Hi can anyone help me on this..I am tying to change the UIManager.

 UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");

This gives me a lot of Exception.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.plaf.synth.SynthLookAndFeel.paintRegion(SynthLookAndFeel.java:364)
    at javax.swing.plaf.synth.SynthLookAndFeel.update(SynthLookAndFeel.java:328)
    at javax.swing.plaf.synth.SynthRootPaneUI.update(SynthRootPaneUI.java:120)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:295)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.plaf.synth.SynthLookAndFeel.paintRegion(SynthLookAndFeel.java:364)
    at javax.swing.plaf.synth.SynthLookAndFeel.update(SynthLookAndFeel.java:328)
    at javax.swing.plaf.synth.SynthTableHeaderUI.update(SynthTableHeaderUI.java:141)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JViewport.paint(JViewport.java:725)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:295)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Process completed.

Thank you in advance.

because you are using an object you haven't instantiated (yet)

This is inside in my main method()

        try
          {

            GuiStudent gs =  new GuiStudent();
            StudentRecord sr = new StudentRecord(10);
            UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
            SwingUtilities.updateComponentTreeUI(gs);


          }
          catch(Exception ex)
          {
            System.out.print("Error" + ex.getMessage());
          }

Can you make a small, simple, complete program that compiles, executes and shows the problem?

@NormR1, my problem is that when i am going to put this code in my main()
My Gui will shows but it has an exception.although it will run...but if i will not use UImanager it will runs without problem.

   public static void main(String []args)
   {

       try
          {
             GuiStudent gs =  new GuiStudent();
             StudentRecord sr = new StudentRecord(10);

            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
            SwingUtilities.updateComponentTreeUI(gs);


          }
          catch(Exception ex)
          {
            System.out.print("Error" + ex.getMessage());
          }
      } 

and what is UIManager? which line throws the exception exactly?

Can you make a program for testing?

@NormR1 @stultuske,I don't know which one.but i posted the exception above.can i ask how can i change the lookandfeel into NimbusLookAndFeel.?

jemz, your stacktrace tells you exactly on what line the exception is thrown. since we don't know your original code, we can't tell what the line is, but you should be able to find it.

I fixed it now.

You can look at this link or this link for how to enable Nimbus look and feel...

Thanks, i fixed it should not be put in the main method.