[JAVA] Add vendorExtensions.x-class-extra-annotation to oneOf interfaces

modules/openapi-generator/src/main/resources/Java/oneof_interface.mustache

@@ -1,4 +1,7 @@
 {{>additionalOneOfTypeAnnotations}}{{>generatedAnnotation}}{{>typeInfoAnnotation}}{{>xmlAnnotation}}
+{{#vendorExtensions.x-class-extra-annotation}}
+{{{vendorExtensions.x-class-extra-annotation}}}
+{{/vendorExtensions.x-class-extra-annotation}}
 public {{>sealed}}interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}}{{>permits}}{
     {{#discriminator}}
     public {{propertyType}} {{propertyGetter}}();

modules/openapi-generator/src/main/resources/JavaSpring/oneof_interface.mustache

@@ -13,7 +13,8 @@
     @JsonSubTypes.Type(value = {{classname}}.class){{^-last}}, {{/-last}}
     {{/interfaceModels}}
 })
-{{/useDeductionForOneOfInterfaces}}
+{{/useDeductionForOneOfInterfaces}}{{#vendorExtensions.x-class-extra-annotation}}{{{vendorExtensions.x-class-extra-annotation}}}
+{{/vendorExtensions.x-class-extra-annotation}}
 {{/discriminator}}
 {{>generatedAnnotation}}
 

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

@@ -3982,4 +3982,21 @@ public void oneOfWithInnerModelTest() {
         }
         assertTrue(speciesSeen);
     }
+
+    @Test
+    public void testOneOfClassWithAnnotation() throws IOException {
+        final Map<String, File> files = generateFromContract("src/test/resources/3_0/java/oneOf-with-annotations.yaml", RESTCLIENT);
+        JavaFileAssert.assertThat(files.get("Fruit.java"))
+                .isNormalClass()
+                .assertTypeAnnotations().containsWithName("SuppressWarnings");
+    }
+
+    @Test
+    public void testOneOfInterfaceWithAnnotation() throws IOException {
+        final Map<String, File> files = generateFromContract("src/test/resources/3_0/java/oneOf-with-annotations.yaml", RESTCLIENT,
+                Map.of(USE_ONE_OF_INTERFACES, "true"));
+        JavaFileAssert.assertThat(files.get("Fruit.java"))
+                .isInterface()
+                .assertTypeAnnotations().containsWithName("SuppressWarnings");
+    }
 }

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

@@ -5730,4 +5730,12 @@ public void testHasRestControllerDoesNotHaveController_issue21156() throws IOExc
         javaFileAssert
                 .hasImports("java.util.concurrent.atomic.AtomicInteger");
     }
+
+    @Test
+    public void testOneOfInterfaceWithAnnotation() throws IOException {
+        final Map<String, File> files = generateFromContract("src/test/resources/3_0/java/oneOf-with-annotations.yaml", SPRING_BOOT);
+        JavaFileAssert.assertThat(files.get("Fruit.java"))
+                .isInterface()
+                .assertTypeAnnotations().containsWithName("SuppressWarnings");
+    }
 }

modules/openapi-generator/src/test/resources/3_0/java/oneOf-with-annotations.yaml

@@ -0,0 +1,44 @@
+openapi: 3.0.1
+info:
+   title: fruity
+   version: 0.0.1
+paths:
+   /:
+      get:
+         responses:
+            '200':
+               description: desc
+               content:
+                  application/json:
+                     schema:
+                        $ref: '#/components/schemas/fruit'
+components:
+   schemas:
+      fruit:
+         title: fruit
+         x-class-extra-annotation: '@SuppressWarnings("unchecked")'
+         properties:
+            color:
+               type: string
+         oneOf:
+            - $ref: '#/components/schemas/apple'
+            - $ref: '#/components/schemas/banana'
+            - $ref: '#/components/schemas/orange'
+      apple:
+         title: apple
+         type: object
+         properties:
+            kind:
+               type: string
+      banana:
+         title: banana
+         type: object
+         properties:
+            count:
+               type: number
+      orange:
+         title: orange
+         type: object
+         properties:
+            sweet:
+               type: boolean