASS_NAME)
+  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  public void setClassName(String className) {
+    this.className = className;
+  }
+
+  /**
+   * A container for additional, undeclared properties.
+   * This is a holder for any undeclared properties as specified with
+   * the 'additionalProperties' keyword in the OAS document.
+   */
+  private Map<String, Object> additionalProperties;
+
+  /**
+   * Set the additional (undeclared) property with the specified name and value.
+   * If the property does not already exist, create it otherwise replace it.
+   * @param key the name of the property
+   * @param value the value of the property
+   * @return self reference
+   */
+  @JsonAnySetter
+  public Zebra putAdditionalProperty(String key, Object value) {
+    if (this.additionalProperties == null) {
+        this.additionalProperties = new HashMap<String, Object>();
+    }
+    this.additionalProperties.put(key, value);
+    return this;
+  }
+
+  /**
+   * Return the additional (undeclared) properties.
+   * @return the additional (undeclared) properties
+   */
+  @JsonAnyGetter
+  public Map<String, Object> getAdditionalProperties() {
+    return additionalProperties;
+  }
+
+  /**
+   * Return the additional (undeclared) property with the specified name.
+   * @param key the name of the property
+   * @return the additional (undeclared) property with the specified name
+   */
+  public Object getAdditionalProperty(String key) {
+    if (this.additionalProperties == null) {
+        return null;
+    }
+    return this.additionalProperties.get(key);
+  }
+
+  /**
+   * Return true if this zebra object is equal to o.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Zebra zebra = (Zebra) o;
+    return Objects.equals(this.type, zebra.type) &&
+        Objects.equals(this.className, zebra.className)&&
+        Objects.equals(this.additionalProperties, zebra.additionalProperties) &&
+        super.equals(o);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(type, className, super.hashCode(), additionalProperties);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class Zebra {\n");
+    sb.append("    ").append(toIndentedString(super.toString())).append("\n");
+    sb.append("    type: ").append(toIndentedString(type)).append("\n");
+    sb.append("    className: ").append(toIndentedString(className)).append("\n");
+    sb.append("    additionalProperties: ").append(toIndentedString(additionalProperties)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @return URL query string
+   */
+  public String toUrlQueryString() {
+    return toUrlQueryString(null);
+  }
+
+  /**
+   * Convert the instance into URL query string.
+   *
+   * @param prefix prefix of the query string
+   * @return URL query string
+   */
+  public String toUrlQueryString(String prefix) {
+    String suffix = "";
+    String containerSuffix = "";
+    String containerPrefix = "";
+    if (prefix == null) {
+      // style=form, explode=true, e.g. /pet?name=cat&type=manx
+      prefix = "";
+    } else {
+      // deepObject style e.g. /pet?id[name]=cat&id[type]=manx
+      prefix = prefix + "[";
+      suffix = "]";
+      containerSuffix = "]";
+      containerPrefix = "[";
+    }
+
+    StringJoiner joiner = new StringJoiner("&");
+
+    // add `type` to the URL query string
+    if (getType() != null) {
+      joiner.add(String.format("%stype%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getType()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    // add `className` to the URL query string
+    if (getClassName() != null) {
+      joiner.add(String.format("%sclassName%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getClassName()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+    }
+
+    return joiner.toString();
+  }
+}
+

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/api/FakeApiTest.java

@@ -16,15 +16,13 @@ package org.openapitools.client.api;
 import org.openapitools.client.ApiException;
 import java.math.BigDecimal;
 import org.openapitools.client.model.Client;
-import org.openapitools.client.model.EnumClass;
 import java.io.File;
 import org.openapitools.client.model.FileSchemaTestClass;
 import org.openapitools.client.model.HealthCheckResult;
 import java.time.LocalDate;
 import java.time.OffsetDateTime;
 import org.openapitools.client.model.OuterComposite;
-import org.openapitools.client.model.OuterObjectWithEnumProperty;
+import org.openapitools.client.model.OuterEnum;
-import org.openapitools.client.model.Pet;
 import org.openapitools.client.model.User;
 import org.junit.Test;
 import org.junit.Ignore;
@@ -62,25 +60,6 @@ public class FakeApiTest {
         // TODO: test validations
     }
     
