www.pudn.com > jnp-src.rar > ChatHandler.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.*; 
import java.util.*; 
 
public class ChatHandler implements Runnable { 
  protected Socket socket; 
   
  public ChatHandler (Socket socket) { 
    this.socket = socket; 
  } 
 
  protected DataInputStream dataIn; 
  protected DataOutputStream dataOut; 
  protected Thread listener; 
   
  public synchronized void start () { 
    if (listener == null) { 
      try { 
        dataIn = new DataInputStream 
          (new BufferedInputStream (socket.getInputStream ())); 
        dataOut = new DataOutputStream 
          (new BufferedOutputStream (socket.getOutputStream ())); 
        listener = new Thread (this); 
        listener.start (); 
      } catch (IOException ignored) { 
      } 
    } 
  } 
 
  public synchronized void stop () { 
    if (listener != null) { 
      try { 
        if (listener != Thread.currentThread ()) 
          listener.interrupt (); 
        listener = null; 
        dataOut.close (); 
      } catch (IOException ignored) { 
      } 
    } 
  } 
 
  protected static Vector handlers = new Vector (); 
   
  public void run () { 
    try { 
      handlers.addElement (this); 
      while (!Thread.interrupted ()) { 
        String message = dataIn.readUTF (); 
        broadcast (message); 
      } 
    } catch (EOFException ignored) { 
    } catch (IOException ex) { 
      if (listener == Thread.currentThread ()) 
        ex.printStackTrace (); 
    } finally { 
      handlers.removeElement (this); 
    } 
    stop (); 
  } 
 
  protected void broadcast (String message) { 
    synchronized (handlers) { 
      Enumeration enum = handlers.elements (); 
      while (enum.hasMoreElements ()) { 
        ChatHandler handler = (ChatHandler) enum.nextElement (); 
        try { 
          handler.dataOut.writeUTF (message); 
          handler.dataOut.flush (); 
        } catch (IOException ex) { 
          handler.stop (); 
        } 
      } 
    } 
  } 
}