Debug Error: Unable to create ClassLoader....

[chickendavis]

Hi everyone,

I've been struggling with the gwt designer and eclipse for the last day.
I'm experiencing a very strange error which no one else seems to have come across. I've tried many a thing to make it work but to no avail.
I have a GWT app that i'm trying to run in debug mode within eclipse.

Unfortunately, when i setup the debug launch entry within eclipse, i receive the following error at the top of the dialog:

"Unable to create ClassLoader, check that GWT_HOME refences valid GWT installation. See "Error log" for more information."

I get this error while trying to create a new launch item under 'GWT Application' and then setting the project and module to run.
I know for sure that i'm setting the correct project/module because co-workers have theirs setup the same.
I'm pretty sure my GWT_HOME is set properly because my project would not build until i set this in eclipse.
Within eclipse, i went to Window --> Preferences --> Java --> Build Path --> Classpath Variables.
I added a GWT_HOME entry which points to "C:\apps\development\eclipse\plugins\gwt-windows-1.4.61".
After setting this up, my project successfully builds. Yet still, i get the ClassLoader error in the gwt application launch config.

I've spent hours on this so i'm getting pretty frustrated. If anyone knows what i can try to fix this, please let me know.
It is greatly appreciated.

Here is some more information about my current config:

Eclipse v3.3.2 SDK: c:\apps\development\eclipse
GWT v1.4.61: C:\apps\development\eclipse\plugins\gwt-windows-1.4.61
GWT Designer v4.0.0: c:\apps\development\gwt designer
Java JDK v1.5.0_15: C:\Program Files\Java\jdk1.5.0_15

I'm using Eclipse v3.3.2 SDK, GWT v1.4.61, and GWT Designer v4.0.0, Java JDK v1.5.0_15

Here is a dump of my log file after attempting to setup a gwt application launch item:

!SESSION 2008-03-19 13:36:17.492 -----------------------------------------------
eclipse.buildId=M20080221-1800
java.version=1.5.0_15
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Command-line arguments: -os win32 -ws win32 -arch x86

!ENTRY com.swtdesigner 4 4 2008-03-19 13:36:39.255
!MESSAGE Designer [6.6.0.200803181315]: org.apache.commons.lang.exception.NestableError: Can not open file |gwt-dev-windows.jar|

Product: WindowBuilder Unlicensed
Version: 6.6.0.200803181315
Expected: Eclipse 3.3
Actual: Eclipse 3.3.100.v20070530
Actual Eclipse Build Name:
Actual Eclipse Build ID: M20080221-1800
IDE Actual Name: Eclipse SDK
IDE Actual Version: 3.3.3.r33x_r20080129
IDE Actual NL: en_US
Physical Address: 00-1B-77-71-66-F1, HardwareAddress[00-19-B9-81-DF-8E]
Code Gen: Flat Mode, Use Existing, First Assignment, Make Final
Events: Anonymous Class
GWT Home: C:/apps/development/eclipse/plugins/gwt-windows-1.4.61
Platform Product: Eclipse SDK
Platform Version: 3.3.3.r33x_r20080129
OS Name: Windows XP
OS Architecture: x86
OS Version: 5.1

