Home » Core Java » class » Anonymous inner class – Part 2

About Ilias Tsagklis

Ilias is a software developer turned online entrepreneur. He is co-founder and Executive Editor at Java Code Geeks.

Anonymous inner class – Part 2

This is an example of how to use an anonymous inner class. We have created a class, TalkingClock, that is a clock that prints the time in regular intervals and use it in another class, as described in the following steps:

  • TalkingClock has a method start(int interval, final boolean beat). The method creates a new ActionListener object that overrides the actionPerformed(ActionEvent event) of the ActionListener interface. This method will be invoked when the action will occur. In this method a new Date object is created and an audio beep is emitted, with beep() API method of Toolkit.
  • A new Timer is created in the start(int interval, final boolean beat) method to fire the ActionEvent at a given interval and its start() method is used.
  • We create a new instance of TalkingClock and call its start(int interval, final boolean beat) method.
  • We also bring up an information-message dialog titled with the message “Quit Program?”, using showMessageDialog(Component parentComponent, Object message) API method of JOptionPane.
  • The program will keep running until the user selects OK. Then the System.exit(0) to end the application.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;

import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import javax.swing.JOptionPane;
import javax.swing.Timer;

public class AnonymousInnerClassTest {

    public static void main(String[] args) {

  

  TalkingClock timer = new TalkingClock();

  timer.start(1000, true);


  // keep program running until user selects "Ok"

  JOptionPane.showMessageDialog(null, "Quit program?");

  System.exit(0);
    }
}
/**
 * A clock that prints the time in regular intervals.
 */
class TalkingClock {
    /**
     * Starts the clock.
     *
     */
    public void start(int interval, final boolean beat) {

  ActionListener listener = new ActionListener() {



@Override


public void actionPerformed(ActionEvent event) {


    Date now = new Date();


    System.out.println("The time is " + now);


    


    if (beat){



  Toolkit.getDefaultToolkit().beep();


    }


}

  };

  Timer timer= new Timer(interval, listener);

  timer.start();
    }
}

  
This was an example of how to use an anonymous inner class in Java.

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

 

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

6. Spring Interview Questions

7. Android UI Design

 

and many more ....

 

Receive Java & Developer job alerts in your Area

I have read and agree to the terms & conditions

 

Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

0 Comments
Inline Feedbacks
View all comments