jalopy source code formatter give Unhandled event loop exception when formatting

Question

I have used eclipse Indigo and Juno to set up jalopy according to the jalopy installation guide.My Jalopy version is 1.9.4. I can format the code in Indigo without any problem. But I can't format the code in Juno. In error log view, I can see Unhandled event loop exception in org.eclipse.ui plugin, when I try to format the code in Juno.

this is the relevant exception stack trace

org.eclipse.swt.SWTException: Failed to execute runnable (java.util.ConcurrentModificationException) at org.eclipse.swt.SWT.error(SWT.java:4361) at org.eclipse.swt.SWT.error(SWT.java:4276) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:138) at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4144) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3761) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1022) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:916) at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86) at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:585) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:540) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124) 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:353) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584) at org.eclipse.equinox.launcher.Main.run(Main.java:1438) at org.eclipse.equinox.launcher.Main.main(Main.java:1414) Caused by: java.util.ConcurrentModificationException at com.triemax.EclipsePlugin.l(EclipsePlugin.java) at com.triemax.EclipsePlugin.a(EclipsePlugin.java:74) at com.triemax.nu.run(nu.java:8) at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135) ... 24 more

what is the reason for this exception? how to prevent this?

EDIT :same exception arise in Eclipse Kepler

Answer 1

The version you have is not compatible with Juno or Kepler. A more recent build fixes the problem.