!STACK 0
org.apache.commons.lang.exception.NestableError: org.apache.commons.lang.exception.NestableError: Can not open file |gwt-dev-windows.jar|
at com.swtdesigner.gwt.loader.GWTClassLoaderProvider.<init>(GWTClassLoaderProvider.java:62)
at com.swtdesigner.gwt.launch.MainTab$LaunchComposite.ensureCreateClassLoader(MainTab.java:483)
at com.swtdesigner.gwt.launch.MainTab$LaunchComposite.validate(MainTab.java:318)
at com.swtdesigner.gwt.wizards.model.common.AbstractGWTComposite.validateAll(AbstractGWTComposite.java:37)
at com.swtdesigner.gwt.wizards.model.common.AbstractGWTComposite$1.dialogFieldChanged(AbstractGWTComposite.java:30)
at com.swtdesigner.util.ui.dialogfields.DialogField.dialogFieldChanged(DialogField.java:70)
at com.swtdesigner.util.ui.dialogfields.StringDialogField.doModifyText(StringDialogField.java:139)
at com.swtdesigner.util.ui.dialogfields.StringDialogField.access$000(StringDialogField.java:29)
at com.swtdesigner.util.ui.dialogfields.StringDialogField$1.modifyText(StringDialogField.java:117)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:166)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:962)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:943)
at org.eclipse.swt.widgets.Text.wmCommandChild(Text.java:2366)
at org.eclipse.swt.widgets.Control.WM_COMMAND(Control.java:3801)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3675)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4351)
at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2179)
at org.eclipse.swt.widgets.Text.callWindowProc(Text.java:133)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3760)
at org.eclipse.swt.widgets.Text.windowProc(Text.java:2013)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4351)
at org.eclipse.swt.internal.win32.OS.SetWindowTextW(Native Method)
at org.eclipse.swt.internal.win32.OS.SetWindowText(OS.java:3043)
at org.eclipse.swt.widgets.Text.setText(Text.java:1804)
at com.swtdesigner.util.ui.dialogfields.StringDialogField.setText(StringDialogField.java:172)
at com.swtdesigner.gwt.launch.MainTab$LaunchComposite.chooseModule(MainTab.java:426)
at com.swtdesigner.gwt.launch.MainTab$LaunchComposite.access$300(MainTab.java:78)
at com.swtdesigner.gwt.launch.MainTab$3.changeControlPressed(MainTab.java:121)
at com.swtdesigner.util.ui.dialogfields.StringButtonDialogField.changeControlPressed(StringButtonDialogField.java:56)
at com.swtdesigner.util.ui.dialogfields.StringButtonDialogField$1.widgetSelected(StringButtonDialogField.java:113)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:227)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:820)
at org.eclipse.jface.window.Window.open(Window.java:796)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.open(LaunchConfigurationsDialog.java:1133)
at org.eclipse.debug.ui.DebugUITools$1.run(DebugUITools.java:387)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
at org.eclipse.debug.ui.DebugUITools.openLaunchConfigurationDialogOnGroup(DebugUITools.java:391)
at org.eclipse.debug.ui.DebugUITools.openLaunchConfigurationDialogOnGroup(DebugUITools.java:333)
at org.eclipse.debug.ui.actions.OpenLaunchDialogAction.run(OpenLaunchDialogAction.java:82)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:546)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:490)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:402)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
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:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
at org.eclipse.equinox.launcher.Main.run(Main.java:1173)
Caused by: org.apache.commons.lang.exception.NestableError: Can not open file |gwt-dev-windows.jar|
at com.swtdesigner.gwt.loader.JarFileLoader.<init>(JarFileLoader.java:40)
at com.swtdesigner.gwt.loader.GWTClassLoader.<init>(GWTClassLoader.java:49)
at com.swtdesigner.gwt.loader.GWTClassLoaderProvider.<init>(GWTClassLoaderProvider.java:60)
... 73 more
Caused by: java.io.FileNotFoundException: gwt-dev-windows.jar (The system cannot find the file specified)
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(ZipFile.java:203)
at java.util.jar.JarFile.<init>(JarFile.java:132)
at java.util.jar.JarFile.<init>(JarFile.java:97)
at com.swtdesigner.gwt.loader.JarFileLoader.<init>(JarFileLoader.java:38)
... 75 more

[Eric Clayberg]

It looks like you don't have your GWT path preference set...

[chickendavis]

That was exactly the problem. I was not aware of this setting.
Thanks so much for the help Eric.

[Eric Clayberg]

That was exactly the problem. I was not aware of this setting.
Thanks so much for the help Eric.

I'm glad that worked.