Java Programming

I wrote the fllowing code to deal with the clicking the button on ContentPane:

public void jMenuItemForegroundColor_actionPerformed(ActionEvent e) {
Color color = javax.swing.JColorChooser.showDialog(this, "Foreground Color",
jTextArea.getForeground());
if (color != null) {
jTextArea.setForeground(color);
}
}

but running the program , it throws exception:

java.lang.IllegalArgumentException: Invalid mnemonic index: 3

at javax.swing.JTabbedPane$Page.setDisplayedMnemonicIndex(JTabbedPane.java:1805)

at javax.swing.JTabbedPane.setDisplayedMnemonicIndexAt(JTabbedPane.java:1385)

at javax.swing.plaf.basic.BasicColorChooserUI$PropertyHandler.propertyChange(BasicColorChooserUI.java:238)

at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:264)

at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:232)

at javax.swing.JComponent.firePropertyChange(JComponent.java:3819)

at javax.swing.JColorChooser.setChooserPanels(JColorChooser.java:446)

at javax.swing.plaf.basic.BasicColorChooserUI.installUI(BasicColorChooserUI.java:79)

at javax.swing.JComponent.setUI(JComponent.java:449)

at javax.swing.JColorChooser.setUI(JColorChooser.java:209)

at javax.swing.JColorChooser.updateUI(JColorChooser.java:220)

at javax.swing.JColorChooser.<init>(JColorChooser.java:183)

at javax.swing.JColorChooser.<init>(JColorChooser.java:171)

at javax.swing.JColorChooser.showDialog(JColorChooser.java:115)

at mynotepad.EditTextFrame.jMenuItemForegroundColor_actionPerformed(EditTextFrame.java:181)

at mynotepad.EditTextFrame_jMenuItemForegroundColor_actionAdapter.actionPerformed(EditTextFrame.java:254)

at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1786)

at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1839)

at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)

at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)

at javax.swing.AbstractButton.doClick(AbstractButton.java:289)

at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1113)

at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(BasicMenuItemUI.java:943)

at java.awt.Component.processMouseEvent(Component.java:5100)

at java.awt.Component.processEvent(Component.java:4897)

at java.awt.Container.processEvent(Container.java:1569)

at java.awt.Component.dispatchEventImpl(Component.java:3615)

at java.awt.Container.dispatchEventImpl(Container.java:1627)

at java.awt.Component.dispatchEvent(Component.java:3477)

at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)

at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3198)

at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)

at java.awt.Container.dispatchEventImpl(Container.java:1613)

at java.awt.Window.dispatchEventImpl(Window.java:1606)

at java.awt.Component.dispatchEvent(Component.java:3477)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)

at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)

at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)


So,could any friends tell me what shall I do? How could I solve this bug , thank you .