diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index b7d31d9fce53..f791d39762f2 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -818,7 +818,7 @@ public void postProcessParameter(CodegenParameter parameter) {
     @Override
     @SuppressWarnings("unused")
     public void preprocessOpenAPI(OpenAPI openAPI) {
-        if (useOneOfInterfaces) {
+        if (useOneOfInterfaces && openAPI.getComponents() != null) {
             // we process the openapi schema here to find oneOf schemas and create interface models for them
             Map<String, Schema> schemas = new HashMap<String, Schema>(openAPI.getComponents().getSchemas());
             if (schemas == null) {
@@ -2418,9 +2418,6 @@ public CodegenModel fromModel(String name, Schema schema) {
         m.classFilename = toModelFilename(name);
         m.modelJson = Json.pretty(schema);
         m.externalDocumentation = schema.getExternalDocs();
-        if (schema.getExtensions() != null && !schema.getExtensions().isEmpty()) {
-            m.getVendorExtensions().putAll(schema.getExtensions());
-        }
         m.isAlias = (typeAliases.containsKey(name)
                 || isAliasOfSimpleTypes(schema)); // check if the unaliased schema is an alias of simple OAS types
         m.setDiscriminator(createDiscriminator(name, schema, this.openAPI));
@@ -2428,6 +2425,28 @@ public CodegenModel fromModel(String name, Schema schema) {
             m.addDiscriminatorMappedModelsImports();
         }
 
+        if (schema.getExtensions() != null && !schema.getExtensions().isEmpty()) {
+            m.getVendorExtensions().putAll(schema.getExtensions());
+            if (ModelUtils.isComposedSchema(schema)
+                    && m.discriminator == null
+                    && schema.getExtensions().containsKey("x-one-of-name")) {
+                boolean isDeductionCase = true;
+                List<String> deductionModelNames = new ArrayList<>();
+                for (Schema modelSchema : ((ComposedSchema) schema).getOneOf()) {
+                    if (modelSchema.get$ref() == null) {
+                        isDeductionCase = false;
+                        break;
+                    }
+                    String modelName = ModelUtils.getSimpleRef(modelSchema.get$ref());
+                    deductionModelNames.add(toModelName(modelName));
+                }
+                if (isDeductionCase) {
+                    m.vendorExtensions.put("x-deduction", true);
+                    m.vendorExtensions.put("x-deduction-model-names", deductionModelNames);
+                }
+            }
+        }
+
         if (schema.getDeprecated() != null) {
             m.isDeprecated = schema.getDeprecated();
         }
@@ -3165,7 +3184,7 @@ protected CodegenDiscriminator createDiscriminator(String schemaName, Schema sch
             }
         }
         // if there are composed oneOf/anyOf schemas, add them to this discriminator
-        if (ModelUtils.isComposedSchema(schema) && !this.getLegacyDiscriminatorBehavior()) {
+        if (ModelUtils.isComposedSchema(schema)) {
             List<MappedModel> otherDescendants = getOneOfAnyOfDescendants(schemaName, discPropName, (ComposedSchema) schema, openAPI);
             for (MappedModel otherDescendant : otherDescendants) {
                 if (!uniqueDescendants.contains(otherDescendant)) {
@@ -4177,6 +4196,11 @@ public CodegenResponse fromResponse(String responseCode, ApiResponse response) {
         } else { // no model/alias defined
             responseSchema = ModelUtils.getSchemaFromResponse(response);
         }
+
+        if (!ModelUtils.isSchemaOneOfConsistsOfCustomTypes(this.openAPI, responseSchema)) {
+            responseSchema = new Schema();
+        }
+
         r.schema = responseSchema;
         if (responseSchema != null) {
             ModelUtils.syncValidationProperties(responseSchema, r);
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index 748e30815490..a6007654bc84 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -43,6 +43,7 @@
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
+import io.swagger.v3.oas.models.responses.ApiResponse;
 import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.lang3.BooleanUtils;
 import org.apache.commons.lang3.StringUtils;
@@ -1363,8 +1364,23 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
                 }
                 for (Operation operation : path.readOperations()) {
                     LOGGER.info("Processing operation {}", operation.getOperationId());
-                    if (hasBodyParameter(openAPI, operation) || hasFormParameter(openAPI, operation)) {
-                        String defaultContentType = hasFormParameter(openAPI, operation) ? "application/x-www-form-urlencoded" : "application/json";
+                    boolean hasBodyParameter = hasBodyParameter(openAPI, operation);
+                    boolean hasFormParameter = hasFormParameter(openAPI, operation);
+
+                    // OpenAPI parser do not add Inline One Of models in Operations to Components/Schemas
+                    if (hasBodyParameter) {
+                        Optional.ofNullable(operation.getRequestBody())
+                                .map(RequestBody::getContent)
+                                .ifPresent(this::repairInlineOneOf);
+                    }
+                    if (operation.getResponses() != null) {
+                        operation.getResponses().values().stream().map(ApiResponse::getContent)
+                                .filter(Objects::nonNull)
+                                .forEach(this::repairInlineOneOf);
+                    }
+
+                    if (hasBodyParameter || hasFormParameter) {
+                        String defaultContentType = hasFormParameter ? "application/x-www-form-urlencoded" : "application/json";
                         List<String> consumes = new ArrayList<>(getConsumesInfo(openAPI, operation));
                         String contentType = consumes == null || consumes.isEmpty() ? defaultContentType : consumes.get(0);
                         operation.addExtension("x-contentType", contentType);
@@ -1421,6 +1437,39 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
         }
     }
 
