Re: Query:the real function of System.exit(0)?

From:

Jack Dowson <jckdwsn@aol.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 13 May 2007 01:37:38 +0800

Message-ID:

<f250mt$e0e$1@news.cn99.com>

Thank you so much for helping me again,Andrew.

That is most probably the problem. If you spelt the
method name incorrectly, or using wrong arguments
using a WindowAdapter gives no complaint at compile
time, and no effect at runtime. Try implementing a
WindowListener instead - that forces you to implement
the correct methods.

I've checked every word I spelled,and found nothing wrong.

See if this example works for you..
<sscce>
import java.awt.event.*;
//import java.awt.Frame;
import javax.swing.JFrame;

class CloseWindow {

   public static void main(String[] args) {
      //Frame f = new Frame("Close Me!");
      JFrame f = new JFrame("Close Me!");

      f.addWindowListener( new WindowListener(){
         public void windowDeactivated(WindowEvent we) {}
         public void windowActivated(WindowEvent we) {}

         public void windowDeiconified(WindowEvent we) {}
         public void windowIconified(WindowEvent we) {}

         public void windowOpened(WindowEvent we) {}
         public void windowClosed(WindowEvent we) {}
         public void windowClosing(WindowEvent we) {
            System.out.println(we);
            System.exit(0);
         }
      } );

      f.setSize(200,100);
      f.setLocation(50,50);
      f.setVisible(true);
   }
}
</sscce>

I've tried,and the system replied:
java.awt.event.WindowEvent[WINDOW_CLOSING,opposite=null,oldState=0,newState=0]
on frame0
and then went back to the former condition.
It was the same result when I uncommented the two commented lines and
commented the two lines following them.
Why?

Dowson.