-    /**
-     * test http signature authentication
-     *
-     * 
-     *
-     * @throws ApiException
-     *          if the Api call fails
-     */
-    @Test
-    public void fakeHttpSignatureTestTest() throws ApiException {
-        Pet pet = null;
-        String query1 = null;
-        String header1 = null;
-        
-        CompletableFuture<Void> response = api.fakeHttpSignatureTest(pet, query1, header1);
-        
-        // TODO: test validations
-    }
-    
     /**
      * 
      *
@@ -150,18 +129,17 @@ public class FakeApiTest {
     }
     
     /**
-     * 
+     * Array of Enums
      *
-     * Test serialization of enum (int) properties with examples
+     * 
      *
      * @throws ApiException
      *          if the Api call fails
      */
     @Test
-    public void fakePropertyEnumIntegerSerializeTest() throws ApiException {
+    public void getArrayOfEnumsTest() throws ApiException {
-        OuterObjectWithEnumProperty outerObjectWithEnumProperty = null;
+        CompletableFuture<List<OuterEnum>> response = 
-        CompletableFuture<OuterObjectWithEnumProperty> response = 
+        api.getArrayOfEnums();
-        api.fakePropertyEnumIntegerSerialize(outerObjectWithEnumProperty);
         
         // TODO: test validations
     }
@@ -169,24 +147,7 @@ public class FakeApiTest {
     /**
      * 
      *
-     * For this test, the body has to be a binary file.
+     * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
-     *
-     * @throws ApiException
-     *          if the Api call fails
-     */
-    @Test
-    public void testBodyWithBinaryTest() throws ApiException {
-        File body = null;
-        
-        CompletableFuture<Void> response = api.testBodyWithBinary(body);
-        
-        // TODO: test validations
-    }
-    
-    /**
-     * 
-     *
-     * For this test, the body for this request must reference a schema named &#x60;File&#x60;.
      *
      * @throws ApiException
      *          if the Api call fails
@@ -281,11 +242,10 @@ public class FakeApiTest {
         String enumQueryString = null;
         Integer enumQueryInteger = null;
         Double enumQueryDouble = null;
-        List<EnumClass> enumQueryModelArray = null;
         List<String> enumFormStringArray = null;
         String enumFormString = null;
         
-        CompletableFuture<Void> response = api.testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumQueryModelArray, enumFormStringArray, enumFormString);
+        CompletableFuture<Void> response = api.testEnumParameters(enumHeaderStringArray, enumHeaderString, enumQueryStringArray, enumQueryString, enumQueryInteger, enumQueryDouble, enumFormStringArray, enumFormString);
         
         // TODO: test validations
     }
@@ -371,10 +331,8 @@ public class FakeApiTest {
         List<String> http = null;
         List<String> url = null;
         List<String> context = null;
-        String allowEmpty = null;
-        Map<String, String> language = null;
         
-        CompletableFuture<Void> response = api.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context, allowEmpty, language);
+        CompletableFuture<Void> response = api.testQueryParameterCollectionFormat(pipe, ioutil, http, url, context);
         
         // TODO: test validations
     }

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/api/PetApiTest.java

@@ -17,7 +17,6 @@ import org.openapitools.client.ApiException;
 import java.io.File;
 import org.openapitools.client.model.ModelApiResponse;
 import org.openapitools.client.model.Pet;
-import java.util.Set;
 import org.junit.Test;
 import org.junit.Ignore;
 
@@ -100,8 +99,8 @@ public class PetApiTest {
      */
     @Test
     public void findPetsByTagsTest() throws ApiException {
-        Set<String> tags = null;
+        List<String> tags = null;
-        CompletableFuture<Set<Pet>> response = 
+        CompletableFuture<List<Pet>> response = 
         api.findPetsByTags(tags);
         
         // TODO: test validations

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/AppleReqTest.java

@@ -0,0 +1,56 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for AppleReq
+ */
+public class AppleReqTest {
+    private final AppleReq model = new AppleReq();
+
+    /**
+     * Model tests for AppleReq
+     */
+    @Test
+    public void testAppleReq() {
+        // TODO: test AppleReq
+    }
+
+    /**
+     * Test the property 'cultivar'
+     */
+    @Test
+    public void cultivarTest() {
+        // TODO: test cultivar
+    }
+
+    /**
+     * Test the property 'mealy'
+     */
+    @Test
+    public void mealyTest() {
+        // TODO: test mealy
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/AppleTest.java

