Anonymous class

[jacob deiter]

I hope every concept in java has pros. Can anyone explain what are the real-time use of Anonymous class. Please do not write theatrical definition which are available in Java books.If explain with example is more appreciative

[Rob Spoor]

I use anonymous classes for actions in Swing most of the time:

Action action = new AbstractAction("Action")
{
    public void actionPerformed(ActionEvent e)
    {
        // handle the action
    }
};

If I don't I end up writing dozens of named sub classes of AbstractAction in some of my programs.

[Campbell Ritchie]

And lots of us add anonymous ActionListeners to our Buttons. They look rather similar to Rob's example, and most books have them in. In fact I think a book which doesn't teach how to write an anonymous ActionListener probably isn't worth reading!

[Rob Spoor]

Actually, I hardly use ActionListeners for any of my buttons. I prefer (Abstract)Action - you can use a single Action object to share the text, icon, mnemonic and accelerator for multiple buttons. That includes JMenuItem.

And since Action extends ActionListener you get the event handling as well

[Campbell Ritchie]

Originally posted by Rob Prime:
And since Action extends ActionListener you get the event handling as well

So you do use ActionListeners

I see your point, they do appear to be an improvement on ActionListener.

[Steve Luke]

And just to throw in a non-GUI based example, I will use it a lot when using Runnables:

public class LongProcess {
    public void doALotOfWork() {
        ...
    }
    public void startWorking() {
        executor.submit(new Runnable() {
            public void run() {
                doALotOfWork();
            }
        });
    }