I use Sun java sudio creator,but a error happen
java.lang.NullPointerException
at com.sun.rave.designer.DesignerTopComp.requestFocus(DesignerTopComp.java:191)
at org.netbeans.core.multiview.MultiViewPeer$SelectionListener.selectionActivatedB yButton(MultiViewPeer.java:485)
at org.netbeans.core.multiview.MultiViewModel.fireActivateCurrent(MultiViewModel.j ava:236)
at org.netbeans.core.multiview.TabsComponent$ButtonMouseListener.mouseClicked(Tabs Component.java:415)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:212)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:211)
at java.awt.Component.processMouseEvent(Component.java:5491)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
at java.awt.Component.processEvent(Component.java:5253)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3955)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3901)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1774)
at java.awt.Component.dispatchEvent(Component.java:3803)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java: 242)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:16 3)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
why ? who can help me? I can't work it.
