import java.awt.event.*; import javax.swing.*; class CloseableFrame extends JFrame { public CloseableFrame() { setTitle("My Closeable Frame"); setSize( 300, 200); // cause window events to be sent to window listener object addWindowListener( new MyWindowListener()); } } class MyWindowListener implements WindowListener { // Do nothing methods required by interface public void windowActivated( WindowEvent e) {} public void windowDeactivated( WindowEvent e) {} public void windowIconified( WindowEvent e) {} public void windowDeiconified( WindowEvent e) {} public void windowOpened( WindowEvent e) {} public void windowClosed( WindowEvent e) {} // override windowClosing method to exit program public void windowClosing( WindowEvent e) { System.exit( 0); // normal exit } } class Main { public static void main( String[] args) { CloseableFrame f = new CloseableFrame(); f.show(); // makes the frame visible new CloseableFrame().show(); f.setTitle("Karl"); } }