+    /**
+     * Add all OneOf schemas to #/components/schemas and replace them in the original content by ref schema
+     * Replace OneOf with unmodifiable types with an empty Schema
+     *
+     * OpenAPI Parser does not add inline OneOf schemas to models to generate
+     *
+     * @param content a 'content' section in the OAS specification.
+     */
+    private void repairInlineOneOf(final Content content) {
+        content.values().forEach(mediaType -> {
+            final Schema replacingSchema = mediaType.getSchema();
+            if (isOneOfSchema(replacingSchema)) {
+                if (ModelUtils.isSchemaOneOfConsistsOfCustomTypes(openAPI, replacingSchema)) {
+                    final String oneOfModelName = (String) replacingSchema.getExtensions().get("x-one-of-name");
+                    final Schema newRefSchema = new Schema<>().$ref("#/components/schemas/" + oneOfModelName);
+                    mediaType.setSchema(newRefSchema);
+                    ModelUtils.getSchemas(openAPI).put(oneOfModelName, replacingSchema);
+                } else {
+                    mediaType.setSchema(new Schema());
+                }
+            }
+        });
+    }
+
+    private static boolean isOneOfSchema(final Schema schema) {
+        if (schema instanceof ComposedSchema) {
+            ComposedSchema composedSchema = (ComposedSchema) schema;
+            return Optional.ofNullable(composedSchema.getProperties()).map(Map::isEmpty).orElse(true)
+                    && Optional.ofNullable(schema.getExtensions()).map(m -> m.containsKey("x-one-of-name")).orElse(false);
+        }
+        return false;
+    }
+
     private static String getAccept(OpenAPI openAPI, Operation operation) {
         String accepts = null;
         String defaultContentType = "application/json";
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
index aa43075765d0..3555f170faec 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
@@ -129,6 +129,8 @@ public JavaClientCodegen() {
         artifactId = "openapi-java-client";
         apiPackage = "org.openapitools.client.api";
         modelPackage = "org.openapitools.client.model";
+        useOneOfInterfaces = true;
+        addOneOfInterfaceImports = true;
 
         // cliOptions default redefinition need to be updated
         updateOption(CodegenConstants.INVOKER_PACKAGE, this.getInvokerPackage());
@@ -1027,11 +1029,13 @@ public String toApiVarName(String name) {
 
     @Override
     public void addImportsToOneOfInterface(List<Map<String, String>> imports) {
-        for (String i : Arrays.asList("JsonSubTypes", "JsonTypeInfo")) {
-            Map<String, String> oneImport = new HashMap<>();
-            oneImport.put("import", importMapping.get(i));
-            if (!imports.contains(oneImport)) {
-                imports.add(oneImport);
+        if (additionalProperties.containsKey(JACKSON)) {
+            for (String i : Arrays.asList("JsonSubTypes", "JsonTypeInfo")) {
+                Map<String, String> oneImport = new HashMap<>();
+                oneImport.put("import", importMapping.get(i));
+                if (!imports.contains(oneImport)) {
+                    imports.add(oneImport);
+                }
             }
         }
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
index ba5a7f99ef57..83a802c33a25 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
@@ -135,6 +135,8 @@ public SpringCodegen() {
         modelPackage = "org.openapitools.model";
         invokerPackage = "org.openapitools.api";
         artifactId = "openapi-spring";
+        useOneOfInterfaces = true;
+        addOneOfInterfaceImports = true;
 
         // clioOptions default redefinition need to be updated
         updateOption(CodegenConstants.INVOKER_PACKAGE, this.getInvokerPackage());
@@ -868,6 +870,19 @@ public Map<String, Object> postProcessModelsEnum(Map<String, Object> objs) {
         return objs;
     }
 
