Folks,
I am working on an android application where I need a third party .so library. I built this third party library (with ndk-build) as per their instructions and
The "No JNI_OnLoad" message is just a warning. JNI_OnLoad is an optional initialization hook.
I guess your problem is inside the openFile() method. Try commenting out the call from Java and see how far you get.
I have a blog post about JNI and some sample code at http://guycole.blogspot.com/2012/03/yet-another-android-ndk-blog-posting.html - perhaps you will find it useful.
Good luck.