如何将project配置为android应用程序

在试图解决客户端端点生成问题时，我在项目中勾选了“使用谷歌应用程序引擎”复选框，现在即使我没有勾选，我也会收到错误消息，说“项目……不是web应用程序”

此外，此后我无法保存对项目属性所做的任何更改，它显示“保存项目属性时出错：null”

日志

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我在使用Eclipse 4.3.2.M20140221-1700时遇到了相同的错误消息
解决方案是将“Google插件for Eclipse”更新为版本3.6.0.V2014062229-rel-r43

有趣的是，在Google GWT/App属性中更改多个选项时，我仍然收到了例外。因此，当时的解决方法是alterone属性，即使更改菜单和属性也会导致出现异常

java.lang.NullPointerException
at com.google.appengine.eclipse.core.properties.ui.GaeProjectPropertyPage.saveChangesToAppEngineWebXml(GaeProjectPropertyPage.java:890)
at com.google.appengine.eclipse.core.properties.ui.GaeProjectPropertyPage.saveProjectProperties(GaeProjectPropertyPage.java:336)
at com.google.gdt.eclipse.core.ui.AbstractProjectPropertyPage.performOk(AbstractProjectPropertyPage.java:77)
at org.eclipse.jface.preference.PreferenceDialog$13.run(PreferenceDialog.java:965)
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.preference.PreferenceDialog.okPressed(PreferenceDialog.java:945)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.okPressed(FilteredPreferenceDialog.java:448)
at org.eclipse.jface.preference.PreferenceDialog.buttonPressed(PreferenceDialog.java:233)
at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:628)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
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.jface.window.Window.runEventLoop(Window.java:826)
at org.eclipse.jface.window.Window.open(Window.java:802)
at org.eclipse.ui.dialogs.PropertyDialogAction.run(PropertyDialogAction.java:158)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:499)
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: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)