myeclipse导出war包时抛出空指针异常

myeclipse导出war包时抛出空指针异常，具体异常的日志情况在项目所在工作区间 我的是E:\myworkspace.metadata.log
打开后 错误日志如下

ENTRY com.genuitec.eclipse.export.wizard 4 0 2015-06-05 11:35:41.050
!MESSAGE An unknown error has occured: class java.lang.NullPointerException
!STACK 0
java.lang.NullPointerException
at com.genuitec.eclipse.ast.deploy.core.Deployment.(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ModuleDeployment.(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.WebDeployment.(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.Deployment.create(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.loadFromPreferences(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.init(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.getDefault(Unknown Source)
at com.genuitec.eclipse.export.wizard.WARExportWizardPage.finish(WARExportWizardPage.java:183)
at com.genuitec.eclipse.export.wizard.WARExportWizard$1.run(WARExportWizard.java:71)
at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:464)
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:372)
at org.eclipse.jface.wizard.WizardDialog.run(WizardDialog.java:1029)
at com.genuitec.eclipse.export.wizard.WARExportWizard.performFinish(WARExportWizard.java:64)
at org.eclipse.jface.wizard.WizardDialog.finishPressed(WizardDialog.java:827)
at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:432)
at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:240)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
at org.eclipse.jface.window.Window.open(Window.java:801)
at org.eclipse.ui.internal.handlers.WizardHandler$Export.executeHandler(WizardHandler.java:101)
at org.eclipse.ui.internal.handlers.WizardHandler.execute(WizardHandler.java:277)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:293)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
at org.eclipse.ui.internal.actions.CommandAction.runWithEvent(CommandAction.java:157)
at org.eclipse.ui.internal.actions.CommandAction.run(CommandAction.java:171)
at org.eclipse.ui.actions.ExportResourcesAction.run(ExportResourcesAction.java:116)
at org.eclipse.ui.actions.BaseSelectionListenerAction.runWithEvent(BaseSelectionListenerAction.java:168)
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:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
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:344)
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:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.genuitec.pulse.eclipse.launcher.Main.main(Main.java:110)
解决办法
1.关闭myeclipse
2.找到 项目所在目录 /.metadata/.plugins/org.eclipse.core.runtime/.settings/com.genuitec.eclipse.ast.deploy.core.prefs
删除
3.重启myeclipse

参考
http://blog.sina.com.cn/s/blog_9ea3a4b70101k112.html