我在 Eclipse 上从 SVN 获得了一个新的 Java 项目，只是试图在 Eclipse 的 Project Explorer 窗口中打开该项目并收到此错误：
从插件调用代码时出现问题：
"org.eclipse.jface"。
我该如何解决这个问题？
异常堆栈跟踪：
java.lang.NullPointerException
at org.jboss.ide.eclipse.as.classpath.core.ejb3.EJB3ClasspathContainer.getClasspathEntries(EJB3ClasspathContainer.java:115)
at org.eclipse.jdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2695)
at org.eclipse.jdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2853)
at org.eclipse.jdt.internal.core.JavaProject.getResolvedClasspath(JavaProject.java:1958)
at org.eclipse.jdt.internal.core.PackageFragmentRoot.getRawClasspathEntry(PackageFragmentRoot.java:547)
at org.eclipse.jdt.internal.corext.buildpath.ClasspathModifier.isExcluded(ClasspathModifier.java:485)
at org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage.IncludeToBuildpathAction.canHandle(IncludeToBuildpathAction.java:170)
at org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage.BuildpathModifierAction.selectionChanged(BuildpathModifierAction.java:101)
at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:164)
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.viewers.Viewer.fireSelectionChanged(Viewer.java:162)
at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2188)
at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1211)
at org.eclipse.ui.navigator.CommonViewer.handleSelect(CommonViewer.java:478)
at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1241)
at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:239)
at org.eclipse.jface.util.OpenStrategy.access$4(OpenStrategy.java:233)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:403)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4128)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1457)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1480)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1465)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1270)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3974)
at org.eclipse.swt.widgets.Display.applicationNextEventMatchingMask(Display.java:4875)
at org.eclipse.swt.widgets.Display.applicationProc(Display.java:5226)
at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:220)
at org.eclipse.swt.widgets.Widget.mouseDownSuper(Widget.java:1092)
at org.eclipse.swt.widgets.Tree.mouseDownSuper(Tree.java:2052)
at org.eclipse.swt.widgets.Widget.mouseDown(Widget.java:1084)
at org.eclipse.swt.widgets.Control.mouseDown(Control.java:2528)
at org.eclipse.swt.widgets.Tree.mouseDown(Tree.java:2007)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:5471)
at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:220)
at org.eclipse.swt.widgets.Widget.windowSendEvent(Widget.java:2095)
at org.eclipse.swt.widgets.Shell.windowSendEvent(Shell.java:2253)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:5535)
at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
at org.eclipse.swt.widgets.Display.applicationSendEvent(Display.java:4989)
at org.eclipse.swt.widgets.Display.applicationProc(Display.java:5138)
at org.eclipse.swt.internal.cocoa.OS.objc_msgSend(Native Method)
at org.eclipse.swt.internal.cocoa.NSApplication.sendEvent(NSApplication.java:128)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3610)
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)
会话数据：
eclipse.buildId=M20120208-0800
java.version=1.6.0_37
java.vendor=Apple Inc.
BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
Framework arguments: -product org.eclipse.epp.package.jee.product -keyring /Users/saraiva/.eclipse_keyring -showlocation
Command-line arguments: -os macosx -ws cocoa -arch x86_64 -product org.eclipse.epp.package.jee.product -keyring /Users/saraiva/.eclipse_keyring -showlocation