作Eclipse插件時遇到錯誤，java.lang.NoClassDefFoundError:

下面的錯誤信息是在Eclipse下開發插件時，用到dom4j-1.6.1.jar時出現的一個錯誤。

假如你已經把dom4j-1.6.1.jar和jaxen-1.1.1.jar放在工程的lib目錄下，並且已經右擊dom4j-1.6.1.jar、jaxen-1.1.1.jar將它們添加到Build Path，仍是出現這樣的錯誤，那麼很肯能你還須要編輯一下META-INF/MANIFEST.MF這個文件，以下圖，在右下角添加jar包，添加之後，Build、MANIFEST.MF、build.properties這三個選顯卡里面的內容也會做出相應的修改，看一下就知道是什麼意思了。之後添加jar包的話，應該都是相似的修改。

 

 

 

org.eclipse.e4.core.di.InjectionException: java.lang.NoClassDefFoundError: org/dom4j/DocumentException
 at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:63)
 at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:243)
 at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:224)
 at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
 at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:167)
 at org.eclipse.core.commands.Command.executeWithChecks(Command.java:499)
 at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
 at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:213)
 at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:850)
 at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.handleWidgetSelection(HandledContributionItem.java:743)
 at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.access$7(HandledContributionItem.java:727)
 at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem$4.handleEvent(HandledContributionItem.java:662)
 at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
 at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
 at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4170)
 at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3759)
 at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
 at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
 at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
 at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:138)
 at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:610)
 at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
 at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
 at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
 at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
 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:354)
 at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636)
 at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
 at org.eclipse.equinox.launcher.Main.run(Main.java:1450)
 at org.eclipse.equinox.launcher.Main.main(Main.java:1426)
Caused by: java.lang.NoClassDefFoundError: org/dom4j/DocumentException
 at myplugin.handlers.SampleHandler.execute(SampleHandler.java:57)
 at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:290)
 at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:90)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56)
 ... 37 more
Caused by: java.lang.ClassNotFoundException: org.dom4j.DocumentException cannot be found by myPlugin_1.0.0.0
 at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:501)
 at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:421)
 at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:412)
 at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 ... 45 more