+    @Override
+    public void addImportsToOneOfInterface(List<Map<String, String>> imports) {
+        if (additionalProperties.containsKey(JACKSON)) {
+            for (String i : Arrays.asList("JsonSubTypes", "JsonTypeInfo")) {
+                Map<String, String> oneImport = new HashMap<>();
+                oneImport.put("import", importMapping.get(i));
+                if (!imports.contains(oneImport)) {
+                    imports.add(oneImport);
+                }
+            }
+        }
+    }
+
     public void setUseBeanValidation(boolean useBeanValidation) {
         this.useBeanValidation = useBeanValidation;
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
index a4bc0147c655..f4943b9b1f67 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
@@ -1652,4 +1652,25 @@ public static SemVer getOpenApiVersion(OpenAPI openAPI, String location, List<Au
 
         return new SemVer(version);
     }
+
+    public static boolean isSchemaOneOfConsistsOfCustomTypes(OpenAPI openAPI, Schema schema) {
+        if (schema instanceof ComposedSchema) {
+            ComposedSchema composedSchema = (ComposedSchema) schema;
+            if (composedSchema.getOneOf() == null || composedSchema.getOneOf().isEmpty()) {
+                return false;
+            }
+            for (Schema oneOfSchema : composedSchema.getOneOf()) {
+                if (oneOfSchema.get$ref() != null) {
+                    oneOfSchema = ModelUtils.getReferencedSchema(openAPI, schema);
+                }
+                if (!(oneOfSchema instanceof ComposedSchema
+                    || oneOfSchema instanceof MapSchema
+                    || oneOfSchema instanceof ArraySchema
+                    || oneOfSchema instanceof ObjectSchema)) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
 }
diff --git a/modules/openapi-generator/src/main/resources/Java/oneof_interface.mustache b/modules/openapi-generator/src/main/resources/Java/oneof_interface.mustache
index 02deb483d5fd..fe696c971606 100644
--- a/modules/openapi-generator/src/main/resources/Java/oneof_interface.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/oneof_interface.mustache
@@ -1,6 +1,6 @@
 {{>additionalModelTypeAnnotations}}{{>generatedAnnotation}}{{>typeInfoAnnotation}}{{>xmlAnnotation}}
 public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}} {
-    {{#discriminator}}
+    {{^vendorExtensions.x-deduction}}{{#discriminator}}
     public {{propertyType}} {{propertyGetter}}();
-    {{/discriminator}}
+    {{/discriminator}}{{/vendorExtensions.x-deduction}}
 }
diff --git a/modules/openapi-generator/src/main/resources/Java/typeInfoAnnotation.mustache b/modules/openapi-generator/src/main/resources/Java/typeInfoAnnotation.mustache
index 63eb42ea5001..2eda38e95cfb 100644
--- a/modules/openapi-generator/src/main/resources/Java/typeInfoAnnotation.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/typeInfoAnnotation.mustache
@@ -1,6 +1,15 @@
 {{#jackson}}
 
