The Forest Project: PJama: A Prototype Implementation of Orthogonal Persistence for the Java platform

Orthogonal Persistence for the Java platform is characterized by three principles:

• Type orthogonality: All types, including Class, Thread, can be made persistent.
• Persistence independence: No modifications to either the source code or class file are required in order that objects of the associated class can be made persistent.
• Persistence by reachability: The lifetime of an object is determined solely by its reachability from designated (persistent) root objects.

N.B. The current release of PJama does not support persistent Thread instances.

OPJ and PJama are the result of collaborative research between the Forest Project at SunLabs and the Persistence and Distribution research group in the Department of Computing Science at the University of Glasgow, Scotland.

Further Information

• A tutorial on using OPJ.
• The specification of the OPJ API.
• The manual pages for the tools available with PJama.
• Several papers on OPJ and PJama.

The PJama Release