I do quite a few projects which use JNI libraries, and it's a real pain to work with them, because you 
hava to make sure they're on the VM's native library path when you run your app. The easiest solution is 
to put jni libraries in the working directory (at least on OSX), but since often there may be different 
ways of running the app (for instance when running normally, or unit testing) the working directory may 
be different depending how it's run. This is a pain, and means that one ends up copying the same 
libraries into several different places. If you're developing the library at the same time this can lead to 
copies being out of sync with their source and other nightmares.

What I'd like to see in netbeans is a "native library" tab in the Library manager that allows me to specify 
the DLL required for a particular library - whenever the app is run the IDE would then add the DLL to 
the VM's native library path for me. This would be a huge improvement for anyone using jni libraries, 
and it doesn't seem like it would be a lot of work to implement.