Re: Fwd: [platform-dev] Plugin ClassLoader Difficulties

[Chris McGee <cbmcgee@xxxxxxxxxx>]

Wow, it was staring me right in the
face.

Thank you for your help,

Chris

John Arthorne/Ottawa/IBM@IBMCA
Sent by: platform-dev-admin@xxxxxxxxxxx

02/20/2004 02:38 PM

Please respond to
platform-dev

To	platform-dev@xxxxxxxxxxx
cc
Subject	Re: Fwd: [platform-dev] Plugin ClassLoader Difficulties

The trick with these BundleActivator exceptions is to look for the "caused
by" line that precedes the exception that caused the bundle (aka plugin)
to fail to load.  In this case, it looks like it's because the plugin
tries to access the JFace ImageRegistry, but there is no Display (not surprising
for a headless ant script).  You generally can't be accessing UI components
from within a custom ant task. I don't know what plugin is being loaded
here because it was omitted from the stack trace: 

[diagram] Caused by: org.eclipse.jface.util.Assert$AssertionFailedException:
null argument;
[diagram] at org.eclipse.jface.util.Assert.isNotNull(Assert.java:139)
[diagram] at org.eclipse.jface.util.Assert.isNotNull(Assert.java:116)
[diagram] at org.eclipse.jface.resource.ImageRegistry.<init>(ImageRegistry.java:66)
[diagram] at org.eclipse.jface.resource.ImageRegistry.<init>(ImageRegistry.java:58)
<Some custom plugin resource manager stuff here>