+{{^vendorExtensions.x-deduction}}
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "{{{discriminator.propertyBaseName}}}", visible = true)
+{{/vendorExtensions.x-deduction}}{{#vendorExtensions.x-deduction}}
+@JsonTypeInfo(use = JsonTypeInfo.Id.DEDUCTION)
+@JsonSubTypes({
+{{#vendorExtensions.x-deduction-model-names}}
+    @JsonSubTypes.Type(value = {{.}}.class, name = "{{.}}"),
+{{/vendorExtensions.x-deduction-model-names}}
+})
+{{/vendorExtensions.x-deduction}}
 {{#discriminator.mappedModels}}
 {{#-first}}
 @JsonSubTypes({
@@ -13,4 +22,4 @@
 {{#isClassnameSanitized}}
 @JsonTypeName("{{name}}")
 {{/isClassnameSanitized}}
-{{/jackson}}
+{{/jackson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/libraries/spring-boot/oneof_interface.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/libraries/spring-boot/oneof_interface.mustache
new file mode 100644
index 000000000000..fe696c971606
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/libraries/spring-boot/oneof_interface.mustache
@@ -0,0 +1,6 @@
+{{>additionalModelTypeAnnotations}}{{>generatedAnnotation}}{{>typeInfoAnnotation}}{{>xmlAnnotation}}
+public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}} {
+    {{^vendorExtensions.x-deduction}}{{#discriminator}}
+    public {{propertyType}} {{propertyGetter}}();
+    {{/discriminator}}{{/vendorExtensions.x-deduction}}
+}
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/model.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/model.mustache
index 78c3c9ae19d4..8b39ebd13c30 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/model.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/model.mustache
@@ -37,7 +37,7 @@ import org.springframework.hateoas.RepresentationModel;
 {{>enumOuterClass}}
 {{/isEnum}}
 {{^isEnum}}
-{{>pojo}}
+{{#vendorExtensions.x-is-one-of-interface}}{{>oneof_interface}}{{/vendorExtensions.x-is-one-of-interface}}{{^vendorExtensions.x-is-one-of-interface}}{{>pojo}}{{/vendorExtensions.x-is-one-of-interface}}
 {{/isEnum}}
 {{/model}}
 {{/models}}
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/oneof_interface.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/oneof_interface.mustache
new file mode 100644
index 000000000000..fe696c971606
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/oneof_interface.mustache
@@ -0,0 +1,6 @@
+{{>additionalModelTypeAnnotations}}{{>generatedAnnotation}}{{>typeInfoAnnotation}}{{>xmlAnnotation}}
+public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}} {
+    {{^vendorExtensions.x-deduction}}{{#discriminator}}
+    public {{propertyType}} {{propertyGetter}}();
+    {{/discriminator}}{{/vendorExtensions.x-deduction}}
+}
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
index 4226edb1170c..3122414c5982 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
@@ -3,7 +3,7 @@
  */{{#description}}
 @ApiModel(description = "{{{.}}}"){{/description}}
 {{>generatedAnnotation}}{{#discriminator}}{{>typeInfoAnnotation}}{{/discriminator}}{{>xmlAnnotation}}{{>additionalModelTypeAnnotations}}
-public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{^parent}}{{#hateoas}}extends RepresentationModel<{{classname}}> {{/hateoas}}{{/parent}} {{#serializableModel}}implements Serializable{{/serializableModel}} {
+public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{^parent}}{{#hateoas}}extends RepresentationModel<{{classname}}> {{/hateoas}}{{/parent}}{{#vendorExtensions.x-implements}}{{#-first}}implements {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{#-last}} {{/-last}}{{/vendorExtensions.x-implements}}{
 {{#serializableModel}}
   private static final long serialVersionUID = 1L;
 
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/typeInfoAnnotation.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/typeInfoAnnotation.mustache
index 81c2ba05f903..206f1f878898 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/typeInfoAnnotation.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/typeInfoAnnotation.mustache
@@ -1,8 +1,14 @@
 {{#jackson}}
 
+{{^vendorExtensions.x-deduction}}
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "{{{discriminator.propertyBaseName}}}", visible = true)
+{{/vendorExtensions.x-deduction}}{{#vendorExtensions.x-deduction}}
+@JsonTypeInfo(use = JsonTypeInfo.Id.DEDUCTION){{/vendorExtensions.x-deduction}}
 @JsonSubTypes({
   {{#discriminator.mappedModels}}
   @JsonSubTypes.Type(value = {{modelName}}.class, name = "{{^vendorExtensions.x-discriminator-value}}{{mappingName}}{{/vendorExtensions.x-discriminator-value}}{{#vendorExtensions.x-discriminator-value}}{{{vendorExtensions.x-discriminator-value}}}{{/vendorExtensions.x-discriminator-value}}"),
   {{/discriminator.mappedModels}}
-}){{/jackson}}
+  {{#vendorExtensions.x-deduction-model-names}}
+  @JsonSubTypes.Type(value = {{.}}.class, name = "{{.}}"),
+  {{/vendorExtensions.x-deduction-model-names}}
+}){{/jackson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
index 6d74693c21a3..c8ce597df0d4 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
@@ -1137,10 +1137,15 @@ public void testComposedSchemaAllOfDiscriminatorMapLegacy() {
         Assert.assertNull(reptile.discriminator);
 
         // the MyPets discriminator contains Cat and Lizard
+        List<String> myPetsModelNames = Arrays.asList("Cat", "Lizard");
         CodegenDiscriminator myPetDisc = new CodegenDiscriminator();
         myPetDisc.setPropertyName(propertyName);
         myPetDisc.setPropertyBaseName(propertyBaseName);
         hs.clear();
+        for (String myPetsModelName: myPetsModelNames) {
+            hs.add(new CodegenDiscriminator.MappedModel(myPetsModelName, codegen.toModelName(myPetsModelName)));
+        }
+        myPetDisc.setMappedModels(hs);
         modelName = "MyPets";
         sc = openAPI.getComponents().getSchemas().get(modelName);
         CodegenModel myPets = codegen.fromModel(modelName, sc);
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
index f034760ea969..aaa1c0530990 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
@@ -17,8 +17,10 @@
 
 package org.openapitools.codegen.java;
 
