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JNI callback exception from custom SWT widget [message #452030]

Mon, 14 March 2005 07:40

Chris Saari

Messages: 4
Registered: July 2009

Junior Member

I have a custom SWT widget with a native Win32 implementation across JNI
as per usual. The calls into the C++ from Java work fine, but whenever I
attempt to call back out to Java from C++ I end up with the following
exception being thrown. It looks like another instance of Eclipse is
trying to start, but that make no sense to me, I'm just calling back into
a simple method of the Java object. I've read the "Writing Your Own
Widget" tutorial and no help there; everything looks fine in my code, I
get the methodID, I've got a valid JavaVM* and JNIEnv*, etc. Any help is
appreciated!

Unhandled event loop exception, followed by:
java.lang.NullPointerException
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:14 73)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java :2429)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.jav a:1377)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1348)
at
org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Work bench.java:254)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.j ava:141)
at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplicatio n.java:96)
at
org.eclipse.core.internal.runtime.PlatformActivator$1.run(Pl atformActivator.java:335)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:273)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseS tarter.java:129)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcce ssorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMe thodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.eclipse.core.launcher.Main.basicRun(Main.java:185)
at org.eclipse.core.launcher.Main.run(Main.java:704)
at org.eclipse.core.launcher.Main.main(Main.java:688)

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