jackrabbit-ocm
This Jackrabbit subproject is an object/JCR persistence and
query service. This tools lets you to persist java objects into
a JCR compliant repository - including association, inheritance,
polymorphism, composition, and the Java collections framework.
Furthermore, this jcr-mapping allows you to express queries in
Java-based Criteria, as well as in JCR query language. It offers
also features like version support and object locking.