+import static org.openapitools.codegen.TestUtils.assertFileContains;
 import static org.openapitools.codegen.TestUtils.validateJavaSourceFiles;
 import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertFalse;
 import static org.testng.Assert.assertTrue;
 
 import java.io.File;
@@ -43,6 +45,7 @@
 import java.util.stream.Collectors;
 
 import org.openapitools.codegen.ClientOptInput;
+import org.openapitools.codegen.CodegenConfig;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenModel;
 import org.openapitools.codegen.CodegenOperation;
@@ -55,7 +58,9 @@
 import org.openapitools.codegen.config.CodegenConfigurator;
 import org.openapitools.codegen.languages.AbstractJavaCodegen;
 import org.openapitools.codegen.languages.JavaClientCodegen;
+import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.Assert;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 import com.google.common.collect.ImmutableMap;
@@ -1222,4 +1227,130 @@ public void testWebClientWithFreeFormInQueryParameters() throws IOException {
         final Path defaultApi = Paths.get(output + "/src/main/java/xyz/abcdef/ApiClient.java");
         TestUtils.assertFileContains(defaultApi, "value instanceof Map");
     }
+
+    @Test(dataProvider = "librariesToSpecificationsCartesianProduct")
+    public void oneOfModelsGeneration(String library, String specificationFile) throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        String outputPath = output.getAbsolutePath().replace('\\', '/');
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/" + specificationFile);
+        final CodegenConfig codegen = new JavaClientCodegen();
+        ((JavaClientCodegen)codegen).setSerializationLibrary(JavaClientCodegen.SERIALIZATION_LIBRARY_JACKSON);
+        codegen.setLibrary(library);
+        codegen.setOpenAPI(openAPI);
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_TESTS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_DOCS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.APIS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.SUPPORTING_FILES, "false");
+
+        generator.opts(input).generate();
+
+        final String responseCode = "200";
+        final String extension = "x-one-of-name";
+        final Operation operation = openAPI.getPaths().get("/addFruits").getPost();
+        List<String> oneOfModels = new ArrayList<>();
+
+        // If response body contains oneOf definition - add OneOf model
+        final ApiResponse apiResponse = operation.getResponses().get(responseCode);
+        final Schema responseSchema = ModelUtils.getSchemaFromResponse(apiResponse);
+        if (ModelUtils.isArraySchema(responseSchema)) {
+            Schema responseItems = ((ArraySchema) responseSchema).getItems();
+            if (responseItems.get$ref() == null) {
+                oneOfModels.add((String) (responseItems.getExtensions().get(extension)));
+            }
+        }
+
+        // If request body contains oneOf definition - add OneOf model
+        final RequestBody requestBody = operation.getRequestBody();
+        final Schema requestSchema = ModelUtils.getSchemaFromRequestBody(requestBody);
+        if (ModelUtils.isArraySchema(requestSchema)) {
+            Schema requestItems = ((ArraySchema) requestSchema).getItems();
+            if (requestItems.get$ref() == null) {
+                oneOfModels.add((String) (requestItems.getExtensions().get(extension)));
+            }
+        }
+
+        List<String> models = new ArrayList<>();
+        // If model contains discriminator - add to OneOf models, otherwise - generic models
+        openAPI.getComponents().getSchemas().forEach((modelName, modelSchema) -> {
+            if (modelSchema.getDiscriminator() != null || (modelSchema.getExtensions() != null && modelSchema.getExtensions().containsKey("x-one-of-name"))) {
+                oneOfModels.add(modelName);
