import java.net.*; import java.io.*; public class UDPEchoClient { public static void main(String[] args) { String hostname; int echoPort = 7; if (args.length > 0) { hostname = args[0]; } else { hostname = "localhost"; } try { InetAddress ia = InetAddress.getByName(hostname); DatagramSocket theSocket = new DatagramSocket(); echoInputThread eit = new echoInputThread(ia, theSocket); eit.start(); echoOutputThread eot = new echoOutputThread(theSocket); eot.start(); } catch (UnknownHostException e) { System.err.println(e); } catch (SocketException se) { System.err.println(se); } } // end main }