jni.h: no such file or directory

You have to add the JDK path to the include path, so the compiler knows the location of the file.

Windows:

/I "$(JAVA_HOME)\include" /I "$(JAVA_HOME)\include\win32"

Linux:

-I"${JAVA_HOME}/include" -I"${JAVA_HOME}/include/linux"

Mac:

-I"${JAVA_HOME}/include" -I"${JAVA_HOME}/include/darwin"