Atmosphere Java Servlet Server Sent Events

Question

This is my first time i'm working with atmosphere and for me its pretty tough. What i want is, that a user receives a push message from my API (Java Servlet / Tomcat).

I'm using jquery.atmosphere.js and following application code:

checkForMenuUpdates: function () {
        var self = this;
        checkUpdates();
        function checkUpdates() {
            var request = {url: path.apiPath + 'user.checkUpdates?token=' + token,                    
                logLevel: 'debug',
                'enableXDR': true,
                transport: 'sse',
                trackMessageLength: "false",
                fallbackTransport: 'long-polling'};

            request.onOpen = function (response) {

            };
            request.onMessage = function (response) {

            }
            var socket = jqueryAtmosphere;
            var subSocket = socket.subscribe(request);
        }

    },

The server side: Controller:

  else if ("user.checkUpdates".equals(pathInfo)) {
            try {
              AtmosphereBroadcaster atmo=new AtmosphereBroadcaster();
              atmo.subscribe(response);
                //ServerSentEvents updates = new ServerSentEvents();
                //updates.establishConnection(token.getUserId(), response, callback);
            } catch (Exception ex) {
                ErrorHandler error = new ErrorHandler();
                error.Error400(response, callback);
            }
        }

The "Broadcaster":

private @PathParam("token")
Broadcaster topic;

public SuspendResponse<String> subscribe(HttpServletResponse httpResponse) {
    StandardResponse res = new StandardResponse();
    httpResponse = res.standardResponseSSE(httpResponse);
    return new SuspendResponse.SuspendResponseBuilder<String>()
            .broadcaster(topic)
            .outputComments(true)
            .addListener(new EventsLogger())
            .build();

}

public static void push(String message, String topic) {

    Collection<Broadcaster> broadcasters = BroadcasterFactory.getDefault().lookupAll();

    for (Broadcaster b : broadcasters) {
        System.out.println(b.toString());
    }

    System.out.println("Request to push- Message: " + message + ", Topic: " + topic);
    Broadcaster b = null;
    if (null != (b = BroadcasterFactory.getDefault().lookup(JerseyBroadcaster.class, topic))) {
        System.out.println("Request to push- Message: " + message + ", Topic: " + topic);
        b.broadcast(message + "\n");
    }
}

private class EventsLogger implements AtmosphereResourceEventListener {

    @Override
    public void onPreSuspend(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onSuspend(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onResume(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onDisconnect(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onBroadcast(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onThrowable(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onClose(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void onHeartbeat(AtmosphereResourceEvent are) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
}

And the StandardResponse:

  public HttpServletResponse standardResponseSSE(HttpServletResponse response) {        
    response.setContentType("text/event-stream");
    response.setCharacterEncoding("UTF-8");
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setDateHeader("Expires", -1);
    return response;
}

And i get following output from the chrome console:

SSE successfully opened jquery.atmosphere.js?bust=6539327597711.235:3171 SSE reconnect maximum try reached 6

For me that sounds like there is no return message. I had a really basic example (https://weblogs.java.net/blog/swchan2/archive/2014/05/21/server-sent-events-async-servlet-example) which was working fine. But for me SSE doesn't work with atmosphere framework.

So whats the point here? What am i doing wrong?

EDIT:

I know the javascript code is strange - its "under construction" :)

Of course - when i add this code to the EventsLogger it is working:

public EventsLogger(HttpServletResponse response) {
        PrintWriter write = null;

        try {
            write = response.getWriter();
            while (true) {
                write.write("data:Test \n\n");
                write.flush();
                Thread.sleep(1000);
            }

        } catch (IOException ex) {
            Logger.getLogger(AtmosphereBroadcaster.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InterruptedException ex) {
            Logger.getLogger(AtmosphereBroadcaster.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            write.close();
        }
    }

It is a problem with the heartbeat that is not sending correctly - how to solve this?

Answer 1

Stop doing:

    throw new UnsupportedOperationException("Not supported yet.");

in the listener and that will work :-)