From: Gerard Davison <gerard.davison_at_oracle.com>
Date: Mon, 29 Apr 2013 15:47:52 +0100

Hi,

So once I have resolved some of the maven issues I typed up a very simple echo example with the service:

package websocket;

import java.io.IOException;

import javax.websocket.Endpoint;
import javax.websocket.EndpointConfig;
import javax.websocket.MessageHandler;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint(value="/echo")
public class EchoBean
{
    
    @OnMessage
    public void echo (String message, Session peer) throws IOException {
        //
        System.out.println("Echoing " + message);
        System.out.println("Sending message to client");
        peer.getBasicRemote().sendText(message);
    }

    @OnOpen
    public void onOpen(final Session session, EndpointConfig endpointConfig) {
        System.out.println("Server connected " + session + " " + endpointConfig);
    }
}


And the client, which interestedly wouldn't work if it was just a annotated POJO - it had to extend Endpoint on the client side:

package websocket;

import java.io.IOException;

import javax.websocket.ClientEndpoint;
import javax.websocket.Endpoint;
import javax.websocket.EndpointConfig;
import javax.websocket.MessageHandler;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;

@ClientEndpoint
public class EchoBeanClient
  extends Endpoint
{


    public void onOpen(Session session, EndpointConfig endpointConfig) {
        System.out.println("Client Connection open " + session + " " + endpointConfig);
        
        // Add a listener
        
        session.addMessageHandler(new MessageHandler.Whole<String>() {

            @Override
            public void onMessage(String string) {
                System.out.println("Message from server : " + string);
            }
        });
        
        System.out.println("Sending message to server");
        session.getAsyncRemote().sendText("Hello");
        
    }
}

And finally the test method:


    public static void main(String[] args) throws DeploymentException, IOException {
       
        try
        {
            Server server = new Server("localhost", 8025, "/", EchoBean.class);
            
            server.start();

            // .start() doesn't mean server is ready to serve
            
            TimeUnit.SECONDS.sleep(5);
            
            // Right now we have to create a client
            

            ClientManager client = ClientManager.createClient();
            Session session = client.connectToServer(
                    EchoBeanClient.class,
                    ClientEndpointConfig.Builder.create().build(),
                    URI.create("ws://localhost:8025/echo"));
            
            
            session.getBasicRemote().sendText("Hello");


            //
            
            TimeUnit.SECONDS.sleep(5);

        }
        catch (Exception ex) {
            
            ex.printStackTrace(System.out);
        }


The problem is that the server gets the echo message twice, see the following output:

Apr 29, 2013 3:34:20 PM org.glassfish.tyrus.server.ServerContainerFactory create
INFO: Provider class loaded: org.glassfish.tyrus.container.grizzly.GrizzlyEngine
Apr 29, 2013 3:34:20 PM org.glassfish.grizzly.http.server.NetworkListener start
INFO: Started listener bound to [0.0.0.0:8025]
Apr 29, 2013 3:34:20 PM org.glassfish.grizzly.http.server.HttpServer start
INFO: [HttpServer] Started.
Apr 29, 2013 3:34:20 PM org.glassfish.tyrus.server.Server start
INFO: WebSocket Registered apps: URLs all start with ws://localhost:8025
Apr 29, 2013 3:34:20 PM org.glassfish.tyrus.server.Server start
INFO: WebSocket server started.
Server connected SessionImpl{uri=/echo, id='3ceec83b-3c9e-4889-8d0e-0d8dfbb6839f', endpoint=EndpointWrapper{endpointClass=null, endpoint=org.glassfish.tyrus.core.AnnotatedEndpoint_at_328f00, uri='/echo', contextPath='/'}} javax.websocket.server.DefaultServerEndpointConfig_at_14a5255
Client Connection open SessionImpl{uri=ws://localhost:8025/echo, id='fd1b240f-f59c-4a59-a1a9-77b2762cfa1b', endpoint=EndpointWrapper{endpointClass=null, endpoint=websocket.EchoBeanClient_at_ec120d, uri='ws://localhost:8025/echo', contextPath='ws://localhost:8025/echo'}} javax.websocket.DefaultClientEndpointConfig_at_954f73
Sending message to server
Echoing Hello
Sending message to client
Echoing Hello
Sending message to client
Message from server : Hello
Message from server : Hello

Is there something obvious missing from this code?

Thanks,

Gerard