Before compiling the Java binding you first need to have the C runtime 
compiled and installed. You also need to find where your jni.h header
is installed. It is part of the Java JDK, but it might be placed
in different places on different platforms. The path to the jni.h 
header should be assigned to the JNI_PATH variable in the beginning
of the Makefile that you will find in the root directory of 
the binding. Once this is done type:

$ make
$ make install