问题描述

  在使用 Eclipse Clean 项目时报错：An error has occurred. See error log for more details. java.lang.NullPointerException。猜测这应该是由于 Eclipse 没有正常关闭所导致的。

  打开 Eclipse 的日志 \workspace\.metadata\.log 如下：

!ENTRY org.eclipse.jface 4 2 2019-04-25 15:42:06.381

!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".

!STACK 0

java.lang.NullPointerException

	at org.eclipse.jst.jee.ui.internal.navigator.web.WebAppProvider.getImage(WebAppProvider.java:99)

	at org.eclipse.jst.jee.ui.internal.navigator.Web25LabelProvider.getImage(Web25LabelProvider.java:47)

	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.findImage(NavigatorContentServiceLabelProvider.java:197)

	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.getColumnImage(NavigatorContentServiceLabelProvider.java:105)

	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.getImage(NavigatorContentServiceLabelProvider.java:98)

	at org.eclipse.ui.internal.navigator.NavigatorDecoratingLabelProvider$StyledLabelProviderAdapter.getImage(NavigatorDecoratingLabelProvider.java:59)

	at org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.getImage(DelegatingStyledCellLabelProvider.java:195)

	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider.getImage(DecoratingStyledCellLabelProvider.java:173)

	at org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.update(DelegatingStyledCellLabelProvider.java:121)

	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider.update(DecoratingStyledCellLabelProvider.java:136)

	at org.eclipse.jface.viewers.ViewerColumn.refresh(ViewerColumn.java:154)

	at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:949)

	at org.eclipse.jface.viewers.AbstractTreeViewer$UpdateItemSafeRunnable.run(AbstractTreeViewer.java:114)

	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)

	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)

	at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:1029)

	at org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run(StructuredViewer.java:472)

	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)

	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)

	at org.eclipse.jface.viewers.StructuredViewer.updateItem(StructuredViewer.java:2150)

	at org.eclipse.jface.viewers.StructuredViewer.internalUpdate(StructuredViewer.java:2133)

	at org.eclipse.jface.viewers.StructuredViewer.update(StructuredViewer.java:2071)

	at org.eclipse.jface.viewers.ColumnViewer.update(ColumnViewer.java:540)

	at org.eclipse.ui.navigator.CommonViewer.update(CommonViewer.java:535)

	at org.eclipse.jface.viewers.StructuredViewer.update(StructuredViewer.java:2015)

	at org.eclipse.jface.viewers.StructuredViewer.handleLabelProviderChanged(StructuredViewer.java:1182)

	at org.eclipse.ui.navigator.CommonViewer.handleLabelProviderChanged(CommonViewer.java:235)

	at org.eclipse.jface.viewers.ContentViewer$1.labelProviderChanged(ContentViewer.java:99)

	at org.eclipse.jface.viewers.BaseLabelProvider$1.run(BaseLabelProvider.java:72)

	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)

	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)

	at org.eclipse.jface.viewers.BaseLabelProvider.fireLabelProviderChanged(BaseLabelProvider.java:69)

	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider$1.labelProviderChanged(DecoratingStyledCellLabelProvider.java:78)

	at org.eclipse.ui.internal.decorators.DecoratorManager$1.run(DecoratorManager.java:446)

	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

	at org.eclipse.ui.internal.decorators.DecoratorManager.fireListener(DecoratorManager.java:443)

	at org.eclipse.ui.internal.decorators.DecorationScheduler$3.runInUIThread(DecorationScheduler.java:536)

	at org.eclipse.ui.progress.UIJob$1.run(UIJob.java:97)

	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)

	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:136)

	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4147)

	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3764)

	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1151)

	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)

	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032)

	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148)

	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:636)

	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)

	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579)

	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)

	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:135)

	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)

	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)

	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)

	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)

	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)

	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:648)

	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)

	at org.eclipse.equinox.launcher.Main.run(Main.java:1465)

	at org.eclipse.equinox.launcher.Main.main(Main.java:1438)

解决方法

1. 删除当前项目，注意不要把这个勾选上：Delete project contents on disk（cannot be undone）
2. 重新导入项目，Project —> Clean... 一下工程就可以了

• 网上的一些方法

Try so start Eclipse from the console/terminal with the -clean option.

On Windows:

Eclipse.exe -clean

On Linux/Unix:

./eclipse -clean

or if Eclipse is in your PATH

eclipse -clean

This will clear your plug-ins cache, maybe it solves the issue.