Strange java constructor syntax

Question

It seems as if an ActionListener object were created with an inherited/overridden method. Has this syntax some special name?

btnLocationDev.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
               ...
    }
});

possible duplicate http://stackoverflow.com/questions/355167/how-are-anonymous-inner-classes-used-in-java — Drogba, Feb 20 '14 at 08:58

score 3 · Answer 1 · answered Feb 20 '14 at 08:54

3

It's called anonymous inner class. You just created an instance of anonymous inner class which implements ActionListener.

answered Feb 20 '14 at 08:54

Abimaran Kugathasan

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score 3 · Answer 2 · edited Mar 12 '20 at 16:13

3

It is an anonymous inner class. .

edited Mar 12 '20 at 16:13

peterh

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answered Feb 20 '14 at 08:54

Ruchira Gayan Ranaweera

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score 3 · Accepted Answer · answered Feb 20 '14 at 09:00

That is anonymous Inner class. It can actually come in handy when making an instance of an object which something extra such as overloading methods, without having to actually subclass a class. I use it mostly when i want to attach a listner.

When you conventionally attach a listner you have to overload each method but when you use annonymous inner class you just overload the method you want.

button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e)
    {
        // Method to be used.
    }
});

Strange java constructor syntax

3 Answers3