Resolve vendor extensions on schemas referenced in parameters.

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

@@ -5349,9 +5349,6 @@ public CodegenParameter fromParameter(Parameter parameter, Set<String> imports)
         if (parameter.getExtensions() != null && !parameter.getExtensions().isEmpty()) {
             codegenParameter.vendorExtensions.putAll(parameter.getExtensions());
         }
-        if (parameter.getSchema() != null && parameter.getSchema().getExtensions() != null && !parameter.getSchema().getExtensions().isEmpty()) {
-            codegenParameter.vendorExtensions.putAll(parameter.getSchema().getExtensions());
-        }
 
         Schema parameterSchema;
 
@@ -5386,6 +5383,10 @@ public CodegenParameter fromParameter(Parameter parameter, Set<String> imports)
             parameterSchema = null;
         }
 
+        if (parameterSchema != null && parameterSchema.getExtensions() != null && !parameterSchema.getExtensions().isEmpty()) {
+            codegenParameter.vendorExtensions.putAll(parameterSchema.getExtensions());
+        }
+
         if (parameter instanceof QueryParameter || "query".equalsIgnoreCase(parameter.getIn())) {
             codegenParameter.isQueryParam = true;
             codegenParameter.isAllowEmptyValue = parameter.getAllowEmptyValue() != null && parameter.getAllowEmptyValue();

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

@@ -6175,4 +6175,52 @@ public void annotationLibraryDoesNotCauseImportConflictsInSpringWithAnnotationLi
             "import io.swagger.v3.oas.annotations.media.Schema;"
         );
     }
+
+    @Test
+    public void testExtensionsOnSchema_issue9183() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/issue_9138_resolve_extensions_on_schema.yaml");
+        final SpringCodegen codegen = new SpringCodegen();
+        codegen.setOpenAPI(openAPI);
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        codegen.additionalProperties().put(SpringCodegen.DATE_LIBRARY, "java8-localdatetime");
+        codegen.additionalProperties().put(INTERFACE_ONLY, "true");
+        codegen.additionalProperties().put(USE_RESPONSE_ENTITY, "false");
+        codegen.additionalProperties().put(DELEGATE_PATTERN, "true");
+        codegen.additionalProperties().put(USE_BEANVALIDATION, "true");
+        codegen.additionalProperties().put(PERFORM_BEANVALIDATION, "true");
+        codegen.additionalProperties().put(REQUEST_MAPPING_OPTION, "api_interface");
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.setGenerateMetadata(false); // skip metadata generation
+
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        JavaFileAssert javaFileAssert = JavaFileAssert.assertThat(files.get("TestApi.java"));
+        javaFileAssert
+                .assertMethod("_postToTest")
+                .assertParameter("groupObj")
+                .assertParameterAnnotations()
+                .containsWithNameAndAttributes("Pattern", ImmutableMap.of(
+                        "regexp", "\"[a-zA-Z]\"",
+                        "message", "\"Only letters\""
+                                                                         ))
+                .toParameter()
+                .toMethod()
+                .assertParameter("token")
+                .assertParameterAnnotations()
+                .containsWithNameAndAttributes("Pattern", ImmutableMap.of(
+                        "regexp", "\"[0-9a-fA-F]\"",
+                        "message", "\"Only numbers and letters a-f\""
+                                                                         ));
+    }
+
 }

modules/openapi-generator/src/test/resources/3_0/issue_9138_resolve_extensions_on_schema.yaml

@@ -0,0 +1,32 @@
+openapi: 3.0.3
+info:
+  title: sample spec
+  version: 1.0.0
+paths:
+  /test/{groupObj}:
+    post:
+      summary: Post to test
+      description: ''
+      operationId: postToTest
+      parameters:
+        - in: path
+          name: groupObj
+          required: true
+          schema:
+            $ref: '#/components/schemas/OnlyLetters'
+        - in: query
+          name: token
+          required: true
+          schema:
+            type: string
+            pattern: "[0-9a-fA-F]"
+            x-pattern-message: "Only numbers and letters a-f"
+      responses:
+        201:
+          description: success
+components:
+  schemas:
+    OnlyLetters:
+      type: string
+      pattern: "[a-zA-Z]"
+      x-pattern-message: "Only letters"