/**
 *UDPServer
 *@author Winty wintys@gmail.com
 *@version 2008-12-15
 */
import java.io.*;
import java.net.*;
class UDPServer{
	public static void main(String[] args)throws IOException{
		//DatagramSocket  server = new DatagramSocket(5050);

		int ser_port = 5050;

		int argc = args.length;
		int i = 0;

		while (i < argc)
		{
			System.out.printf("args[%d]:[%s]\n",i,args[i]);
			if (args[i].equals("-sp") && argc >= i + 1)
			{
				ser_port = Integer.parseInt(args[i + 1]);
				i = i + 2;
				continue;
			}
			else
			{
				System.out.printf("args[%d]:[%s] is not support! or need a arg \n",i,args[i]);
				System.exit(1);
			}

			
		}

		DatagramSocket  server = new DatagramSocket(ser_port);

		//InetAddress my = InetAddress.getLocalHost(); 
		InetAddress my = InetAddress.getByName("127.0.0.1");
		String myAddr = my.toString();

		System.out.printf("myAddr:%s\n",myAddr);

		while(true)
		{
			byte[] recvBuf = new byte[4096];
			DatagramPacket recvPacket 
				= new DatagramPacket(recvBuf , recvBuf.length);

			server.receive(recvPacket);
			String recvStr = new String(recvPacket.getData() , 0 , recvPacket.getLength());
			System.out.println("from client:" + recvStr);

			int port = recvPacket.getPort();
			InetAddress addr = recvPacket.getAddress();

			String sendStr = addr.toString() + ":" + port ;
			System.out.println(sendStr);

			String cliAddr = addr.toString();
			System.out.printf("cliAddr:%s\n",cliAddr);

			byte[] sendBuf;
			sendBuf = sendStr.getBytes();
			DatagramPacket sendPacket 
				= new DatagramPacket(sendBuf , sendBuf.length , addr , port );
			server.send(sendPacket);

			if(cliAddr.equals(myAddr))
			{
				if(recvStr.equals("quit"))
				{
					break;
				}
			}
		}
		server.close();
	}
}