所有，我发现 Eclipse IDE 中的默认 html 编辑器没有显示概述的结构。似乎IDE只是将html视为简单文本，所以在我按照https://stackoverflow.com/questions/54868/what-is-the-best-html-editor-for的答案安装了网页编辑器插件之后-eclipse成功，当我打开 html 文件时Web Page Editor，出现错误：
无法打开编辑器：引发了意外的异常。
java.lang.NullPointerException
at org.eclipse.wst.sse.ui.StructuredTextEditor.createModelDependentFields(StructuredTextEditor.java:1305)
at org.eclipse.wst.sse.ui.StructuredTextEditor.update(StructuredTextEditor.java:2836)
at org.eclipse.jst.pagedesigner.editors.HTMLEditor.sash_createAndAddDesignSourcePage(HTMLEditor.java:278)
at org.eclipse.jst.pagedesigner.editors.HTMLEditor.createPages(HTMLEditor.java:439)
at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:357)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:662)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:462)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:286)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2857)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2762)
at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2754)
at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2705)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2701)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2685)
at org.eclipse.ui.actions.OpenWithMenu.openEditor(OpenWithMenu.java:344)
at org.eclipse.ui.actions.OpenWithMenu$2.handleEvent(OpenWithMenu.java:192)
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:3910)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3503)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
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:194)
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:368)
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:601)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)
at org.eclipse.equinox.launcher.Main.main(Main.java:1287)
并且还弹出一个错误说：
Unsupported content type in editor.
To associate file extension with a supported content type,
Please see Content Type Preference Page.
我仍然检查了Content Type Preference Page. 以下是设置。请查看它。
有没有人遇到过这个问题？谢谢。