hi, i am developing a eclipse plugin . In this plugin i am using reflection to execute a function in a class present in another project which is a hibernate project.Whenever the invoke is used i.e mymethod.invoke(myobj);

it is giving this exception

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:599)
    at packagesearch.DummyExecution.execution(DummyExecution.java:154)
    at packagesearch.HelloWorldAction.run(HelloWorldAction.java:48)
    at org.eclipse.ui.internal.PluginAction.runWithEvent(PluginAction.java:251)
    at org.eclipse.ui.internal.WWinPluginAction.runWithEvent(WWinPluginAction.java:229)
    at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:583)
    at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:500)
    at org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:452)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3823)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3422)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2384)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2348)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2200)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:495)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:490)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:193)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:386)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:599)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:549)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1212)
Caused by: java.lang.NoClassDefFoundError: org.dom4j.DocumentException
    at java.lang.J9VMInternals.verifyImpl(Native Method)
    at java.lang.J9VMInternals.verify(J9VMInternals.java:72)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:134)
    at test.Example.demo1(Example.java:38)
    ... 36 more
Caused by: java.lang.ClassNotFoundException: org.dom4j.DocumentException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:419)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:643)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:345)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:609)
    ... 40 more

what is the exact problem . i have used loader to load the class.Help