title: eclipse rcp : class loading problem
body: <p>I have plugin A which depends on Plugin B, I am trying to load a class defined in Plugin B from plugin A. And I am sure the class is in the exported packages. but I got ClassNotFoundException, did I miss any thing ?</p>
  
  <pre><code>page = (IPage) Class.forName(pageClass).newInstance();
  </code></pre>
  
  <p>error messages :</p>
  
  <pre><code>java.lang.ClassNotFoundException: amarsoft.dbmp.credit.web.dataobject.DOListPage
      at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)
      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:429)
      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:417)
      at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:169)
      at amarsoft.rcp.base.widgets.DefaultPageRegistry.findPage(DefaultPageRegistry.java:27)
      at amarsoft.rcp.base.widgets.AbstractPageControler.showPage(AbstractPageControler.java:27)
      at amarsoft.rcp.base.widgets.AbstractPageControler.showPage(AbstractPageControler.java:37)
      at amarsoft.dbmp.function.ui.FunctionListPage$3.linkActivated(FunctionListPage.java:261)
      at org.eclipse.ui.forms.widgets.AbstractHyperlink.handleActivate(AbstractHyperlink.java:233)
      at org.eclipse.ui.forms.widgets.AbstractHyperlink.handleMouseUp(AbstractHyperlink.java:327)
      at org.eclipse.ui.forms.widgets.AbstractHyperlink.access$2(AbstractHyperlink.java:311)
      at org.eclipse.ui.forms.widgets.AbstractHyperlink$4.handleEvent(AbstractHyperlink.java:125)
      at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
      at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
      at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
      at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
      at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
      at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
      at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
      at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
      at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
      at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
      at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
      at amarsoft.adt.rcp.ADTApplication.start(ADTApplication.java:29)
      at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
      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:344)
      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:25)
      at java.lang.reflect.Method.invoke(Method.java:597)
      at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
      at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
      at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
      at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
  </code></pre>