> Subject: [platform-dev] Plugin ClassLoader Difficulties
> Date: February 20, 2004 01:18 pm
> From: Chris McGee <cbmcgee@xxxxxxxxxx>
> To: platform-dev@xxxxxxxxxxx
> 
> Hi All,
> 
> I'm having a very strange problem with the Plugin ClassLoader when
> executing my own custom Ant task. My environment is eclipse 3.0 M6
on
> Win2k.
> 
> Basically, I have an Ant task that I have created that makes use of
a
> plugin that I have developed. My plugin has dependencies on other
plugins
> and I hope to make use of these other plugins.
> 
> What I have done is to place my Ant task in a separate jar that is
no way
> referenced by my plugin. This is suggested by the Eclipse Ant
> documentation. My Ant task has references to classes in my plugin
and when
> I compile the class, I specify my plugin directory as part of the
classpath
> in order to resolve the references to classes in my plugin. I give
the ant
> task jar to Ant through the ant task extension point so that it can
load
> the class when it is needed.
> 
> The above approach seems to work well in simple cases where I do not
> attempt to access classes beyond my ant task class. I can complete
simple
> tasks with no problem. When I access classes from my plugin, exceptions
are
> thrown sometime. I have been able to access certain classes and perform
> static method invokations on them with no problems. The problems seem
to
> occur when I actually try to instantiate a class.
> 
> Here is an example stacktrace:
> 
> [diagram] org.osgi.framework.BundleException: Exception in
> org.eclipse.core.internal.compatibility.PluginActivator.start()
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1071) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at java.lang.ClassLoader.defineClass0(Native Method)
> [diagram] at java.lang.ClassLoader.defineClass(ClassLoader.java(Compiled
> Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.defineC
> lass(DefaultClassLoader.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.defineClass(EclipseClassL
> oader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findCla
> ssImpl(DefaultClassLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findCla
> ss(DefaultClassLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.findLocalClass(BundleCla
> ssLoader.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.loadClass(BundleLoader.
> java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java
> (Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.loadClass(Bundle.java(Compile
> d Code))
> [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.internalDoPluginActivation
> (PluginDescriptor.java:471) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.doPluginActivation(PluginD
> escriptor.java:438) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.getPlugin(PluginDescriptor
> .java:406) [diagram] at
> org.eclipse.core.internal.compatibility.PluginActivator.start(PluginActivator
> .java:48) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext$1.run(BundleContext.ja
> va:1054) [diagram] at java.security.AccessController.doPrivileged1(Native
>  Method) [diagram] at
> java.security.AccessController.doPrivileged(AccessController.java:350)
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1050) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at someplugin.someOperation.<init>(someOperation.java:47)
> [diagram] at ... CustomTask.execute(Unknown Source)
> [diagram] at
> org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
> [diagram] at org.apache.tools.ant.Task.perform(Task.java:401)
> [diagram] at org.apache.tools.ant.Target.execute(Target.java:338)
> [diagram] at org.apache.tools.ant.Target.performTasks(Target.java:365)
> [diagram] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
> [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:661) [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:438) [diagram] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
>  Method) [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:84)
> [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> [diagram] at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.
> java(Compiled Code))
> [diagram] at java.lang.reflect.Method.invoke(Method.java(Compiled
Code))
> [diagram] at org.eclipse.ant.core.AntRunner.run(AntRunner.java:342)
> [diagram] at
> org.eclipse.ant.internal.ui.launchConfigurations.AntLaunchDelegate.launch(Ant
> LaunchDelegate.java:225) [diagram] at
> org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguratio
> n.java:157) [diagram] at
> org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java
> :778) [diagram] at
> org.eclipse.debug.ui.DebugUITools.buildAndLaunch(DebugUITools.java:628)
> [diagram] at org.eclipse.debug.ui.DebugUITools$2.run(DebugUITools.java:536)
> [diagram] at
> org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.
> java:101) [diagram] java.lang.ExceptionInInitializerError
> [diagram] at some.plugin.somePlugin.<clinit>(somePlugin.java:49)
> [diagram] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
> Method)
> [diagram] at
> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccess
> orImpl.java:79) [diagram] at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstruct
> orAccessorImpl.java(Compiled Code))
> [diagram] at
> java.lang.reflect.Constructor.newInstance(Constructor.java(Compiled
Code))
> [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.internalDoPluginActivation
> (PluginDescriptor.java:488) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.doPluginActivation(PluginD
> escriptor.java:438) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.getPlugin(PluginDescriptor
> .java:406) [diagram] at
> org.eclipse.core.internal.compatibility.PluginActivator.start(PluginActivator
> .java:48) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext$1.run(BundleContext.ja
> va:1054) [diagram] at java.security.AccessController.doPrivileged1(Native
>  Method) [diagram] at
> java.security.AccessController.doPrivileged(AccessController.java:350)
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1050) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at java.lang.ClassLoader.defineClass0(Native Method)
> [diagram] at java.lang.ClassLoader.defineClass(ClassLoader.java(Compiled
> Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.defineC
> lass(DefaultClassLoader.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.defineClass(EclipseClassL
> oader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findCla
> ssImpl(DefaultClassLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findCla
> ss(DefaultClassLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.findLocalClass(BundleCla
> ssLoader.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.loadClass(BundleLoader.
> java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java
> (Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.loadClass(Bundle.java(Compile
> d Code))
> [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.internalDoPluginActivation
> (PluginDescriptor.java:471) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.doPluginActivation(PluginD
> escriptor.java:438) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.getPlugin(PluginDescriptor
> .java:406) [diagram] at
> org.eclipse.core.internal.compatibility.PluginActivator.start(PluginActivator
> .java:48) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext$1.run(BundleContext.ja
> va:1054) [diagram] at java.security.AccessController.doPrivileged1(Native
>  Method) [diagram] at
> java.security.AccessController.doPrivileged(AccessController.java:350)
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1050) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at someplugin.someOperation.<init>(someOperation.java:47)
