www.pudn.com > jnp-src.rar > MixedcastServer.java

/*
 * Java Network Programming, Second Edition
 * Merlin Hughes, Michael Shoffner, Derek Hamner
 * Manning Publications Company; ISBN 188477749X
 *
 * http://nitric.com/jnp/
 *
 * Copyright (c) 1997-1999 Merlin Hughes, Michael Shoffner, Derek Hamner;
 * all rights reserved; see license.txt for details.
 */

import java.io.*; 
import java.net.*; 
 
public class MixedcastServer { 
  public static void main (String[] args) throws IOException { 
    if ((args.length != 2) || (args[1].indexOf (":") < 0)) 
      throw new IllegalArgumentException 
        ("Syntax: MixedcastServer  :"); 
  
    int serverPort = Integer.parseInt (args[0]); 
    int idx = args[1].indexOf (":"); 
    InetAddress group = InetAddress.getByName (args[1].substring (0, idx)); 
    int port = Integer.parseInt (args[1].substring (idx + 1)); 
   
    init (serverPort, group, port); 
    while (true) { 
      relay (); 
    } 
  } 
 
  protected static DatagramSocket inSocket; 
  protected static MulticastSocket outSocket; 
  protected static DatagramPacket incoming, outgoing; 
 
  protected static void init (int serverPort, InetAddress group, int port) throws IOException { 
    inSocket = new DatagramSocket (serverPort); 
    outSocket = new MulticastSocket (); 
    outSocket.setTimeToLive (1); 
    byte[] buffer = new byte[65508]; 
    incoming = new DatagramPacket (buffer, buffer.length); 
    outgoing = new DatagramPacket (buffer, buffer.length, group, port); 
  } 
 
  protected static void relay () throws IOException { 
    incoming.setLength (incoming.getData ().length); 
    inSocket.receive (incoming); 
    outgoing.setLength (incoming.getLength ()); 
    outSocket.send (outgoing); 
  } 
}