ChatService.java

/**
 * 
 */
package org.cometd.demo;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.cometd.Bayeux;
import org.cometd.Channel;
import org.cometd.Client;
import org.cometd.RemoveListener;
import org.mortbay.cometd.BayeuxService;
import org.mortbay.log.Log;

public class ChatService extends BayeuxService
{
    /**
     * A map(channel, map(userName, clientId))
     */
    private final ConcurrentMap<String, Map<String, String>> _members = new ConcurrentHashMap<String, Map<String, String>>();
    
    public ChatService(Bayeux bayeux)
    {
        super(bayeux, "chat");
        subscribe("/chat/**", "trackMembers");
        subscribe("/service/privatechat", "privateChat");
    }
    
    public void trackMembers(final Client joiner, final String channelName, Map<String, Object> data, final String messageId)
    {
        if (Boolean.TRUE.equals(data.get("join")))
        {
            Map<String, String> membersMap = _members.get(channelName);
            if (membersMap == null)
            {
                Map<String, String> newMembersMap = new ConcurrentHashMap<String, String>();
                membersMap = _members.putIfAbsent(channelName, newMembersMap);
                if (membersMap == null) membersMap = newMembersMap;
            }
            
            final Map<String, String> members = membersMap;
            final String userName = (String)data.get("user");
            members.put(userName, joiner.getId());
            joiner.addListener(new RemoveListener()
            {
                public void removed(String clientId, boolean timeout)
                {
                    members.values().remove(clientId);
                    Log.info("members: " + members);
                    // Broadcast the members to all existing members
                    Channel channel = getBayeux().getChannel(channelName, false);
                    if (channel != null) channel.publish(getClient(), members.keySet(), messageId);
                }
            });

            Log.info("Members: " + members);
            // Broadcast the members to all existing members
            getBayeux().getChannel(channelName, false).publish(getClient(), members.keySet(), messageId);
        }
    }

    public void privateChat(Client source, String channel, Map<String, Object> data, String messageId)
    {
        String roomName = (String)data.get("room");
        Map<String, String> membersMap = _members.get(roomName);
        String peerName = (String)data.get("peer");
        String peerId = membersMap.get(peerName);
	if (peerId!=null)
        {
            Client peer = getBayeux().getClient(peerId);
	    if (peer!=null)
	    {
		Map<String, Object> message = new HashMap<String, Object>();
		message.put("chat", data.get("chat"));
		message.put("user", data.get("user"));
		message.put("scope", "private");
		peer.deliver(getClient(), roomName, message, messageId);
		source.deliver(getClient(), roomName, message, messageId);
		return;
            }
	}
	Map<String, Object> message = new HashMap<String, Object>();
	message.put("chat", "Unknown user: "+peerName);
	message.put("user", "SERVER");
	message.put("scope", "error");
	source.deliver(source, roomName, message, messageId);
    }
}