Eclipse - Unable to delete project from workspace. NPE

Question

I unable to delete the project from the workspace. Eclipse throws NPE and I have NFI how to resolve this issue.

java.lang.NullPointerException
    at org.eclipse.ltk.ui.refactoring.resource.DeleteResourcesWizard$DeleteResourcesRefactoringConfigurationPage.createControl(DeleteResourcesWizard.java:89)
    at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.createContents(RefactoringWizardDialog2.java:631)
    at org.eclipse.jface.window.Window.create(Window.java:431)
    at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
    at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation$1.run(RefactoringWizardOpenOperation.java:171)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation.run(RefactoringWizardOpenOperation.java:192)
    at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation.run(RefactoringWizardOpenOperation.java:115)
    at org.eclipse.ltk.internal.ui.refactoring.actions.DeleteResourcesHandler.execute(DeleteResourcesHandler.java:40)
    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.executeCommandInContext(HandlerService.java:270)
    at org.eclipse.ui.internal.ide.actions.LTKLauncher.runCommand(LTKLauncher.java:95)
    at org.eclipse.ui.internal.ide.actions.LTKLauncher.openDeleteWizard(LTKLauncher.java:47)
    at org.eclipse.ui.actions.DeleteResourceAction.run(DeleteResourceAction.java:481)
    at org.eclipse.jdt.internal.ui.refactoring.reorg.DeleteAction.run(DeleteAction.java:162)
    at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:274)
    at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:250)
    at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
    at org.eclipse.jface.commands.ActionHandler.execute(ActionHandler.java:119)
    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.keys.WorkbenchKeyboard.executeCommand(WorkbenchKeyboard.java:468)
    at org.eclipse.ui.internal.keys.WorkbenchKeyboard.press(WorkbenchKeyboard.java:786)
    at org.eclipse.ui.internal.keys.WorkbenchKeyboard.processKeyEvent(WorkbenchKeyboard.java:885)
    at org.eclipse.ui.internal.keys.OutOfOrderListener.handleEvent(OutOfOrderListener.java:76)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1282)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1267)
    at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1294)
    at org.eclipse.swt.widgets.Widget.gtk_key_press_event(Widget.java:730)
    at org.eclipse.swt.widgets.Control.gtk_key_press_event(Control.java:2841)
    at org.eclipse.swt.widgets.Composite.gtk_key_press_event(Composite.java:734)
    at org.eclipse.swt.widgets.Tree.gtk_key_press_event(Tree.java:1977)
    at org.eclipse.swt.widgets.Widget.windowProc(Widget.java:1743)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:4796)
    at org.eclipse.swt.widgets.Tree.windowProc(Tree.java:3485)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4360)
    at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method)
    at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(OS.java:8189)
    at org.eclipse.swt.widgets.Display.eventProc(Display.java:1238)
    at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method)
    at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:2237)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3159)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
    at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
    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:369)
    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:620)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1408)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1384)

and this is my environment :-

eclipse.buildId=M20110210-1200
java.version=1.6.0_21
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=linux, ARCH=x86, WS=gtk, NL=en_AU
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os linux -ws gtk -arch x86 -product 
org.eclipse.epp.package.jee.product

Answer 1

The related Eclipse bug is 345477. In that post, some ia32-libs bugs are referenced. The suggested workaround in that bug is executing the following before executing Eclipse:

export GDK_PIXBUF_MODULE_FILE=/usr/lib32/gdk-pixbuf-2.0/2.10.0/loaders.cache

I can confirm that this works, even with the Ubuntu-Mono-Light icon set. I use Eclipse 32 bit on Java 32 bit on Ubuntu 11.04 64 bit.

Answer 2

I've noticed this same problem using Eclipse 3.6 SR2 on Ubuntu 11.04. It works fine however on Ubuntu 10.04 and Windows 7 using the same version of Eclipse. The NullPointerException is coming from line 89 of DeleteResourcesWizard because image is null:

87    Image image= parent.getDisplay().getSystemImage(SWT.ICON_QUESTION);
88    Label imageLabel = new Label(composite, SWT.NULL);
89    imageLabel.setBackground(image.getBackground());

The quick fix I've found for Ubuntu 11.04 is to use a different theme (like Clearlooks) or icon set (like GNOME). The default theme that doesn't work for me is Ambiance, which defaults to the Ubuntu-Mono-Dark icon set. I guess it must be missing the icon (or it was renamed) needed by SWT.ICON_QUESTION and Eclipse doesn't gracefully deal with not finding it.

Answer 3

The closest bug (issue 302791) was fixed in 3.6 (which I suspect you have, with a build Id M20110210-1200)

Your error seems to take place at the very beginning of the process, since it isn't able to create the `DeleteResourcesWizard.
It could be because of:

• some strange selection (did you try selecting the project in the Package Explorer? in the Resource Explorer?)
• some deleted resources still referenced by the project.

If you can reproduce the problem every time, this can be worth a new Eclipse bug report.

Answer 4

Thanks, I've changed my icon set to GNOME and it worked! Ubuntu 11.04 the worst Ubuntu ever! It seems like Ubuntu is aiming to be like Windows ME and Vista...