//Example 8 of Chapter 9

import java.io.*;
import java.net.*;

public class NetIpAddressDatagramServerDemo
{
	private static DatagramSocket socket;
	public static void main( String args[] )
	{
		try {
			socket = new DatagramSocket( 1000 );
		}
		catch( SocketException socketException )
		{
			socketException.printStackTrace();
			System.exit( 1 );
		}
		while ( true )
		{
			try{
				byte data[] = new byte[ 100 ];
				DatagramPacket rp = new DatagramPacket( data, data.length );
				socket.receive( rp );
				DatagramPacket sendPacket = new DatagramPacket( 
					rp.getData(), rp.getLength(), rp.getAddress(), rp.getPort() );
				socket.send( sendPacket );
			}
			catch( IOException ioException )
			{
				ioException.printStackTrace();
			}
		}
	}
}