/* @(#) KeepAlive.java  Trivial keep-alive program. Tries at 5-second intervals
 *                      to find addresses for hosts with generated names. This
 *                      ensures that messages are sent to nameserver(s).
 *                      Copyright (c) 2002 Graham Jenkins <grahjenk@au1.ibm.com>
 *                      All rights reserved. Version 1.06, August 15, 2002.
 */
import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Date;
public class KeepAlive {
  public static void main(String[] args) {
    MessageFrame f=new MessageFrame();  // Change button colours each iteration.
    int flag=0;                         // Also switch frame-title so we can see
    while ( true ) {                    // activity whilst iconified.
      f.statusMess(Color.red,Color.red); f.setTitle("==X==");
      try {InetAddress addr=InetAddress.getByName("A"+(new Date()).getTime());}
      catch (UnknownHostException ioe) {}
      if(flag==0) {f.statusMess(Color.yellow,Color.green); f.setTitle("1.06");}
      else {f.statusMess(Color.green,Color.yellow); f.setTitle("KeepAlive");}
      flag=1-flag;
      try {Thread.sleep(5000L);} catch (InterruptedException e) {}
    }
  }
}

class MessageFrame extends Frame implements ActionListener {
  private Button b1, b2;                // Displays two coloured buttons.
  public MessageFrame() {
    Panel p=new Panel(); p.setLayout(new FlowLayout());
    b1=new Button() ; b2=new Button(); p.add(b1); p.add(b2);
    this.add("South",p); this.setSize(150,50); this.show();
    this.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) { System.exit(0); }
    });
  }
  public void statusMess(Color left, Color right) {
    b1.setBackground(left); b2.setBackground(right);
  }
  public void actionPerformed(ActionEvent e) {}
}