Eclipse RCP应用程序中的NoClassDefFoundError

时间：2011-11-18 16:25:00

标签： java eclipse eclipse-rcp

在我们的应用程序中，我们有时（大约10次中的10次）在尝试实例化类时获得NoClassDefFoundError。在没有我们的应用程序的情况下打开项目时会发生这种情况。

完整堆栈跟踪如下所示：

!ENTRY org.eclipse.jface 4 2 2011-11-18 12:45:33.941
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
java.lang.NoClassDefFoundError: com.mycompany.products.myapp.gui.model.provider.EMyAppObjectItemProvider
    at com.mycompany.products.myapp.gui.model.provider.MyappguimodelItemProviderAdapterFactory.createMyAppGuiPortAdapter(MyappguimodelItemProviderAdapterFactory.java:159)
    at com.mycompany.products.myapp.gui.model.util.MyappguimodelAdapterFactory$1.caseMyAppGuiPort(MyappguimodelAdapterFactory.java:185)
    at com.mycompany.products.myapp.gui.model.util.MyappguimodelAdapterFactory$1.caseMyAppGuiPort(MyappguimodelAdapterFactory.java:1)
    at com.mycompany.products.myapp.gui.model.util.MyappguimodelSwitch.doSwitch(MyappguimodelSwitch.java:226)
    at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:59)
    at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:75)
    at com.mycompany.products.myapp.gui.model.util.MyappguimodelAdapterFactory.createAdapter(MyappguimodelAdapterFactory.java:462)
    at org.eclipse.emf.common.notify.impl.AdapterFactoryImpl.createAdapter(AdapterFactoryImpl.java:133)
    at org.eclipse.emf.common.notify.impl.AdapterFactoryImpl.adaptNew(AdapterFactoryImpl.java:107)
    at org.eclipse.emf.common.notify.impl.AdapterFactoryImpl.adapt(AdapterFactoryImpl.java:93)
    at com.mycompany.products.myapp.gui.model.provider.MyappguimodelItemProviderAdapterFactory.adapt(MyappguimodelItemProviderAdapterFactory.java:1127)
    at org.eclipse.emf.edit.provider.ComposedAdapterFactory.adapt(ComposedAdapterFactory.java:300)
    at org.eclipse.emf.edit.provider.ComposedAdapterFactory.adapt(ComposedAdapterFactory.java:277)
    at org.eclipse.emf.edit.provider.ComposedAdapterFactory.adapt(ComposedAdapterFactory.java:264)
    at org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider.getColumnText(AdapterFactoryLabelProvider.java:496)
    at org.eclipse.jface.viewers.TableColumnViewerLabelProvider.update(TableColumnViewerLabelProvider.java:70)
    at org.eclipse.jface.viewers.ViewerColumn.refresh(ViewerColumn.java:152)
    at org.eclipse.jface.viewers.AbstractTableViewer.doUpdateItem(AbstractTableViewer.java:399)
    at org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run(StructuredViewer.java:485)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
    at org.eclipse.jface.viewers.StructuredViewer.updateItem(StructuredViewer.java:2167)
    at org.eclipse.jface.viewers.AbstractTableViewer.createItem(AbstractTableViewer.java:277)
    at org.eclipse.jface.viewers.AbstractTableViewer.internalRefreshAll(AbstractTableViewer.java:757)
    at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:649)
    at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:636)
    at org.eclipse.jface.viewers.AbstractTableViewer$2.run(AbstractTableViewer.java:592)
    at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1443)
    at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1404)
    at org.eclipse.jface.viewers.AbstractTableViewer.inputChanged(AbstractTableViewer.java:590)
    at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:280)
    at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:1690)
    at com.mycompany.products.myapp.gui.views.port.composites.Ipv4PortComposite.projectOpenedOrClosed(Ipv4PortComposite.java:732)
    at com.mycompany.products.myapp.gui.project.MyAppResourceController.tellOpenCloseListeners(MyAppResourceController.java:186)
    at com.mycompany.products.myapp.gui.actions.project.MyAppGuiResourceController.openProject(MyAppGuiResourceController.java:266)
    at com.mycompany.products.myapp.gui.project.MyAppResourceController.open(MyAppResourceController.java:592)
    at com.mycompany.products.myapp.gui.project.MyAppResourceController.openWithoutUpdating(MyAppResourceController.java:612)
    at com.mycompany.products.myapp.gui.actions.file.MyAppRecentProjectAction.run(MyAppRecentProjectAction.java:55)
    at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
    at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
        at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
    at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3588)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3209)
    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 com.mycompany.products.myapp.gui.MyAppApplication.start(MyAppApplication.java:175)
    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:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    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.M

这些相关问题没有回答我的问题：

从我读过的内容中，当在运行时类路径中找不到类时会发生此异常。所以我认为如果我可以在实际尝试实例化之前打印运行时搜索路径会很有用。这样我可以检查它失败的1/10是否有任何差异。但是，我还没有找到如何获取运行时搜索路径列表。关于如何获得它们的任何提示？

任何人都可以帮我解决这个问题吗？

3 个答案:

答案 0 :(得分：3)

对于类加载问题，Java提供了一些工具。在Slideshare上查看Do you really get class loaders。我曾经遇到类似Eclipse的帮助系统的问题，我将其集成到 RCP 产品中。在IDE中启动时，一切正常，但在启动导出的产品时，帮助系统无法启动。

答案 1 :(得分：1)

启动应用程序时是否收到此信息？这听起来有些捆绑包在那时尚未初始化。 OSGi将基于依赖项启动模块，但是当您没有设置适当的依赖项时，会有一个随机元素。我建议看那个。如果您想了解更多信息，可以使用OSGi控制台检查您的环境：

http://www.ibm.com/developerworks/library/os-ecl-osgiconsole/index.html

希望这有帮助。

答案 2 :(得分：1)

尝试在启用了OSGi控制台的调试器中运行您的应用程序（-console）。为NoClassDefFoundError添加一个类断点，或者在有问题的代码行（MyappguimodelItemProviderAdapterFactory.java:159）上添加一个类断点。

并且，当断点被击中时：

  • 找到包含MyappguimodelItemProviderAdapterFactory的包的包ID - 例如使用ss OSGi命令
  • 使用bundle <id> OSGi命令
    • 查找捆绑包的完整状态
  • 检查相关软件包 - com.mycompany.products.myapp.gui.model.provider - 是否在“导入的软件包”部分中正确连接

我不知道什么是错的，但你应该检查

  • 已设置正确的包布线 - 可能使用packages com.mycompany.products.myapp.gui.model.provider OSGi命令查找所有提供商
  • 包含EMyAppObjectItemProvider的包实际上包含了类 - 您可以使用status OSGi命令找到OSGi使用的jar（不要假设您知道： - ））
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