@@ -0,0 +1,56 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for Apple
+ */
+public class AppleTest {
+    private final Apple model = new Apple();
+
+    /**
+     * Model tests for Apple
+     */
+    @Test
+    public void testApple() {
+        // TODO: test Apple
+    }
+
+    /**
+     * Test the property 'cultivar'
+     */
+    @Test
+    public void cultivarTest() {
+        // TODO: test cultivar
+    }
+
+    /**
+     * Test the property 'origin'
+     */
+    @Test
+    public void originTest() {
+        // TODO: test origin
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/BananaReqTest.java

@@ -0,0 +1,57 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for BananaReq
+ */
+public class BananaReqTest {
+    private final BananaReq model = new BananaReq();
+
+    /**
+     * Model tests for BananaReq
+     */
+    @Test
+    public void testBananaReq() {
+        // TODO: test BananaReq
+    }
+
+    /**
+     * Test the property 'lengthCm'
+     */
+    @Test
+    public void lengthCmTest() {
+        // TODO: test lengthCm
+    }
+
+    /**
+     * Test the property 'sweet'
+     */
+    @Test
+    public void sweetTest() {
+        // TODO: test sweet
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/BananaTest.java

@@ -0,0 +1,49 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for Banana
+ */
+public class BananaTest {
+    private final Banana model = new Banana();
+
+    /**
+     * Model tests for Banana
+     */
+    @Test
+    public void testBanana() {
+        // TODO: test Banana
+    }
+
+    /**
+     * Test the property 'lengthCm'
+     */
+    @Test
+    public void lengthCmTest() {
+        // TODO: test lengthCm
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/BasquePigTest.java

@@ -0,0 +1,48 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for BasquePig
+ */
+public class BasquePigTest {
+    private final BasquePig model = new BasquePig();
+
+    /**
+     * Model tests for BasquePig
+     */
+    @Test
+    public void testBasquePig() {
+        // TODO: test BasquePig
+    }
+
+    /**
+     * Test the property 'className'
+     */
+    @Test
+    public void classNameTest() {
+        // TODO: test className
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/ChildCatAllOfTest.java

@@ -0,0 +1,58 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.Set;
+import java.util.HashSet;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for ChildCatAllOf
+ */
+public class ChildCatAllOfTest {
+    private final ChildCatAllOf model = new ChildCatAllOf();
+
+    /**
+     * Model tests for ChildCatAllOf
+     */
+    @Test
+    public void testChildCatAllOf() {
+        // TODO: test ChildCatAllOf
+    }
+
+    /**
+     * Test the property 'name'
+     */
+    @Test
+    public void nameTest() {
+        // TODO: test name
+    }
+
+    /**
+     * Test the property 'petType'
+     */
+    @Test
+    public void petTypeTest() {
+        // TODO: test petType
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/ChildCatTest.java

@@ -0,0 +1,62 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.openapitools.client.model.ParentPet;
+import java.util.Set;
+import java.util.HashSet;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for ChildCat
+ */
+public class ChildCatTest {
+    private final ChildCat model = new ChildCat();
+
+    /**
+     * Model tests for ChildCat
+     */
+    @Test
+    public void testChildCat() {
+        // TODO: test ChildCat
+    }
+
+    /**
+     * Test the property 'petType'
+     */
+    @Test
+    public void petTypeTest() {
+        // TODO: test petType
+    }
+
+    /**
+     * Test the property 'name'
+     */
+    @Test
+    public void nameTest() {
+        // TODO: test name
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/ComplexQuadrilateralTest.java

@@ -0,0 +1,56 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for ComplexQuadrilateral
+ */
+public class ComplexQuadrilateralTest {
+    private final ComplexQuadrilateral model = new ComplexQuadrilateral();
+
+    /**
+     * Model tests for ComplexQuadrilateral
+     */
+    @Test
+    public void testComplexQuadrilateral() {
+        // TODO: test ComplexQuadrilateral
+    }
+
+    /**
+     * Test the property 'shapeType'
+     */
+    @Test
+    public void shapeTypeTest() {
+        // TODO: test shapeType
+    }
+
+    /**
+     * Test the property 'quadrilateralType'
+     */
+    @Test
+    public void quadrilateralTypeTest() {
+        // TODO: test quadrilateralType
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/DanishPigTest.java