+            } else {
+                // exclude allOf models
+                if (!modelName.contains("_")) {
+                    models.add(modelName);
+                }
+            }
+        });
+        assertFalse(oneOfModels.isEmpty());
+
+        final String pathFormat = "%s/%s/%s.java";
+        final String relativePath = "/src/main/java/org/openapitools/client/model";
+        final String jacksonSubTypeFormat = "@JsonSubTypes.Type(value = %s.class, name = \"%s\"),";
+
+        models.forEach(modelName -> {
+            final String modelPath = String.format(Locale.ROOT, pathFormat, outputPath, relativePath, modelName);
+
+            oneOfModels.forEach(oneOfModelName -> {
+                // Models should implement all linked OneOf interfaces
+                assertFileContains(Paths.get(modelPath), oneOfModelName);
+
+                // OneOf model should contain relevant jackson annotations
+                final String oneOfPath = String.format(Locale.ROOT, pathFormat, outputPath, relativePath, oneOfModelName);
+                assertFileContains(Paths.get(oneOfPath), String.format(Locale.ROOT, jacksonSubTypeFormat, modelName, modelName));
+            });
+        });
+    }
+
+    // Currently, not for NATIVE, JERSEY2, OKHTTP_GSON, MICROPROFILE or RETROFIT2
+    public static Object[][] librariesProviderMethod() {
+        return new Object[][] {
+                { JavaClientCodegen.FEIGN },
+                { JavaClientCodegen.GOOGLE_API_CLIENT },
+                { JavaClientCodegen.JERSEY1 },
+                { JavaClientCodegen.RESTEASY },
+                { JavaClientCodegen.RESTTEMPLATE },
+                { JavaClientCodegen.WEBCLIENT },
+                { JavaClientCodegen.REST_ASSURED },
+                { JavaClientCodegen.VERTX },
+                { JavaClientCodegen.APACHE },
+        };
+    }
+
+    public static Object[][] specificationsProviderMethod() {
+        return new Object[][] {
+                { "oneOf_inherited_class.yaml" },
+                { "oneOf_inherited_class_array.yaml" },
+                { "oneOf_interface.yaml" },
+                { "oneOf_interface_array.yaml" },
+                { "oneOf_with_allOf_inherited_class.yaml" },
+                { "oneOf_with_allOf_inherited_class_array.yaml" },
+        };
+    }
+
+    // Combines each library to each specification case
+    @DataProvider(name = "librariesToSpecificationsCartesianProduct")
+    public static Object[][] librariesToSpecificationsCartesianProduct() {
+        Object[][] librariesProvider = librariesProviderMethod();
+        Object[][] specProvider = specificationsProviderMethod();
+        Object[][] cartesianProduct = new Object[librariesProvider.length * specProvider.length][2];
+        int i = 0;
+        for (Object[] library : librariesProvider) {
+            for (Object[] spec : specProvider) {
+                cartesianProduct[i][0] = library[0];
+                cartesianProduct[i++][1] = spec[0];
+            }
+        }
+        return cartesianProduct;
+    }
 }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
index 66817e5dbc77..56cffd2d1088 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
@@ -21,20 +21,27 @@
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.info.Info;
+import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Schema;
+import io.swagger.v3.oas.models.parameters.RequestBody;
+import io.swagger.v3.oas.models.responses.ApiResponse;
 import io.swagger.v3.oas.models.servers.Server;
 import io.swagger.v3.parser.core.models.ParseOptions;
 import org.openapitools.codegen.*;
 import org.openapitools.codegen.languages.SpringCodegen;
 import org.openapitools.codegen.languages.features.CXFServerFeatures;
+import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.Assert;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.stream.Collectors;
 
