/* * 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.awt.*;import java.rmi.*;import java.awt.event.*;import java.rmi.registry.*;public class RMIChatClient implements Runnable, ActionListener {  protected static final int UPDATE_DELAY = 10000;  protected String host;  protected Frame frame;  protected TextField input;  protected TextArea output;  public RMIChatClient (String host) {    this.host = host;    frame = new Frame ("RMIChatClient [" + host + "]");    frame.add (output = new TextArea (), "Center");    output.setEditable (false);    frame.add (input = new TextField (), "South");    input.addActionListener (this);    frame.addWindowListener (new WindowAdapter () {      public void windowOpened (WindowEvent ev) {        input.requestFocus ();      }            public void windowClosing (WindowEvent ev) {        stop ();      }    });    frame.pack ();  }  protected RMIChatServer server;  protected Thread updater;  public synchronized void start () throws RemoteException, NotBoundException {    if (updater == null) {      Registry registry = LocateRegistry.getRegistry (host);      server = (RMIChatServer) registry.lookup (RMIChatServer.REGISTRY_NAME);      updater = new Thread (this);      updater.start ();      frame.setVisible (true);    }  }  public synchronized void stop () {    if (updater != null) {      updater.interrupt ();      updater = null;      server = null;    }    frame.setVisible (false);  }  public void run () {    try {      int index = 0;      while (!Thread.interrupted ()) {        String[] messages = server.getMessages (index);        int n = messages.length;        for (int i = 0; i < n; ++ i)          output.append (messages[i] + "\n");        index += n;        Thread.sleep (UPDATE_DELAY);      }    } catch (InterruptedException ignored) {    } catch (RemoteException ex) {      input.setVisible (false);      frame.validate ();      ex.printStackTrace ();    }  }  public void actionPerformed (ActionEvent ev) {    try {      RMIChatServer server = this.server;      if (server != null)        server.addMessage (ev.getActionCommand ());      input.setText ("");    } catch (RemoteException ex) {      Thread tmp = updater;      updater = null;      if (tmp != null)        tmp.interrupt ();      input.setVisible (false);      frame.validate ();      ex.printStackTrace ();    }  }  public static void main (String[] args) throws RemoteException, NotBoundException {    if (args.length != 1)      throw new IllegalArgumentException ("Syntax: RMIChatClient <host>");    RMIChatClient chatClient = new RMIChatClient (args[0]);    chatClient.start ();  }}