JButton gains focus when Hitting tab key but hitting Enter has no effect.

Question

Hi,
I have a program that has two buttons. When pressed, using the mouse, the buttons text appears in the middle of the screen. I have NOT alerted the focus subsystem. Thus when I press the tab key the buttons are highlighted in turn, to indicate that they currently have focus. However if I press enter the buttons actions (to update the middle of the screen with it's text) does not get activated.
I am using 1.4.2 on a Windows machine.
any help on this would be much appreciated !!
The code is as follows:
package com.logicacmg.skynet.tms.mmi.ui;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.Container;
public class Test implements ActionListener
JButton bTwo = new JButton("button 2");
JButton b = new JButton("button 1");
JLabel label = new JLabel(" ");
/** Creates a new instance of Test */
public Test()
JFrame frame = new JFrame();
//Create a panel to hold the MMI screens.
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BorderLayout());
b.addActionListener(this);
bTwo.addActionListener(this);
mainPanel.add(b, BorderLayout.WEST);
mainPanel.add(bTwo, BorderLayout.EAST);
mainPanel.add(label, BorderLayout.CENTER);
//add the main panel which contains the screens and the status bar
//to this frame.
Container contentPane = frame.getContentPane();
     contentPane.add(mainPanel, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
public static void main(String [] args)
new Test();
public void actionPerformed(ActionEvent e)
JButton aButton = (JButton)e.getSource();
if(aButton == b)
label.setText("one");
else if(aButton == bTwo)
label.setText("Two");

Answer 1

Which plaf are you using? Because when I switch to the windows plaf, the behavior is what you describe.
Demo:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class X {
    public static void main(String[] args) {
        final JFrame f = new JFrame("button focus");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        ActionListener al = new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                System.out.println(evt.getActionCommand());
        Container cp = f.getContentPane();
        cp.setLayout(new FlowLayout());
        for(int i=0; i<3; ++i) {
            JButton btn = new JButton("Button " + i);
            btn.addActionListener(al);
            cp.add(btn);
            if (i == 1)
                f.getRootPane().setDefaultButton(btn);
        final JCheckBox laf = new JCheckBox("platform plaf");
        laf.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent evt) {
                String cls = laf.isSelected() ? UIManager.getSystemLookAndFeelClassName() :
                  UIManager.getCrossPlatformLookAndFeelClassName();
                try {
                    UIManager.setLookAndFeel(cls);
                    SwingUtilities.updateComponentTreeUI(f);
                } catch (Exception e) {
                    e.printStackTrace();
        cp.add(laf);
        f.pack();
        f.setVisible(true);
}