package primer34;

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

public class UDPDiscardServer {

	public final static int DEFAULT_PORT = 9;
	public final static int MAX_PACKET_SIZE = 65507;
	
	public static void main(String[] args) {
		
		int port = DEFAULT_PORT;
		byte[] buffer = new byte[MAX_PACKET_SIZE];
		
		try{
			port = Integer.parseInt(args[0]);
		}catch(Exception ex){
			// use default port
		}
		
		try(DatagramSocket server = new DatagramSocket(port)){
						
			DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
			while(true){
				try{
					server.receive(packet);
					String s = new String(packet.getData(), 0, packet.getLength(),"UTF-8");
					System.out.println(packet.getAddress() + " at port "
							+ packet.getPort() + " says " + s);
					// reset the length for the next packet
					// za Windows XP i Linux Slackware testirano da radi i bez ovoga,
					// ali za druge sisteme nije, tako da ga ipak treba pisati
					packet.setLength(buffer.length);
				}catch(IOException ex){
					System.err.println(ex);
				}
			}// end while
		} // end try
		catch(SocketException ex){
			System.err.println(ex);
		}//end catch
	} // end main

}