@@ -43,6 +50,7 @@
 import static org.openapitools.codegen.TestUtils.assertFileNotContains;
 import static org.openapitools.codegen.languages.SpringCodegen.RESPONSE_WRAPPER;
 import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertFalse;
 
 public class SpringCodegenTest {
 
@@ -723,4 +731,139 @@ public void shouldGenerateDefaultValueForEnumRequestParameter() throws IOExcepti
             "@RequestParam(value = \"testParameter1\", required = false, defaultValue = \"BAR\")",
             "@RequestParam(value = \"TestParameter2\", required = false, defaultValue = \"BAR\")");
     }
+
+    @Test(dataProvider = "specifications")
+    public void oneOfModelsGeneration(String specificationFile) throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        String outputPath = output.getAbsolutePath().replace('\\', '/');
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/" + specificationFile);
+        final CodegenConfig codegen = new SpringCodegen();
+        codegen.setOpenAPI(openAPI);
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_TESTS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_DOCS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.APIS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.SUPPORTING_FILES, "false");
+
+        generator.opts(input).generate();
+
+        final String responseCode = "200";
+        final String extension = "x-one-of-name";
+        final Operation operation = openAPI.getPaths().get("/addFruits").getPost();
+        List<String> oneOfModels = new ArrayList<>();
+
+        // If response body contains oneOf definition - add OneOf model
+        final ApiResponse apiResponse = operation.getResponses().get(responseCode);
+        final Schema responseSchema = ModelUtils.getSchemaFromResponse(apiResponse);
+        if (ModelUtils.isArraySchema(responseSchema)) {
+            Schema responseItems = ((ArraySchema) responseSchema).getItems();
+            if (responseItems.get$ref() == null) {
+                oneOfModels.add((String) (responseItems.getExtensions().get(extension)));
+            }
+        }
+
+        // If request body contains oneOf definition - add OneOf model
+        final RequestBody requestBody = operation.getRequestBody();
+        final Schema requestSchema = ModelUtils.getSchemaFromRequestBody(requestBody);
+        if (ModelUtils.isArraySchema(requestSchema)) {
+            Schema requestItems = ((ArraySchema) requestSchema).getItems();
+            if (requestItems.get$ref() == null) {
+                oneOfModels.add((String) (requestItems.getExtensions().get(extension)));
+            }
+        }
+
+        List<String> models = new ArrayList<>();
+        // If model contains discriminator - add to OneOf models, otherwise - generic models
+        openAPI.getComponents().getSchemas().forEach((modelName, modelSchema) -> {
+            if (modelSchema.getDiscriminator() != null || (modelSchema.getExtensions() != null && modelSchema.getExtensions().containsKey("x-one-of-name"))) {
+                oneOfModels.add(modelName);
+            } else {
+                // exclude allOf models
+                if (!modelName.contains("_")) {
+                    models.add(modelName);
+                }
+            }
+        });
+        assertFalse(oneOfModels.isEmpty());
+
+        final String pathFormat = "%s/%s/%s.java";
+        final String relativePath = "/src/main/java/org/openapitools/model";
+        final String jacksonSubTypeFormat = "@JsonSubTypes.Type(value = %s.class, name = \"%s\"),";
+
+        models.forEach(modelName -> {
+            final String modelPath = String.format(Locale.ROOT, pathFormat, outputPath, relativePath, modelName);
+
+            oneOfModels.forEach(oneOfModelName -> {
+                // Models should implement all linked OneOf interfaces
+                assertFileContains(Paths.get(modelPath), oneOfModelName);
+
+                // OneOf model should contain relevant jackson annotations
+                final String oneOfPath = String.format(Locale.ROOT, pathFormat, outputPath, relativePath, oneOfModelName);
+                assertFileContains(Paths.get(oneOfPath), String.format(Locale.ROOT, jacksonSubTypeFormat, modelName, modelName));
+            });
+        });
+    }
+
+    @Test(dataProvider = "baseClassSpecifications")
+    public void oneOfShouldBeObject(String specificationFile) throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        String outputPath = output.getAbsolutePath().replace('\\', '/');
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/" + specificationFile);
+        final CodegenConfig codegen = new SpringCodegen();
+        codegen.setOpenAPI(openAPI);
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_TESTS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_DOCS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.APIS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.SUPPORTING_FILES, "false");
+
+        generator.opts(input).generate();
+
+        final String pathFormat = "%s/%s/%s.java";
+        final String relativePath = "/src/main/java/org/openapitools/api";
+
+        // OneOf model should be replaced with object
+        final String oneOfPath = String.format(Locale.ROOT, pathFormat, outputPath, relativePath, "AddFruitsApi");
+        assertFileContains(Paths.get(oneOfPath), "ResponseEntity<Object>", "Object body");
+    }
+
+    @DataProvider(name = "specifications")
+    public static Object[][] specificationsProviderMethod() {
+        return new Object[][] {
+                { "oneOf_inherited_class.yaml" },
+                { "oneOf_inherited_class_array.yaml" },
+                { "oneOf_interface.yaml" },
+                { "oneOf_interface_array.yaml" },
+                { "oneOf_with_allOf_inherited_class.yaml" },
+                { "oneOf_with_allOf_inherited_class_array.yaml" },
+        };
+    }
+
+    @DataProvider(name = "baseClassSpecifications")
+    public static Object[][] baseClassSpecificationsProviderMethod() {
+        return new Object[][] {
+                { "oneOf_interface_base_classes.yaml" },
+                { "oneOf_interface_base_classes_combined.yaml" },
+        };
+    }
 }
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class.yaml
new file mode 100644
index 000000000000..e9a4a9360024
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class.yaml
@@ -0,0 +1,46 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "API should have import for OneOf Class, models should extend OneOf Class"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Fruit'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/Fruit'
+components:
+  schemas:
+    Fruit:
+      type: object
+      oneOf:
+        - $ref: '#/components/schemas/Apple'
+        - $ref: '#/components/schemas/Orange'
+      discriminator:
+        propertyName: kind
+    Apple:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier:
+          type: string
+      required:
+        - kind
+    Orange:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier2:
+          type: string
+      required:
+        - kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class_array.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class_array.yaml
new file mode 100644
index 000000000000..6f56d61f530a
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_inherited_class_array.yaml
