code: private boolean checkActionMethod(AppController controller, String actionMethod) {
          HttpMethod method = HttpMethod.getMethod(RequestContext.getHttpRequest());
          if (!controller.actionSupportsHttpMethod(actionMethod, method)) {
              DirectResponse res = new DirectResponse("");
              //see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
              res.setStatus(405);
              LOGGER.warn("Requested action does not support HTTP method: " + method.name() + ", returning status code 405.");
              RequestContext.setControllerResponse(res);
  
              //TODO: candidate for caching below, list of allowed HTTP methods
              //see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
              RequestContext.getHttpResponse().setHeader("Allow", join(controller.allowedActions(actionMethod), ", "));
              return false;
          }
          return true;
      }
docs: Checks if the action method supports requested HTTP method