org.atmosphere.samples.pubsub.PubSubController.java Source code

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Here is the source code for org.atmosphere.samples.pubsub.PubSubController.java

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/*
 * Copyright 2014 Jeanfrancois Arcand
 *
 * 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 org.atmosphere.samples.pubsub;

import java.io.IOException;

import javax.servlet.http.HttpServletRequest;

import org.atmosphere.cpr.ApplicationConfig;
import org.atmosphere.cpr.AtmosphereConfig;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResourceEventListenerAdapter;
import org.atmosphere.cpr.Broadcaster;
import org.atmosphere.cpr.BroadcasterFactory;
import org.atmosphere.cpr.ClusterBroadcastFilter;
import org.atmosphere.cpr.HeaderConfig;
import org.atmosphere.plugin.jgroups.JGroupsFilter;
import org.atmosphere.util.XSSHtmlFilter;
import org.atmosphere.websocket.WebSocketEventListenerAdapter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.HandlerMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("/")
public class PubSubController {

    private static final String JGROUPS_PROTOCOL_STACK = "tcp_custom.xml";
    private static final int FORE_EVER = -1;
    private static final String SLASH = "/";

    public PubSubController() {

    }

    /**
     * This method takes a request to subscribe to the topic
     * 
     * @param request
     * @return ModelAndView
     */
    @RequestMapping(value = "/{topic}/**", method = RequestMethod.GET)
    public ModelAndView subscribe(@PathVariable("topic") String topic, HttpServletRequest request,
            AtmosphereResource resource) {

        this.processGet(topic, request, resource);

        // A NoOpView is returned to tell Spring Dispatcher framework not to render anything
        // since it is all Atmosphere-related code
        ModelAndView mv = new ModelAndView(NoOpView.DEFAULT);
        return mv;
    }

    /**
     * Takes a request to post data and broadcasts it to everyone else.
     * 
     * @param request
     * @return String
     */
    @RequestMapping(value = "/{topic}/**", method = RequestMethod.POST)
    public ModelAndView broadcastMessage(@PathVariable("topic") String topic, HttpServletRequest request,
            AtmosphereResource resource) throws Exception {

        this.processPost(topic, request, resource);

        // A NoOpView is returned to tell Spring Dispatcher framework not to render anything
        // since it is all Atmosphere-related code
        ModelAndView mv = new ModelAndView(NoOpView.DEFAULT);
        return mv;
    }

    // See AtmosphereHandlerPubSub example - same code as GET
    private void processGet(String topic, HttpServletRequest req, AtmosphereResource event) {

        event.addEventListener(new WebSocketEventListenerAdapter());
        event.addEventListener(new AtmosphereResourceEventListenerAdapter());

        String restOfTheUrl = (String) req.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);

        Broadcaster b = lookupBroadcaster(topic, restOfTheUrl);

        String header = req.getHeader(HeaderConfig.X_ATMOSPHERE_TRANSPORT);
        if (HeaderConfig.LONG_POLLING_TRANSPORT.equalsIgnoreCase(header)) {
            req.setAttribute(ApplicationConfig.RESUME_ON_BROADCAST, Boolean.TRUE);
        }

        event.suspend(FORE_EVER);
        b.addAtmosphereResource(event);

        ClusterBroadcastFilter filter = newFilter(b, event.getAtmosphereConfig());
        b.getBroadcasterConfig().addFilter(filter);
        b.getBroadcasterConfig().addFilter(new XSSHtmlFilter());
    }

    private ClusterBroadcastFilter newFilter(Broadcaster bc, AtmosphereConfig atmosphereConfig) {
        System.setProperty("java.net.preferIPv4Stack", "true");
        ClusterBroadcastFilter filter = new JGroupsFilter(bc, JGROUPS_PROTOCOL_STACK);
        return filter;
    }

    private void processPost(String topic, HttpServletRequest req, AtmosphereResource resource) throws IOException {

        String restOfTheUrl = (String) req.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);

        Broadcaster b = lookupBroadcaster(topic, restOfTheUrl);

        String message = req.getReader().readLine();
        resource.resume();
        if (message != null && message.indexOf("message") != FORE_EVER) {
            b.broadcast(message.substring("message=".length()));
        }
    }

    /**
     * Retrieve the {@link Broadcaster} based on the request's path info.
     * 
     * @param pathInfo
     * @return the {@link Broadcaster} based on the request's path info.
     */
    Broadcaster lookupBroadcaster(String topic, String restOfTheUrl) {
        String pathInfo = topic + SLASH + restOfTheUrl;
        String[] decodedPath = pathInfo.split(SLASH);
        return BroadcasterFactory.getDefault().lookup(decodedPath[decodedPath.length - 1], true);
    }
}