> [diagram] at someplugin.CustomTask.execute(Unknown Source)
> [diagram] at
> org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
> [diagram] at org.apache.tools.ant.Task.perform(Task.java:401)
> [diagram] at org.apache.tools.ant.Target.execute(Target.java:338)
> [diagram] at org.apache.tools.ant.Target.performTasks(Target.java:365)
> [diagram] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
> [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:661) [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:438) [diagram] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
>  Method) [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:84)
> [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> [diagram] at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.
> java(Compiled Code))
> [diagram] at java.lang.reflect.Method.invoke(Method.java(Compiled
Code))
> [diagram] at org.eclipse.ant.core.AntRunner.run(AntRunner.java:342)
> [diagram] at
> org.eclipse.ant.internal.ui.launchConfigurations.AntLaunchDelegate.launch(Ant
> LaunchDelegate.java:225) [diagram] at
> org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguratio
> n.java:157) [diagram] at
> org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java
> :778) [diagram] at
> org.eclipse.debug.ui.DebugUITools.buildAndLaunch(DebugUITools.java:628)
> [diagram] at org.eclipse.debug.ui.DebugUITools$2.run(DebugUITools.java:536)
> [diagram] at
> org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.
> java:101) [diagram] Caused by:
> org.eclipse.jface.util.Assert$AssertionFailedException: null argument;
> [diagram] at org.eclipse.jface.util.Assert.isNotNull(Assert.java:139)
> [diagram] at org.eclipse.jface.util.Assert.isNotNull(Assert.java:116)
> [diagram] at
> org.eclipse.jface.resource.ImageRegistry.<init>(ImageRegistry.java:66)
> [diagram] at
> org.eclipse.jface.resource.ImageRegistry.<init>(ImageRegistry.java:58)
> <Some custom plugin resource manager stuff here>
> [diagram] org.osgi.framework.BundleException: Exception in
> org.eclipse.core.internal.compatibility.PluginActivator.start()
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1071) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at someplugin.someOperation.<init>(someOperation.java:47)
> [diagram] at someplugin.CustomTask.execute(Unknown Source)
> [diagram] at
> org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
> [diagram] at org.apache.tools.ant.Task.perform(Task.java:401)
> [diagram] at org.apache.tools.ant.Target.execute(Target.java:338)
> [diagram] at org.apache.tools.ant.Target.performTasks(Target.java:365)
> [diagram] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
> [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:661) [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:438) [diagram] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
>  Method) [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:84)
> [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> [diagram] at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.
> java(Compiled Code))
> [diagram] at java.lang.reflect.Method.invoke(Method.java(Compiled
Code))
> [diagram] at org.eclipse.ant.core.AntRunner.run(AntRunner.java:342)
> [diagram] at
> org.eclipse.ant.internal.ui.launchConfigurations.AntLaunchDelegate.launch(Ant
> LaunchDelegate.java:225) [diagram] at
> org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguratio
> n.java:157) [diagram] at
> org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java
> :778) [diagram] at
> org.eclipse.debug.ui.DebugUITools.buildAndLaunch(DebugUITools.java:628)
> [diagram] at org.eclipse.debug.ui.DebugUITools$2.run(DebugUITools.java:536)
> [diagram] at
> org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.
> java:101) [diagram] java.lang.NoClassDefFoundError:
> com/ibm/xtools/common/ui/internal/plugin/XToolsUIPlugin
> [diagram] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
> Method)
> [diagram] at
> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccess
> orImpl.java:79) [diagram] at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstruct
> orAccessorImpl.java(Compiled Code))
> [diagram] at
> java.lang.reflect.Constructor.newInstance(Constructor.java(Compiled
Code))
> [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.internalDoPluginActivation
> (PluginDescriptor.java:488) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.doPluginActivation(PluginD
> escriptor.java:438) [diagram] at
> org.eclipse.core.internal.plugins.PluginDescriptor.getPlugin(PluginDescriptor
> .java:406) [diagram] at
> org.eclipse.core.internal.compatibility.PluginActivator.start(PluginActivator
> .java:48) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext$1.run(BundleContext.ja
> va:1054) [diagram] at java.security.AccessController.doPrivileged1(Native
>  Method) [diagram] at
> java.security.AccessController.doPrivileged(AccessController.java:350)
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.startActivator(BundleC
> ontext.java:1050) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleContext.start(BundleContext.ja
> va:991) [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.ja
> va:403) [diagram] at
> org.eclipse.osgi.framework.internal.core.Bundle.start(Bundle.java:312)
> [diagram] at
> org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseCla
> ssLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLo
> ader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.requireClass(BundleLoad
> er.java(Inlined Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findRequiredClass(Bundl
> eLoader.java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.
> java(Compiled Code))
> [diagram] at
> org.eclipse.osgi.framework.adaptor.BundleClassLoader.loadClass(BundleClassLoa
> der.java(Compiled Code))
> [diagram] at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled
> Code))
> [diagram] at someplugin.someOperation.<init>(someOperation.java:47)
> [diagram] at someplugin.CustomTask.execute(Unknown Source)
> [diagram] at
> org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
> [diagram] at org.apache.tools.ant.Task.perform(Task.java:401)
> [diagram] at org.apache.tools.ant.Target.execute(Target.java:338)
> [diagram] at org.apache.tools.ant.Target.performTasks(Target.java:365)
> [diagram] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
> [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:661) [diagram] at
> org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.jav
> a:438) [diagram] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
>  Method) [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:84)
> [diagram] at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> [diagram] at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.
> java(Compiled Code))
> [diagram] at java.lang.reflect.Method.invoke(Method.java(Compiled
Code))
> [diagram] at org.eclipse.ant.core.AntRunner.run(AntRunner.java:342)
> [diagram] at
> org.eclipse.ant.internal.ui.launchConfigurations.AntLaunchDelegate.launch(Ant
> LaunchDelegate.java:225) [diagram] at
> org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguratio
> n.java:157) [diagram] at
> org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java
> :778) [diagram] at
> org.eclipse.debug.ui.DebugUITools.buildAndLaunch(DebugUITools.java:628)
> [diagram] at org.eclipse.debug.ui.DebugUITools$2.run(DebugUITools.java:536)
> [diagram] at
> org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.
> java:101) BUILD FAILED: java.lang.NullPointerException
> 
> Is the result of something that I am doing or is it the new OSGi framework
> in eclipse.