WindowListener in Java Example

Window event occurs when window related activities such as closing, activating or deactivating a window are performed. Objects representing window events are created from WindowEvent class. The most common method of this class is

Window getWindow()

It returns the Window object that generated the event.

There are three listener interfaces corresponding to the WindowEvent class. These include WindowListener interface, WindowFocusListener interface and WindowStateListener interface. Each listener for WindowEvent should implement the appropriate interface. 

The methods of this interface are:

windowClosing () is called when you click on system closing the window box. WindowClosed () is called after closing the window: This method is only useful if the closure of the window does not cause the end of application.

import javax.swing.*;      
 import java.awt.event.*; 
 import java.awt.*; 
 class WindowListenerExample extends JFrame implements WindowListener 
 { 
        WindowListenerExample() 
        {   
           addWindowListener(this); 
        } 
        public void windowClosing(WindowEvent e) 
        { 
           System.out.println("Window Closing"); 
           dispose(); 
           System.exit(0); 
        } 
        public void windowOpened(WindowEvent e) 
           { System.out.println("Window Open"); } 
        public void windowClosed(WindowEvent e) 
           { System.out.println("Window Closed");} 
        public void windowActivated(WindowEvent e) 
           { System.out.println("Window Activated"); } 
        public void windowDeactivated(WindowEvent e) 
           { System.out.println("Window Deactivated"); } 
        public void windowIconified(WindowEvent e) 
           { System.out.println("window Iconified"); } 
        public void windowDeiconified(WindowEvent e) 
           { System.out.println("Window Deiconified"); } 
      } 
      class WindowListenerJavaExample 
     { 
        public static void main(String[] args) 
        { 
          WindowListenerExample frame = new WindowListenerExample(); 
          frame.setTitle("Window Listener Java Example"); 
          frame.setBounds(100,200,200,200); 
          frame.setVisible(true); 
        } 
    }