fix(java-spring): expose requestBody named examples to Mustache template context (#23607)

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

@@ -2454,6 +2454,23 @@ public void setParameterExamples(CodegenParameter codegenParameter, Parameter pa
         }
     }
 
+    /**
+     * Return the examples of the request body parameter.
+     *
+     * @param codegenParameter Codegen parameter
+     * @param requestBody      Request body
+     */
+    public void setParameterExamples(CodegenParameter codegenParameter, RequestBody requestBody) {
+        if (requestBody.getContent() != null && !requestBody.getContent().isEmpty()) {
+            for (MediaType mediaType : requestBody.getContent().values()) {
+                if (mediaType.getExamples() != null && !mediaType.getExamples().isEmpty()) {
+                    codegenParameter.examples = mediaType.getExamples();
+                    break;
+                }
+            }
+        }
+    }
+
     /**
      * Return the example value of the parameter.
      *
@@ -2463,6 +2480,9 @@ public void setParameterExamples(CodegenParameter codegenParameter, Parameter pa
     public void setParameterExampleValue(CodegenParameter codegenParameter, RequestBody requestBody) {
         Content content = requestBody.getContent();
 
+        // Reuse the helper method to correctly catch examples across all media types
+        setParameterExamples(codegenParameter, requestBody);
+
         Optional<Object> contentExample = ExamplesUtils.getContentExample(content);
 
         if (contentExample.isPresent()) {
@@ -8290,6 +8310,9 @@ public CodegenParameter fromRequestBody(RequestBody body, Set<String> imports, S
             codegenParameter.vendorExtensions.putAll(body.getExtensions());
         }
 
+        // Ensure request body named examples are populated globally for ALL generators
+        setParameterExamples(codegenParameter, body);
+
         String name = null;
         LOGGER.debug("Request body = {}", body);
         Schema schema = ModelUtils.getSchemaFromRequestBody(body);
@@ -8417,11 +8440,6 @@ public CodegenParameter fromRequestBody(RequestBody body, Set<String> imports, S
             if (original.getMinimum() != null) {
                 codegenParameter.setMinimum(String.valueOf(original.getMinimum().doubleValue()));
             }
-            /* comment out below as we don't store `title` in the codegen parametera the moment
-            if (original.getTitle() != null) {
-                codegenParameter.setTitle(original.getTitle());
-            }
-             */
         }
 
         return codegenParameter;

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

@@ -1751,30 +1751,7 @@ public void setParameterExampleValue(CodegenParameter codegenParameter, Paramete
 
         setParameterExampleValue(codegenParameter);
     }
-
-    /**
-     * Return the example value of the parameter. Overrides the parent method in DefaultCodegen
-     * to not set examples on complex models, as they don't compile properly.
-     *
-     * @param codegenParameter Codegen parameter
-     * @param requestBody      Request body
-     */
-    @Override
-    public void setParameterExampleValue(CodegenParameter codegenParameter, RequestBody requestBody) {
-        boolean isModel = (codegenParameter.isModel || (codegenParameter.isContainer && codegenParameter.getItems().isModel));
-
-        MediaType mediaType = requestBody.getContent().values().iterator().next();
-        boolean hasExample = mediaType.getExample() != null || (mediaType.getExamples() != null && !mediaType.getExamples().isEmpty());
-        if (isModel) {
-            if (hasExample) {
-                once(LOGGER).warn("Ignoring complex example on request body");
-            }
-            setParameterExampleValue(codegenParameter);
-        } else {
-            super.setParameterExampleValue(codegenParameter, requestBody);
-        }
-    }
-
+
     @Override
     public void setParameterExampleValue(CodegenParameter p) {
         String example;

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

@@ -8690,4 +8690,29 @@ public void testReactiveSpringHttpInterfaceSupportListOfStringReturnTypeNoRespon
                 "Mono<Set<String>> getUserIdSet"
         );
     }
+
+    @Test
+    public void shouldExposeRequestBodyNamedExamplesToTemplateContext_issue23607() throws IOException {
+        OpenAPI openAPI = new OpenAPIParser().readLocation(
+                "src/test/resources/3_0/spring/requestbody_named_examples.yaml",
+                null,
+                new ParseOptions()
+        ).getOpenAPI();
+
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.additionalProperties().put(INTERFACE_ONLY, "true");
+
+        // Preprocess and set OpenAPI to mirror DefaultGenerator behavior
+        codegen.preprocessOpenAPI(openAPI);
+        codegen.setOpenAPI(openAPI);
+
+        // Verify via codegen operation inspection after initialization
+        Operation operation = openAPI.getPaths().get("/users").getPost();
+        CodegenOperation codegenOperation = codegen.fromOperation("/users", "POST", operation, null);
+
+        assertNotNull(codegenOperation.bodyParam);
+        assertNotNull(codegenOperation.bodyParam.examples);
+        assertTrue(codegenOperation.bodyParam.examples.containsKey("Jessica"));
+        assertTrue(codegenOperation.bodyParam.examples.containsKey("Ron"));
+    }
 }

modules/openapi-generator/src/test/resources/3_0/spring/requestbody_named_examples.yaml

@@ -0,0 +1,36 @@
+openapi: 3.0.0
+info:
+  title: Example API
+  version: 1.0.0
+paths:
+  /users:
+    post:
+      summary: Adds a new user
+      tags:
+        - User
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/User"
+            examples:
+              Jessica:
+                value:
+                  id: 10
+                  name: Jessica Smith
+              Ron:
+                value:
+                  id: 11
+                  name: Ron Stewart
+      responses:
+        "200":
+          description: OK
+components:
+  schemas:
+    User:
+      type: object
+      properties:
+        id:
+          type: integer
+        name:
+          type: string