Default button in JFrame is not firing when the enter key is being pressed

Question

I have a JFrame with three JButtons on it. I have set txtSearch (a JTextField component) to have the focus when JFrame loads. One of the buttons is set as the default button. This is my code:

private void formWindowOpened(java.awt.event.WindowEvent evt) 
{
     // btnRefresh.setMnemonic(KeyEvent.VK_R); // Even if this line 
                                               // is not commented, but
                                               // still the event wouldn't fire.
     this.getRootPane().setDefaultButton(btnRefresh);
}

When it loads, the button is just selected, but it did nothing when the Enter key was being pressed. How do I correctly implement it?

btnRefresh.addActionListener(new java.awt.event.ActionListener() {
    public void actionPerformed(java.awt.event.ActionEvent evt) {
        btnRefreshActionPerformed(evt);
    }
});

private void btnRefreshActionPerformed(java.awt.event.ActionEvent evt) {                                           
    JOptionPane.showMessageDialog(this, "Pressed!");
    // Other codes here (Replace by JOptionPane)
}  

Answer 1

What component has focus when the JFrame comes up? I ask because some components "eat" the Enter key event. For example, a JEditorPane will do that.

Also, when you assign an ActionListener to JTextField, the ActionListener will be called instead of the DefaultButton for the root pane. You must choose either to have an ActionListener or a DefaultButton, but you can't have both fire for the same JTextField. I'm sure this applies to other components as well.