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

Author: anupamchaubey

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

@@ -1782,6 +1782,9 @@ public void setParameterExampleValue(CodegenParameter codegenParameter, RequestB
         }
 
         if (mediaType.getExamples() != null && !mediaType.getExamples().isEmpty()) {
+            // FIX for #23607: Assign all named examples to the parameter so Mustache templates can access them
+            codegenParameter.examples = mediaType.getExamples();
+
             Example example = mediaType.getExamples().values().iterator().next();
             if (example.getValue() != null) {
                 if (isModel) {

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

@@ -8690,4 +8690,38 @@ public void testReactiveSpringHttpInterfaceSupportListOfStringReturnTypeNoRespon
                 "Mono<Set<String>> getUserIdSet"
         );
     }
+
+    @Test
+    public void shouldExposeRequestBodyNamedExamplesToTemplateContext_issue23607() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        OpenAPI openAPI = new OpenAPIParser().readLocation(
+                "src/test/resources/3_0/spring/requestbody_named_examples.yaml",
+                null,
+                new ParseOptions()
+        ).getOpenAPI();
+
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(INTERFACE_ONLY, "true");
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.setGeneratorPropertyDefault(CodegenConstants.APIS, "true");
+        generator.setGenerateMetadata(false);
+        generator.opts(input).generate();
+
+        // 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