@@ -0,0 +1,50 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "API should have import for OneOf Class, models should extend OneOf Class"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Fruit'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: array
+              items:
+                $ref: '#/components/schemas/Fruit'
+components:
+  schemas:
+    Fruit:
+      type: object
+      oneOf:
+        - $ref: '#/components/schemas/Apple'
+        - $ref: '#/components/schemas/Orange'
+      discriminator:
+        propertyName: kind
+    Apple:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier:
+          type: string
+      required:
+        - kind
+    Orange:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier2:
+          type: string
+      required:
+        - kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_interface.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface.yaml
new file mode 100644
index 000000000000..93d67198c866
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface.yaml
@@ -0,0 +1,52 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "OneOf interface should be generated, API has link to OneOf, models implement OneOf interface"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                oneOf:
+                  - $ref: '#/components/schemas/Apple'
+                  - $ref: '#/components/schemas/Orange'
+                discriminator:
+                  propertyName: kind
+      requestBody:
+        content:
+          application/json:
+            schema:
+              oneOf:
+                - $ref: '#/components/schemas/Apple'
+                - $ref: '#/components/schemas/Orange'
+components:
+  schemas:
+    Apple:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier:
+          type: string
+      required:
+        - kind
+    Orange:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier2:
+          type: string
+      required:
+        - kind
+    Fruit:
+      type: object
+      oneOf:
+        - $ref: '#/components/schemas/Apple'
+        - $ref: '#/components/schemas/Orange'
+      discriminator:
+        propertyName: kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_array.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_array.yaml
new file mode 100644
index 000000000000..77122d4b576d
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_array.yaml
@@ -0,0 +1,51 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "OneOf interface should be generated, API has link to OneOf, models implement OneOf interface"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  oneOf:
+                    - $ref: '#/components/schemas/Apple'
+                    - $ref: '#/components/schemas/Orange'
+                  discriminator:
+                    propertyName: kind
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: array
+              items:
+                oneOf:
+                  - $ref: '#/components/schemas/Apple'
+                  - $ref: '#/components/schemas/Orange'
+                discriminator:
+                  propertyName: kind
+components:
+  schemas:
+    Apple:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier:
+          type: string
+      required:
+        - kind
+    Orange:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier2:
+          type: string
+      required:
+        - kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes.yaml
new file mode 100644
index 000000000000..3b85c08b91d0
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes.yaml
@@ -0,0 +1,27 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "OneOf interface should be generated, API has link to OneOf, models implement OneOf interface"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                oneOf:
+                  - type: string
+                    format: date
+                  - type: string
+                    format: date-time
+      requestBody:
+        content:
+          application/json:
+            schema:
+              oneOf:
+                - type: string
+                  format: date
+                - type: string
+                  format: date-time
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes_combined.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes_combined.yaml
new file mode 100644
index 000000000000..cae0db1458e4
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_interface_base_classes_combined.yaml
@@ -0,0 +1,36 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "OneOf interface should be generated, API has link to OneOf, models implement OneOf interface"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                oneOf:
+                  - type: string
+                    format: date
+                  - $ref: '#/components/schemas/Apple'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              oneOf:
+                - type: string
+                  format: date
+                - $ref: '#/components/schemas/Apple'
+components:
+  schemas:
+    Apple:
+      type: object
+      properties:
+        kind:
+          type: string
+        identifier:
+          type: string
+      required:
+        - kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class.yaml
new file mode 100644
index 000000000000..76134cd5dd73
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class.yaml
@@ -0,0 +1,46 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "API should have import for OneOf Class, models should extend OneOf Class"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Fruit'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/Fruit'
+components:
+  schemas:
+    Apple:
+      type: object
+      allOf:
+        - $ref: '#/components/schemas/Fruit'
+        - type: object
+          properties:
+            identifier:
+              type: string
+    Orange:
+      type: object
+      allOf:
+        - $ref: '#/components/schemas/Fruit'
+        - type: object
+          properties:
+            identifier2:
+              type: string
+    Fruit:
+      type: object
+      properties:
+        kind:
+          type: string
+      required:
+        - kind
+      discriminator:
+        propertyName: kind
diff --git a/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class_array.yaml b/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class_array.yaml
new file mode 100644
index 000000000000..c067a483714d
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/oneOf_with_allOf_inherited_class_array.yaml
@@ -0,0 +1,50 @@
+openapi: 3.0.0
+info:
+  version: "1.0.0"
+  title: "API should have import for OneOf Class, models should extend OneOf Class"
+paths:
+  /addFruits:
+    post:
+      responses:
+        '200':
+          description: Returns a list of fruits
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Fruit'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: array
+              items:
+                $ref: '#/components/schemas/Fruit'
+components:
+  schemas:
+    Apple:
+      type: object
+      allOf:
+        - $ref: '#/components/schemas/Fruit'
+        - type: object
+          properties:
+            identifier:
+              type: string
+    Orange:
+      type: object
+      allOf:
+        - $ref: '#/components/schemas/Fruit'
+        - type: object
+          properties:
+            identifier2:
+              type: string
+    Fruit:
+      type: object
+      properties:
+        kind:
+          type: string
+      required:
+        - kind
+      discriminator:
+        propertyName: kind