Java Client-Trouble Shooting

Last modified by David Avendasora on 2009/02/05 15:46

Exception in thread "AWT-EventQueue-0" com.webobjects.foundation.NSForwardException for java.lang.NoClassDefFoundError: my.app.package.ClassIKnowExists

When you get an error stating that WebObjects can't find a class on the client you know exists and is being copied to the WebServerResources/Java directory, then it is almost certainly a class-path issue. If you are running your app within Eclipse/WOLips, this means that the ClasspathClient.txt file is incorrect. This file is NOT maintained by the build process so any new Frameworks you add will need to be added to this file.

<com.webobjects.eodistribution._EOHTTPInitialAction>: Exception in performActionNamed() on the action "componentURL" with the message: java.lang.NullPointerException


Feb 05 15:42:58 FrameworkForTeachingD2JC[55677] WARN  NSLog  - <com.webobjects.eodistribution._EOHTTPInitialAction>: Exception in performActionNamed() on the action "componentURL" with the message: java.lang.NullPointerException
[2009-02-05 15:42:58 EST] <WorkerThread0> java.lang.NullPointerException
at com.webobjects.eodistribution._EOHTTPInitialAction.componentURLAction(_EOHTTPInitialAction.java:44)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.webobjects.appserver.WODirectAction.performActionNamed(WODirectAction.java:128)
at com.webobjects.appserver._private.WOActionRequestHandler._handleRequest(WOActionRequestHandler.java:240)
at com.webobjects.appserver._private.WOActionRequestHandler.handleRequest(WOActionRequestHandler.java:142)
at er.extensions.appserver.ERXDirectActionRequestHandler.handleRequest(ERXDirectActionRequestHandler.java:123)
at com.webobjects.appserver.WOApplication.dispatchRequest(WOApplication.java:1306)
at er.extensions.appserver.ERXApplication.dispatchRequestImmediately(ERXApplication.java:1737)
at er.extensions.appserver.ERXApplication.dispatchRequest(ERXApplication.java:1702)
at com.webobjects.appserver._private.WOWorkerThread.runOnce(WOWorkerThread.java:173)
at com.webobjects.appserver._private.WOWorkerThread.run(WOWorkerThread.java:254)
at java.lang.Thread.run(Thread.java:613)

You will get this error if you name the JavaClient.wo component to anything else and try to launch the application using the Client Launch Script. The Client Launch Script looks specifically for a Component named JavaClient.wo and if it can't find it it will trigger this NPE.