Spring Boot RestController inheritance and ambiguous mapping issue

Question

I'm trying to implement inherited controllers for my Spring Boot Rest project. As you see in example code snippets, I have standard endpoints for all controllers at BaseTableController, but for some of the concrete controllers I need to override methods. When I implement it like that I get Ambiguous mapping. Cannot map 'clientRfmController' method Ambiguous mapping. Cannot map 'clientRfmController' method exception on startup.

public abstract class BaseTableController<T extends BaseTableModel> {  

@Override
    public BaseTableService<T> getService() {
        return (BaseTableService<T>) super.getService();
    }
   @GetMapping({
            PATH_GET,
            PATH_VIEW_GET}
    )
    public T getWithParam(@RequestParam UUID gid) {
        T t = null;
        if (gid != null) {
            t = getService().get(gid);
        }
        return getWithErrorCheck(t);
    }
}

-

@RestController
@RequestMapping(TBL_CLIENTRFM)
public class ClientRfmController extends BaseTableController<ClientRfmCommon> {
    @Override
    public ClientRfmService getService() {
        return (ClientRfmService) super.getService();
    }

    @GetMapping(value = {PATH_GET, PATH_VIEW_GET})
    public List<ClientRfmCommon> getByAccid(Long accid, @RequestParam(required = false) UUID gid) {
        List<ClientRfmCommon> byAccid = null;
        if (gid != null) {
            byAccid = Collections.singletonList(super.getWithParam(gid));
        } else {
            byAccid = Collections.singletonList(getService().getByAccid(accid));
        }
        return byAccid;
    }


}

I've found a workaround by implementing custom RequestMappingHandlerMapping.

  @Configuration
    public class WebMvcRegistrationsConfig implements WebMvcRegistrations {

        @Override
        public OoRequestMappingHandlerMapping getRequestMappingHandlerMapping() {
            OoRequestMappingHandlerMapping ooRequestMappingHandlerMapping = new OoRequestMappingHandlerMapping();
            ooRequestMappingHandlerMapping.setOrder(0);
            return ooRequestMappingHandlerMapping;
        }


    }

-

public class OoRequestMappingHandlerMapping extends RequestMappingHandlerMapping {

    @Override
    protected void registerHandlerMethod(Object handler, Method method, RequestMappingInfo mapping) {
        HandlerMethod existingHandlerMethod = getHandlerMethods().get(mapping);
        if (existingHandlerMethod != null) {
            HandlerMethod handlerMethod = createHandlerMethod(handler, method);
            if (handlerMethod.getMethod().getDeclaringClass().isAssignableFrom(existingHandlerMethod.getMethod().getDeclaringClass())) {
                logger.warn(handlerMethod.getBeanType().getSimpleName() + " type (" + handlerMethod.getMethod().getDeclaringClass().getSimpleName() + "->" + handlerMethod.getMethod().getName() +
                        ") registration omitted to avoid ambigious mapping (" + existingHandlerMethod.getMethod().getDeclaringClass().getSimpleName() + "->" + existingHandlerMethod.getMethod().getName() + ")");
                return;
            }
            unregisterMapping(mapping);
        }
        super.registerHandlerMethod(handler, method, mapping);
    }

}

1. Is this correct way to handle this?
2. When I add @EnableWebMvc annotation, this becomes useless. Is there any more generic solution?

Answer 1

  @GetMapping({
            PATH_GET,
            PATH_VIEW_GET}
    ) 

is being repeated in both the parent and child class so you are facing the Ambiguous mapping. please change the path for one.