SWING – ActionListener Interface

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SWING – ActionListener Interface

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The class which processes the ActionEvent should implement this interface. The object of that class must be registered with a component. The object can be registered using the addActionListener() method. When the action event occurs, that object’s actionPerformed method is invoked.

Interface Declaration

Following is the declaration for java.awt.event.ActionListener interface −

public interface ActionListener
   extends EventListener

Interface Methods

Sr.No.
Method & Description

1

void actionPerformed(ActionEvent e)

Invoked when an action occurs.

Methods Inherited

This interface inherits methods from the following interfaces −

java.awt.EventListener

ActionListener Example

Create the following Java program using any editor of your choice in say D:/ > SWING > com > tutorialspoint > gui >

SwingListenerDemo.java

package com.tutorialspoint.gui;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SwingListenerDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public SwingListenerDemo(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingListenerDemo  swingListenerDemo = new SwingListenerDemo();  
      swingListenerDemo.showActionListenerDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);        
      statusLabel.setSize(350,100);
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());
      
      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showActionListenerDemo(){
      headerLabel.setText("Listener in action: ActionListener");      

      JPanel panel = new JPanel();      
      panel.setBackground(Color.magenta);            
      JButton okButton = new JButton("OK");

      okButton.addActionListener(new CustomActionListener());        
      panel.add(okButton);
      controlPanel.add(panel);
      mainFrame.setVisible(true); 
   }
   class CustomActionListener implements ActionListener{
      public void actionPerformed(ActionEvent e) {
         statusLabel.setText("Ok Button Clicked.");
      }
   }	
}

Compile the program using the command prompt. Go to D:/ > SWING and type the following command.

D:\SWING>javac com\tutorialspoint\gui\SwingListenerDemo.java

If no error occurs, it means the compilation is successful. Run the program using the following command.

D:\SWING>java com.tutorialspoint.gui.SwingListenerDemo

Verify the following output.

SWING ActionListener

swing_event_listeners.htm

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