The implementation is divided into two layers. The high-level layer is written in Java and implements JOB interfaces. The implementation is contained in a JAR file (job.jar) which you must add to your CLASSPATH environment variable.
The low-level layer is the kernel implementation, providing for secondary access paths, for persistent storage and for transaction management. The kernel is included in a shared library, written in C (job.dll on Windows platforms, libjob.so on UNIX platforms). It is loaded by the VM when an application creates the first JOB factory instance. It must be found through Java system property java.library.path .