Fix 3.1 generation for composed schema's with type object (#18002)

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

@@ -7526,7 +7526,7 @@ public class DefaultCodegen implements CodegenConfig {
             }
             // set nullable
             setParameterNullable(codegenParameter, codegenProperty);
-        } else if (ModelUtils.isObjectSchema(schema)) {
+        } else if (ModelUtils.isObjectSchema(schema) || ModelUtils.isComposedSchema(schema)) {
             // object type schema or composed schema with properties defined
             this.addBodyModelSchema(codegenParameter, name, schema, imports, bodyParameterName, false);
         }

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -794,6 +794,35 @@ public class JavaClientCodegenTest {
         files.forEach(File::deleteOnExit);
     }
 
+    @Test
+    public void testTypedAndNonTypedComposedSchemaGeneration_3_1() throws IOException {
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+            .setGeneratorName("java")
+            .setLibrary(JavaClientCodegen.RESTEASY)
+            .setValidateSpec(false)
+            .setInputSpec("src/test/resources/3_1/composed-schemas-with-and-without-type.yaml")
+            .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+
+        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.setGenerateMetadata(false);
+        List<File> files = generator.opts(clientOptInput).generate();
+
+        validateJavaSourceFiles(files);
+
+        Assert.assertEquals(files.size(), 9);
+        files.forEach(File::deleteOnExit);
+    }
+
     @Test
     public void testMultiPartSpecifiesFileName_Issue17367() throws IOException {
         File output = Files.createTempDirectory("test").toFile();

modules/openapi-generator/src/test/resources/3_1/composed-schemas-with-and-without-type.yaml

@@ -0,0 +1,83 @@
+openapi: 3.1.0
+info:
+  version: 1.0.0
+  title: Example
+  license:
+    name: MIT
+servers:
+  - url: http://api.example.xyz/v1
+paths:
+  /pets:
+    patch:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              oneOf:
+                - $ref: '#/components/schemas/Cat'
+                - $ref: '#/components/schemas/Dog'
+                - description: Any kind of pet
+              discriminator:
+                propertyName: pet_type
+      responses:
+        '200':
+          description: Updated
+  /pets-filtered:
+    patch:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              anyOf:
+                - $ref: '#/components/schemas/PetByAge'
+                - $ref: '#/components/schemas/PetByType'
+                - description: Any kind of filter
+      responses:
+        '200':
+          description: Updated
+components:
+  schemas:
+    Pet:
+      type: object
+      required:
+        - pet_type
+    Dog:
+      allOf:
+        - description: Dog information
+        - $ref: '#/components/schemas/Pet'
+        - type: object
+          properties:
+            bark:
+              type: boolean
+            breed:
+              type: string
+              enum: [Dingo, Husky, Retriever, Shepherd]
+    Cat:
+      allOf:
+        - $ref: '#/components/schemas/Pet'
+        - type: object
+          properties:
+            hunts:
+              type: boolean
+            age:
+              type: integer
+    PetByAge:
+      type: object
+      properties:
+        age:
+          type: integer
+        nickname:
+          type: string
+      required:
+        - age
+    PetByType:
+      type: object
+      properties:
+        pet_type:
+          type: string
+          enum: [Cat, Dog]
+        hunts:
+          type: boolean
+      required:
+        - pet_type