Possible bug when loading dll through JNI

Question

Hi guys,
I have come accross a strange occurance, if anyone can help me out i'd appreciate it lot.
I have written an unmanged (MFC) dll which connects to a managed(.NET) dll.
If I load the MFC dll without using any of the references to the managed dll everything is ok.
But as soon as I include a call to initialize a managed member my java program just exits. Then if i try and run it again it gives me a stack overflow exception.
The dll works absolutely 100% perfectly from other c++ applications (I've called all of its methods via a simple dos program), so it seems that there may be some protective layer that java is wrapping the dll in that isn't letting it make any managed calls.
Has anyone had this problem before or know how to get around it?
Below is the code from the unmanged (MFC) dll
     CNewDLLTestApp();
     void WriteToDevice(int Value);
     char ReadFromDevice();
        // this is the managed call, gcroot lets you call managed code from an unmanged area
     gcroot<JavaIntegrateManagedClass::Class1*>c;In the exposed java functions I initialize the class member c, and then call the regular dll functions.

Answer 1

Sadly that is the complete error message.
I've tried putting the load("DLL") in a try catch block but it never catches it. The debugger output screen just prints StackOverflowException.
The JNI calling code doens't even get invoked at this point.
* Class:     MainInterface
* Method:    WriteToDevice
* Signature: (I)V
JNIEXPORT void JNICALL Java_MainInterface_WriteToDevice
  (JNIEnv *, jobject, jint Value)
     MessageBox( (HWND)NULL,"In java function","Unmanged DLL",MB_OK);
     //theApp.c->WriteToDevice(Value);
}If I put the commented line back in the StackOverflowException occurs. If I leave it out everything is fine.
c is a class within a managed DLL, which in turn links to a managed class.
The layers may seem excessive but I understood it was needed to fool java into thinking it was calling unmanaged code.
What I don't understand is how a standard C++ console application can make the calls no problem, but Java can't. Surely the execution of the dll process should be exactly the same.
Thanks
DRB2k5