Java Virtual Machine invocation API and others services from the JNI C API

Users of this module and the Java FFI, on desktop computers, must define three environment variables:

• JAVA_HOME points to the installation folder of the target Java VM. This folder should contain the JNI header file include/jni.h. e.g. /usr/lib/jvm/default-java on Debian Jessie.
• JNI_LIB_PATH points to the folder with libjvm.so. e.g. /usr/lib/jvm/default-java/jre/lib/amd64/server/ on Debian Jessie.
• LD_LIBRARY_PATH has the path to the folder with libjvm.so. It's the same value as JNI_LIB_PATH but LD_LIBRARY_PATH is a colon separated list which may contain other paths.

See: http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/jniTOC.html