Activity_main.xml:java.lang.NullPointerException

1. Error description

Eclipse.buildid=4.4.0.i20140606-1215java.version=1.7.0_67java.vendor=oracle CorporationBootLoader constants:os= Win32, Arch=x86_64, Ws=win32, nl=zh_cnframework arguments:-product org.eclipse.epp.package.jee.productcommand-line Arguments:-os win32-ws win32-arch x86_64-product Org.eclipse.epp.package.jee.productcom.android.ide.eclipse.adtErrorFri June 23:50:22 CST 2015activity_main.xml: Java.lang.NullPointerExceptionjava.lang.NullPointerExceptionat Android.support.v7.internal.widget.ActionBarOverlayLayout.getDecorToolbar (actionbaroverlaylayout.java:599) at Android.support.v7.internal.widget.ActionBarOverlayLayout.pullChildren (actionbaroverlaylayout.java:588) at Android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure (actionbaroverlaylayout.java:359) at Android.view.View.measure (view.java:17547) at Android.view.ViewGroup.measureChildWithMargins (viewgroup.java:5535 ) at Android.widget.LinearLayout.measureChildBeforeLayout (linearlayout.java:1436) at Android.widget.LinearLayout.Measurevertical (linearlayout.java:722) at Android.widget.LinearLayout.onMeasure (linearlayout.java:613) at Android.view.View.measure (view.java:17547) at android.widget.LinearLayout.measureVertical (linearlayout.java:875) At Android.widget.LinearLayout.onMeasure (linearlayout.java:613) at Android.view.View.measure (view.java:17547) at Com.android.layoutlib.bridge.impl.RenderSessionImpl.measureView (rendersessionimpl.java:640) at Com.android.layoutlib.bridge.impl.RenderSessionImpl.render (rendersessionimpl.java:540) at Com.android.layoutlib.bridge.Bridge.createSession (bridge.java:323) at Com.android.ide.common.rendering.LayoutLibrary.createSession (layoutlibrary.java:349) at Com.android.ide.eclipse.adt.internal.editors.layout.gle2.RenderService.createRenderSession (Renderservice.java : 519) at Com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge ( graphicaleditorpart.java:1584) at Com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayouT (graphicaleditorpart.java:1309) at Com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated ( graphicaleditorpart.java:1066) at Com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditorDelegate.delegatePageChange ( layouteditordelegate.java:686) at Com.android.ide.eclipse.adt.internal.editors.common.CommonXmlEditor.pageChange (commonxmleditor.java:360) at Org.eclipse.ui.part.MultiPageEditorPart.setActivePage (Multipageeditorpart.java : 1101) at Org.eclipse.ui.forms.editor.FormEditor.setActivePage (formeditor.java:607) at Com.android.ide.eclipse.adt.internal.editors.AndroidXmlEditor.selectDefaultPage (androidxmleditor.java:450) at Com.android.ide.eclipse.adt.internal.editors.AndroidXmlEditor.addPages (androidxmleditor.java:311) at Com.android.ide.eclipse.adt.internal.editors.common.CommonXmlEditor.addPages (commonxmleditor.java:285) at Org.eclipse.ui.forms.editor.FormEditor.createPages (formeditor.java:138) at Org.eclipse.ui.part.MultiPageEditorPart.createPartControl (Multipageeditorpart.java:362) at Org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl ( compatibilitypart.java:140) at Org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPartControl ( compatibilityeditor.java:99) at Org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create ( compatibilitypart.java:321) 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:606) at Org.eclipse.e4.core.internal.di.MethodRequestor.execute ( methodrequestor.java:55) at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated (injectorimpl.java:888) At org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated (injectorimpl.java:869) at Org.eclipse.e4.core.internal.di.InjectorImpl.inject (injectorimpl.java:120) at Org.eclipse.e4.core.internal.di.InjectorImpl. Internalmake (injectorimpl.java:337) at Org.eclipse.e4.core.internal.di.InjectorImpl.make (injectorimpl.java:258) At Org.eclipse.e4.core.contexts.ContextInjectionFactory.make (contextinjectionfactory.java:162) at Org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle ( REFLECTIONCONTRIBUTIONFACTORY.JAVA:104) at Org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate (Reflectioncontributionfactory.java : () at Org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create ( REFLECTIONCONTRIBUTIONFACTORY.JAVA:55) at Org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget (Contributedpartrenderer.java : 127) at Org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget (partrenderingengine.java:983) At Org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui (partrenderingengine.java:662) at Org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui (partrenderingengine.java:766) at Org.eclipse.e4.ui.internal.workbench.swt.partrenderingengine.access$2 (partrenderingengine.java:737) at Org.eclipse.e4.ui.internal.workbench.swt.partrenderingengine$7.run (partrenderingengine.java:731) at Org.eclipse.core.runtime.SafeRunner.run (saferunner.java:42) at Org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui (partrenderingengine.java:715) at Org.eclipse.e4.ui.workbench.renderers.swt.StackRenderer.showTab (stackrenderer.java:1251) at Org.eclipse.e4.ui.workbench.renderers.swt.lazystackrenderer$1.handleevent (lazystackrenderer.java:66) at Org.eclipse.e4.ui.services.internal.events.uieventhandler$1.run (uieventhandler.java:40) at Org.eclipse.swt.widgets.Synchronizer.syncExec (synchronizer.java:187) at Org.eclipse.ui.internal.UISynchronizer.syncExec (uisynchronizer.java:156) at Org.eclipse.swt.widgets.Display.syncExec (display.java:4734) at Org.eclipse.e4.ui.internal.workbench.swt.e4application$1.syncexec (e4application.java:218) at Org.eclipse.e4.ui.services.internal.events.UIEvenThandler.handleevent (uieventhandler.java:36) at Org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent (eventhandlerwrapper.java:197) at Org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent (eventhandlertracker.java:197) at Org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent (eventhandlertracker.java:1) at Org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent (eventmanager.java:230) at Org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous (listenerqueue.java:148) at Org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent (eventadminimpl.java:135) at Org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent (eventadminimpl.java:78) at Org.eclipse.equinox.internal.event.EventComponent.sendEvent (eventcomponent.java:39) at Org.eclipse.e4.ui.services.internal.events.EventBroker.send (eventbroker.java:81) at Org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged (uieventpublisher.java:59) at Org.eclipse.emf.common.Notify.impl.BasicNotifierImpl.eNotify (basicnotifierimpl.java:374) at Org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElement (Elementcontainerimpl.java : 171) at Org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.showElementInWindow (modelserviceimpl.java:488) at Org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop (modelserviceimpl.java:454) at Org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop (partserviceimpl.java:692) at Org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop (partserviceimpl.java:385) at Org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart (partserviceimpl.java:1126) at Org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor (workbenchpage.java:3182) at Org.eclipse.ui.internal.workbenchpage.access$23 (workbenchpage.java:3104) at Org.eclipse.ui.internal.workbenchpage$9.run (workbenchpage.java:3086) at Org.eclipse.swt.custom.BusyIndicator.showWhile (busyindicator.java:70) at Org.eclipse.ui.internal.WorkbenchPage. Openeditor (workbenchpage.java:3081) at Org.eclipse.ui.internal.WorkbenchPage.openEditor (workbenchpage.java:3045 ) at Org.eclipse.ui.internal.WorkbenchPage.openEditor (workbenchpage.java:3035) at Org.eclipse.ui.ide.IDE.openEditor (ide.java:541) at Org.eclipse.ui.ide.IDE.openEditor (ide.java:500) at Org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor (editorutility.java:360) at Org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor (editorutility.java:167) at Org.eclipse.jdt.ui.actions.OpenAction.run (openaction.java:268) at Org.eclipse.jdt.ui.actions.OpenAction.run ( openaction.java:233) at Org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun ( selectiondispatchaction.java:275) at Org.eclipse.jdt.ui.actions.SelectionDispatchAction.run ( selectiondispatchaction.java:251) at Org.eclipse.jdt.internal.ui.packageview.PackageExplorerActionGroup.handleOpen (Packageexploreractiongroup.java : 376) at Org.eclipse.jdt.internal.ui.packageview.packageexplorerpart$4.open (PACKAGEEXPLORERPART.Java:538) at Org.eclipse.ui.openandlinkwitheditorhelper$internallistener.open (openandlinkwitheditorhelper.java:48 ) at Org.eclipse.jface.viewers.structuredviewer$2.run (structuredviewer.java:853) 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.fireOpen (structuredviewer.java:850) at Org.eclipse.jface.viewers.StructuredViewer.handleOpen (structuredviewer.java:1142) at Org.eclipse.jface.viewers.structuredviewer$6.handleopen (structuredviewer.java:1249) at Org.eclipse.jface.util.OpenStrategy.fireOpenEvent (openstrategy.java:278) at Org.eclipse.jface.util.openstrategy.access$2 (openstrategy.java:272) at org.eclipse.jface.util.openstrategy$1. Handleevent (openstrategy.java:313) at Org.eclipse.swt.widgets.EventTable.sendEvent (eventtable.java:84) at Org.eclipse.swt.widgets.Display.sendEvent (display.java:4353) at Org.eclipse.swt.wiDgets. Widget.sendevent (widget.java:1061) at Org.eclipse.swt.widgets.Display.runDeferredEvents (display.java:4172) at Org.eclipse.swt.widgets.Display.readAndDispatch (display.java:3761) 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:382) at Org.eclipse.core.runtime.adaptor.EclipseStarter.run (eclipsestarter.java:236) 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:606) 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)

2. Cause of error

3. Solutions

Activity_main.xml:java.lang.NullPointerException