Draw line in JFrame

Source code below will draw a line from top left corner of a JFrame until bottom right corner of the JFrame.

************************************************************************
COMPLETE SOURCE CODE FOR : DrawLineInJFrame.java
************************************************************************

import javax.swing.JFrame;

import java.awt.Graphics;

public class DrawLineInJFrame extends JFrame
{
public DrawLineInJFrame()
{
 //Set JFrame title
 super("Draw A Line In JFrame");

 //Set default close operation for JFrame
 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

 //Set JFrame size
 setSize(400,400);

 //Make JFrame visible 
 setVisible(true);
}

public void paint(Graphics g)
{
 super.paint(g);

 //draw line in JFrame from top left corner until bottom right corner
 g.drawLine(0,0,getSize().width,getSize().height);
}

public static void main(String[]args)
{
 DrawLineInJFrame dlijf=new DrawLineInJFrame();
}
}

************************************************************************
JUST COMPILE AND EXECUTE IT
************************************************************************

Java source code to determine when application exit by print a line of text on command prompt

*************************************************************
COMPLETE SOURCE CODE FOR : DetermineWhenApplicationExit.java
*************************************************************

public class DetermineWhenApplicationExit
{
public static void main(String[]args)
{
 Runtime.getRuntime().addShutdownHook(new Thread()
 {
  public void run()
  {
   //Application will print "BYE" when it close
   System.out.println("BYE");
  }
 });

 //Make this application terminate
 System.exit(0);
}
}

*************************************************************
JUST COMPILE AND EXECUTE IT
*************************************************************