Learning Java but have problem displaying dialog

Question

I am learning Java by building a Platform based application. I have build the basic structure with several menu items and successfuly build two set of modules (an XML file reader and a set of initilization rouitnes. I amnow branching into a module to execute when a menu item is selected. I want to display a new window/dialog that contains a table showing the user options. However, I never get anythng displayed. The following code is from the menuitem handler. I commented out the logic I want to start working with, in an attempt to get something displayed. No Luck. I really need some help.
public final class EditPreferences implements ActionListener {
     @Override
     public void actionPerformed(ActionEvent e) {
          JFrame frame = new JFrame("User and Project Preferences");
          JPanel panel = new JPanel();
//          JTable table = new JTable( new PrefTableModel() );
//          table.setRowSelectionAllowed(false);
//          JScrollPane pane = new JScrollPane(table);
//          table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
//          panel.add(pane);
          frame.add(panel);
          frame.setVisible(true);
}I have been looking and reading all over the web and cannot figure this out. I think it should work, but is does not.

Answer 1

If "frame" is a JFrame, as it is in your code, then (as of Java 5) frame.add(panel) is the same as frame.getContentPane().add(panel) . See Javadoc for JFrame.add . So, that's not your problem here.
Try calling:
frame.pack();before you call frame.setVisible. And, of course, uncomment the lines. Right now, your JFrame will still look empty, because your JPanel is empty.
If you just want to see if a JFrame will display, you could replace the commented lines with something very simple:
// Default layout of content pane is BorderLayout, default location is BorderLayout.CENTER
panel.add(new JLabel("This is just a test."));