Name: rk38400 Date: 04/07/98


In Swing 1.0, if a frame has a JMenuBar, and any
submenu of that menubar is empty, a NullPointerException
will be throw during event processing for any
keyboard action.

Compile and run the following code:

import com.sun.java.swing.*;
import java.awt.*;

public class foo
   {
   public static void main(String[] args)
   {
      JFrame frame = new JFrame();
      JTextArea text = new JTextArea();
      JPanel panel = new JPanel(new GridLayout(1,1));
      panel.setPreferredSize(new Dimension(100,100));
      panel.add(text);
      frame.setContentPane(panel);

      JMenuBar menu = new JMenuBar();
      menu.add(new JMenu("something"));

      frame.setJMenuBar(menu);

      frame.pack();
      frame.setVisible(true);
      frame.validate();
      frame.repaint();
   }
   }

Now, type a letter in the text field: The program
will dump 2 identical stack traces:

Exception occurred during event dispatching:
java.lang.NullPointerException:
at com.sun.java.swing.JMenuBar.bindingForKeyStrokeRecursive(JMenuBar.java:559)
at com.sun.java.swing.JMenuBar.bindingForKeyStroke(JMenuBar.java:532)
at com.sun.java.swing.JComponent.processKeyBinding(JComponent.java:1345)
at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1402)
at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
at com.sun.java.swing.JComponent.processKeyBindings(JComponent.java:1391)
at com.sun.java.swing.JComponent.processKeyEvent(JComponent.java:1277)
at java.awt.Component.processEvent(Component.java:2138)
at java.awt.Container.processEvent(Container.java:894)
at java.awt.Component.dispatchEventImpl(Component.java:1764)
at java.awt.Container.dispatchEventImpl(Container.java:939)
at java.awt.Component.dispatchEvent(Component.java:1704)
at java.awt.LightweightDispatcher.processKeyEvent(Container.java:1416)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:1402)
at java.awt.Container.dispatchEventImpl(Container.java:926)
at java.awt.Window.dispatchEventImpl(Window.java:443)
at java.awt.Component.dispatchEvent(Component.java:1704)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:63)

I reported this a few days ago, but did not receive
an automatic reply.
(Review ID: 25834)
======================================================================