JavaxWebSocketChat.java

//
//  ========================================================================
//  Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package com.acme;

import java.io.IOException;
import java.util.List;
import java.util.ListIterator;
import java.util.concurrent.CopyOnWriteArrayList;

import javax.websocket.CloseReason;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.RemoteEndpoint;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint(value="/javax.websocket/", subprotocols={"chat"})
public class JavaxWebSocketChat
{
    private static final List<JavaxWebSocketChat> members = new CopyOnWriteArrayList<>();
    
    volatile Session session;
    volatile RemoteEndpoint.Async remote;
    
    @OnOpen
    public void onOpen(Session sess)
    {
        this.session = sess;
        this.remote = this.session.getAsyncRemote();
        members.add(this);
    }
    
    @OnMessage
    public void onMessage(String data)
    {
        if(data.contains("disconnect"))
        {
            try
            {
                session.close();
            }
            catch (IOException ignore)
            {
                /* ignore */
            }
            return;
        }
        
        ListIterator<JavaxWebSocketChat> iter = members.listIterator();
        while(iter.hasNext())
        {
            JavaxWebSocketChat member = iter.next();
            
            // Test if member is now disconnected
            if(!member.session.isOpen())
            {
                iter.remove();
                continue;
            }
            
            // Async write the message back
            member.remote.sendText(data);
        }
    }
    
    @OnClose
    public void onClose(CloseReason reason)
    {
        members.remove(this);
    }
}