[Java][Spring] fix one of

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) {
@@ -2418,16 +2418,35 @@ 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));
         if (!this.getLegacyDiscriminatorBehavior()) {
             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);

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";

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);
+                }
             }
         }
     }

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;
     }

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;
+    }
 }

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}}
 }

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}}

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}}
+}

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}}

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}}
+}

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;
 

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}}

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);