JNI Calls to Native Methods No Longer Work: Possible Versioning Issue ?

Question

Hello, all. Just a quick question... is it possible that invoking a method in a JNI-compliant DLL from Java 6 will fail if the DLL's source was compiled against the JNI header files from Java 4 or 5 ? I have a DLL with methods that used to be called successfully (and now fail outright and don't even seem to be getting inside the native method), but it seems that the only thing that could have changed in the environment is the installed JRE. Even stranger, I don't get the hs_err* files anymore to indicate that the JVM crashed. Does anyone know why this might happen ? Thanks !

Answer 1

Cthulhu76 wrote:
Hello, all. Just a quick question... is it possible that invoking a method in a JNI-compliant DLL from Java 6 will fail if the DLL's source was compiled against the JNI header files from Java 4 or 5 ? Solely? No.
You could of course be doing something in the JNI code in terms of working with Java which no longer works. Just as it is at least possible that java code from one version might not work with another.
Correct error checking in the JNI code would at least correctly identify this problem however.
I have a DLL with methods that used to be called successfully (and now fail outright and don't even seem to be getting inside the native method), but it seems that the only thing that could have changed in the environment is the installed JRE.The only thing that you assume changed was the JRE.
You seem unsure whether the JNI is being called at all, so verifying that first would be a good idea.