quarkusio/quarkus · error · IllegalArgumentException

Usage of multiple methods using '@RequestMapping' is not all

Error message

Usage of multiple methods using '@RequestMapping' is not allowed. Offending method is '<class>#<method>'

What it means

In the RESTEasy Reactive Spring Web extension, @RequestMapping is translated to a concrete JAX-RS HTTP verb annotation (@Get, @Post, ...). Spring allows @RequestMapping to list several methods (e.g. {GET, POST}), but the Quarkus translation produces exactly one annotation, so an array with more than one HTTP method is rejected at build time.

Source

Thrown at extensions/spring-web/resteasy-reactive/deployment/src/main/java/io/quarkus/spring/web/resteasy/reactive/deployment/SpringWebResteasyReactiveProcessor.java:239

                if (target.kind() != AnnotationTarget.Kind.METHOD) {
                    return;
                }
                MethodInfo methodInfo = target.asMethod();
                Transformation transform = transformationContext.transform();
                DotName jaxRSMethodAnnotation = null;
                String path = null;
                String[] produces = null;
                String[] consumes = null;

                AnnotationInstance mappingAnnotationInstance = methodInfo.annotation(REQUEST_MAPPING);
                if (mappingAnnotationInstance != null) {
                    AnnotationValue methodValue = mappingAnnotationInstance.value("method");
                    if (methodValue == null) {
                        jaxRSMethodAnnotation = ResteasyReactiveDotNames.GET;
                    } else {
                        String[] methods = methodValue.asEnumArray();
                        if (methods.length > 1) {
                            throw new IllegalArgumentException(
                                    "Usage of multiple methods using '@RequestMapping' is not allowed. Offending method is '"
                                            + methodInfo.declaringClass().name() + "#" + methodInfo.name() + "'");
                        }
                        DotName methodDotName = ResteasyReactiveScanner.METHOD_TO_BUILTIN_HTTP_ANNOTATIONS.get(methods[0]);
                        if (methodDotName == null) {
                            throw new IllegalArgumentException(
                                    "Unsupported HTTP method '" + methods[0] + "' for @RequestMapping. Offending method is '"
                                            + methodInfo.declaringClass().name() + "#" + methodInfo.name() + "'");
                        }
                        jaxRSMethodAnnotation = methodDotName;
                    }
                } else {
                    if (methodInfo.hasAnnotation(GET_MAPPING)) {
                        jaxRSMethodAnnotation = ResteasyReactiveDotNames.GET;
                        mappingAnnotationInstance = methodInfo.annotation(GET_MAPPING);
                    } else if (methodInfo.hasAnnotation(POST_MAPPING)) {
                        jaxRSMethodAnnotation = ResteasyReactiveDotNames.POST;
                        mappingAnnotationInstance = methodInfo.annotation(POST_MAPPING);

View on GitHub (pinned to e1c734241f)

Solutions

1. Split the endpoint into separate methods, one per HTTP verb, each with a single-element @RequestMapping (or @GetMapping/@PostMapping).
2. Use @GetMapping/@PostMapping shortcuts which carry exactly one verb.
3. If both verbs truly share logic, extract the shared body into a common method the two endpoint methods call.

Example fix

// before
@RequestMapping(method = {RequestMethod.GET, RequestMethod.POST}, value = "/items")
public List<Item> items() { ... }

// after
@GetMapping("/items")
public List<Item> getItems() { ... }
@PostMapping("/items")
public List<Item> postItems() { ... }

// ensure single-element method arrays:
// @RequestMapping(value="/x", method=RequestMethod.GET) // OK
// @RequestMapping(value="/x", method={GET, POST}) // NOT allowed

When it happens

Trigger: Annotating a resource method with @RequestMapping(method = {RequestMethod.GET, RequestMethod.POST}) or any multi-element method array.

Common situations: Direct ports of Spring controllers that intentionally accepted multiple verbs on one endpoint.

Related errors

• Unsupported HTTP method '<method>' for @RequestMapping. Offe
• The combination of '@${annotationName}' and '@ServerRequestF
• The combination of '@${annotationName}' and '@ServerExceptio
• Parameter type <type> is being used multiple times in method
• Parameter type <type> is not supported for method<method> of

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/7bd27d49089184ec. Report an issue: GitHub.