addMouseListener or addActionListener or JButton?

Question

When defining the behaviour of a simple click on a JButton, which is the right way to do it? And, what's the difference?

JButton but = new JButton();
but.addActionListener(new ActionListener() {          
    public void actionPerformed(ActionEvent e) {
         System.out.println("You clicked the button, using an ActionListener");
    }
}); 

or

JButton but = new JButton();
but.addMouseListener(new java.awt.event.MouseAdapter() {
    public void mouseClicked(java.awt.event.MouseEvent evt) {
        System.out.println("You clicked the button, using a MouseListenr");
    }
});

Answer 1

MouseListener is a low-level event listener in Swing (and AWT by the way).

ActionListener is higher-level and should be used.

Better than ActionListener though, one should use a javax.swing.Action (which is actually an ActionListener).

Using an Action allows to share it among several widgets (eg JButton, JMenuItem...); not only do you share the code that is triggered when the button/menu is pushed, but also the state is shared, in particular the fact whether the action (and its associated widgets) is enabled or not.

Answer 2

You should be able to press that button using keyboard also. So, if you add just the mouse listener you will not get the 'press' event if using keyboard.

I would go for the action listener, it's more clear.