@@ -0,0 +1,48 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for DanishPig
+ */
+public class DanishPigTest {
+    private final DanishPig model = new DanishPig();
+
+    /**
+     * Model tests for DanishPig
+     */
+    @Test
+    public void testDanishPig() {
+        // TODO: test DanishPig
+    }
+
+    /**
+     * Test the property 'className'
+     */
+    @Test
+    public void classNameTest() {
+        // TODO: test className
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/DrawingTest.java

@@ -0,0 +1,84 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.openapitools.client.model.Fruit;
+import org.openapitools.client.model.NullableShape;
+import org.openapitools.client.model.Shape;
+import org.openapitools.client.model.ShapeOrNull;
+import org.openapitools.jackson.nullable.JsonNullable;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.util.NoSuchElementException;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for Drawing
+ */
+public class DrawingTest {
+    private final Drawing model = new Drawing();
+
+    /**
+     * Model tests for Drawing
+     */
+    @Test
+    public void testDrawing() {
+        // TODO: test Drawing
+    }
+
+    /**
+     * Test the property 'mainShape'
+     */
+    @Test
+    public void mainShapeTest() {
+        // TODO: test mainShape
+    }
+
+    /**
+     * Test the property 'shapeOrNull'
+     */
+    @Test
+    public void shapeOrNullTest() {
+        // TODO: test shapeOrNull
+    }
+
+    /**
+     * Test the property 'nullableShape'
+     */
+    @Test
+    public void nullableShapeTest() {
+        // TODO: test nullableShape
+    }
+
+    /**
+     * Test the property 'shapes'
+     */
+    @Test
+    public void shapesTest() {
+        // TODO: test shapes
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/EquilateralTriangleTest.java

@@ -0,0 +1,56 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for EquilateralTriangle
+ */
+public class EquilateralTriangleTest {
+    private final EquilateralTriangle model = new EquilateralTriangle();
+
+    /**
+     * Model tests for EquilateralTriangle
+     */
+    @Test
+    public void testEquilateralTriangle() {
+        // TODO: test EquilateralTriangle
+    }
+
+    /**
+     * Test the property 'shapeType'
+     */
+    @Test
+    public void shapeTypeTest() {
+        // TODO: test shapeType
+    }
+
+    /**
+     * Test the property 'triangleType'
+     */
+    @Test
+    public void triangleTypeTest() {
+        // TODO: test triangleType
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/FruitReqTest.java

@@ -0,0 +1,75 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.openapitools.client.model.AppleReq;
+import org.openapitools.client.model.BananaReq;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for FruitReq
+ */
+public class FruitReqTest {
+    private final FruitReq model = new FruitReq();
+
+    /**
+     * Model tests for FruitReq
+     */
+    @Test
+    public void testFruitReq() {
+        // TODO: test FruitReq
+    }
+
+    /**
+     * Test the property 'cultivar'
+     */
+    @Test
+    public void cultivarTest() {
+        // TODO: test cultivar
+    }
+
+    /**
+     * Test the property 'mealy'
+     */
+    @Test
+    public void mealyTest() {
+        // TODO: test mealy
+    }
+
+    /**
+     * Test the property 'lengthCm'
+     */
+    @Test
+    public void lengthCmTest() {
+        // TODO: test lengthCm
+    }
+
+    /**
+     * Test the property 'sweet'
+     */
+    @Test
+    public void sweetTest() {
+        // TODO: test sweet
+    }
+
+}

samples/client/petstore/java/native-async/src/test/java/org/openapitools/client/model/FruitTest.java

@@ -0,0 +1,67 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.math.BigDecimal;
+import org.openapitools.client.model.Apple;
+import org.openapitools.client.model.Banana;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for Fruit
+ */
+public class FruitTest {
+    private final Fruit model = new Fruit();
+
+    /**
+     * Model tests for Fruit
+     */
+    @Test
+    public void testFruit() {
+        // TODO: test Fruit
+    }
+
+    /**
+     * Test the property 'cultivar'
+     */
+    @Test
+    public void cultivarTest() {
+        // TODO: test cultivar
+    }
+
+    /**
+     * Test the property 'origin'
+     */
+    @Test
+    public void originTest() {
+        // TODO: test origin
+    }
+
+    /**
+     * Test the property 'lengthCm'
+     */
+    @Test
+    public void lengthCmTest() {
+        // TODO: test lengthCm
+    }
+
+}