Question

I’m new to Swing and need some help with action listeners. I have seen them used like this example:

button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        // Do something
    }
});

However I want to do something more like this:

button.addActionListener(myFunc);

public void myFunc(ActionEvent e) 
{
   // Do something
}

Is this possible?

Answer 1

Two possible approaches here – either you can just call your myFunc method directly from within the first example you give:

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

…Or you can define an inner class that implements actionlistener and then use that:

class MyActionListener implements ActionListener {
    public void actionPerformed(ActionEvent e) { 
        //Your code
    }
}

button.addActionListener(new MyActionListener());

On a futuristic note, when Java 8 hits the shelves (2013, so don’t hold your breath) you’ll be able to do this more concisely using closures.