"AWT-EventQueue-0" java.lang.NullPointerException

Rahul Gupta · Post by **Rahul Gupta** » Mon May 02, 2005 1:09 pm

Ok,
everything on my project was working fine.
But sometimes when i opened tomcat console it gives exception like this :

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at sun.awt.Win32GraphicsEnvironment.displayChanged(Win32GraphicsEnvironment.java:109)
at sun.awt.windows.WToolkit$4.run(WToolkit.java:698)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:234)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

Well, I m using j2sdk1.5 and tomcat5.0.28 with struts1.1.

Can anyone help me to fix this problem. :(

Post by **Taqua** » Mon May 02, 2005 3:19 pm

Hi,

this looks like a JDK problem. There are neither Tomcat or JFreeChart classes involved here.

As the AWT seems to be the problem, you can try to disable access to the AWT by enabling the headless mode. You are running a server application and therefore you should not have need for AWT or Swing components anyway.

Have mo' fun,
said Thomas

P.S: Reporting the bug to Sun is also a good idea - they can't fix what they don't know of.

Hi Taqua, · Post by **Hi Taqua,** » Tue May 03, 2005 12:36 pm

I'll try this.

Thanks a lot.