sketcher2/src/com/jotuntech/sketcher/server/VoiceServer.java

package com.jotuntech.sketcher.server;

import java.io.IOException;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.HashMap;

public class VoiceServer extends Thread {
	public final static int SPEEX_FRAME_BYTES = 640;
	private HashMap<Integer, InetSocketAddress> clients = new HashMap<Integer, InetSocketAddress>();
	ByteBuffer packetBuffer;
	int listenPort;

	public VoiceServer(int listenPort) {
		super("VoiceServer");
		this.listenPort = listenPort;
	}

	public void run() {
		System.err.println("Voice server started.");
		packetBuffer = ByteBuffer.allocate(SPEEX_FRAME_BYTES + 8);

		DatagramChannel channel = null;
		try {
			channel = DatagramChannel.open();
			channel.configureBlocking(true);
			DatagramSocket socket = channel.socket();
			socket.bind(new InetSocketAddress(listenPort));
			channel.configureBlocking(false);

			while(!interrupted()) {
				sleep(10);

				for(SocketAddress source = channel.receive(packetBuffer); source != null; source = channel.receive(packetBuffer)) {
					packetBuffer.flip();
					Integer sourceKey = packetBuffer.getInt(0);
					/** Allow only familiar clients */
					if(clients.containsKey(sourceKey)) {
						if(clients.get(sourceKey) == null || !clients.get(sourceKey).equals(source)) {
							/** Client is familiar but needs to be assigned an address */
							clients.put(sourceKey, (InetSocketAddress) source);
							System.err.println("Assigning address " + source + " to client " + sourceKey);
						}
						synchronized(clients) {
							for(InetSocketAddress address : clients.values()) {
								if(address == null) {
									/** Send only to clients with assigned addresses */
									continue;
								}
								if(address.equals(source)) {
									/** Send only to other clients than source of packet */
									continue;
								}
								if(channel.send(packetBuffer, address) > 0) {
									packetBuffer.flip();
								} else {
									System.err.println("Dropped packet.");
								}
							}
						}
					}
					packetBuffer.clear();
				}
			}
		} catch(InterruptedException e) {

		} catch (IOException e) {
			e.printStackTrace();
		}

		try {
			if(channel != null) {
				channel.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}

		System.err.println("Voice server interrupted.");
	}

	public void addClient(Integer peerKey) {
		synchronized(clients) {
			clients.put(peerKey, null);
		}
		System.err.println("Added client " + peerKey);
	}

	public void removeClient(Integer peerKey) {
		synchronized(clients) {
			clients.remove(peerKey);
		}
		System.err.println("Removed client " + peerKey);
	}
}