RequestHandlerObserver.java

/***
 * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * 	http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package br.com.caelum.vraptor.observer;

import static org.slf4j.LoggerFactory.getLogger;

import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.event.Event;
import javax.enterprise.event.Observes;
import javax.inject.Inject;

import org.slf4j.Logger;

import br.com.caelum.vraptor.controller.ControllerMethod;
import br.com.caelum.vraptor.controller.ControllerNotFoundHandler;
import br.com.caelum.vraptor.controller.InvalidInputException;
import br.com.caelum.vraptor.controller.InvalidInputHandler;
import br.com.caelum.vraptor.controller.MethodNotAllowedHandler;
import br.com.caelum.vraptor.core.InterceptorStack;
import br.com.caelum.vraptor.events.ControllerFound;
import br.com.caelum.vraptor.events.RequestSucceded;
import br.com.caelum.vraptor.events.VRaptorRequestStarted;
import br.com.caelum.vraptor.http.MutableRequest;
import br.com.caelum.vraptor.http.MutableResponse;
import br.com.caelum.vraptor.http.UrlToControllerTranslator;
import br.com.caelum.vraptor.http.route.ControllerNotFoundException;
import br.com.caelum.vraptor.http.route.MethodNotAllowedException;

/**
 * Looks up the {@link ControllerMethod} for a specific request and start {@link
 * InterceptorStack} if it was found, otherwise delegates for the 404 component.
 *
 * @author Guilherme Silveira
 * @author Cecilia Fernandes
 * @author Rodrigo Turini
 */
@ApplicationScoped
public class RequestHandlerObserver {

	private static final Logger LOGGER = getLogger(RequestHandlerObserver.class);

	private final UrlToControllerTranslator translator;
	private final ControllerNotFoundHandler controllerNotFoundHandler;
	private final MethodNotAllowedHandler methodNotAllowedHandler;
	private final Event<ControllerFound> controllerFoundEvent;
	private final InterceptorStack interceptorStack;
	private final Event<RequestSucceded> endRequestEvent;
	private final InvalidInputHandler invalidInputHandler;

	/**
	 * @deprecated CDI eyes only
	 */
	protected RequestHandlerObserver() {
		this(null, null, null, null, null, null, null);
	}

	@Inject
	public RequestHandlerObserver(UrlToControllerTranslator translator,
			ControllerNotFoundHandler controllerNotFoundHandler, MethodNotAllowedHandler methodNotAllowedHandler,
			Event<ControllerFound> controllerFoundEvent, Event<RequestSucceded> endRequestEvent,
			InterceptorStack interceptorStack, InvalidInputHandler invalidInputHandler) {
		
		this.translator = translator;
		this.methodNotAllowedHandler = methodNotAllowedHandler;
		this.controllerNotFoundHandler = controllerNotFoundHandler;
		this.controllerFoundEvent = controllerFoundEvent;
		this.endRequestEvent = endRequestEvent;
		this.interceptorStack = interceptorStack;
		this.invalidInputHandler = invalidInputHandler;
	}

	public void handle(@Observes VRaptorRequestStarted event) {
		MutableResponse response = event.getResponse();
		MutableRequest request = event.getRequest();
		try {
			ControllerMethod method = translator.translate(request);
			controllerFoundEvent.fire(new ControllerFound(method));
			interceptorStack.start();
			endRequestEvent.fire(new RequestSucceded(request, response));
		} catch (ControllerNotFoundException e) {
			LOGGER.debug("Could not found controller method", e);
			controllerNotFoundHandler.couldntFind(event.getChain(), request, response);
		} catch (MethodNotAllowedException e) {
			LOGGER.debug("Method is not allowed", e);
			methodNotAllowedHandler.deny(request, response, e.getAllowedMethods());
		} catch (InvalidInputException e) {
			LOGGER.debug("Invalid input", e);
			invalidInputHandler.deny(e);
		}
	}
}