AWT ItemListener Interface

The class which processes the ItemEvent should implement this interface.The object of that class must be registered with a component. The object can be registered using the addItemListener() method. When the action event occurs, that object's  itemStateChanged method is invoked.
Following is the declaration for java.awt.event.ItemListener interface:
public interface ItemListener
   extends EventListener
void itemStateChanged(ItemEvent e) 
 Invoked when an item has been selected or deselected by the user.
This interface inherits methods from the following interfaces:
java.awt.EventListener
java.awt.EventListener
Create the following java program using any editor of your choice in say D:/ > AWT > com > tutorialspoint > gui >
package com.tutorialspoint.gui;

import java.awt.*;
import java.awt.event.*;

public class AwtListenerDemo {
   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;

   public AwtListenerDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AwtListenerDemo  awtListenerDemo = new AwtListenerDemo();  
      awtListenerDemo.showItemListenerDemo();
   }

   private void prepareGUI(){
      mainFrame = new Frame("Java AWT Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
   
      headerLabel = new Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();        
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      controlPanel = new Panel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private void showItemListenerDemo(){
      headerLabel.setText("Listener in action: ItemListener");      
      Checkbox chkApple = new Checkbox("Apple");
      Checkbox chkMango = new Checkbox("Mango");
      Checkbox chkPeer = new Checkbox("Peer");
      
      chkApple.addItemListener(new CustomItemListener());
      chkMango.addItemListener(new CustomItemListener());
      chkPeer.addItemListener(new CustomItemListener());

      controlPanel.add(chkApple);
      controlPanel.add(chkMango);
      controlPanel.add(chkPeer);               
      mainFrame.setVisible(true); 
   }

   class CustomItemListener implements ItemListener {
      public void itemStateChanged(ItemEvent e) {
         statusLabel.setText(e.getItem()
         +" Checkbox: " 
         + (e.getStateChange()==1?"checked":"unchecked"));
      }    
   }
}
Compile the program using command prompt. Go to D:/ > AWT  and type the following command.
D:\AWT>javac com\tutorialspoint\gui\AwtListenerDemo.java
If no error comes that means compilation is successful. Run the program using following command.
D:\AWT>java com.tutorialspoint.gui.AwtListenerDemo
Verify the following output

    13 Lectures 
     2 hours 

 EduOLC
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