jni

http://www.cis.upenn.edu/~bcpierce/courses/629/papers/Java-tutorial/native1.1/implementing/index.html

jni specification

http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/jniTOC.html

1BM jni 

http://www.ibm.com/developerworks/java/tutorials/j-jni/j-jni.html