Apache Cayenne

Apache Cayenne is an open source persistence framework licensed under the Apache License, providing object-relational mapping (ORM) and remoting services. Cayenne binds one or more database schemas directly to Java objects, managing atomic commit and rollbacks, SQL generation, joins, sequences, and more. With Cayenne's Remote Object Persistence, those Java objects can even be persisted out to clients via Web Services. Or, with native XML serialization, objects can be further persisted to non-Java clients—such as an Ajax-capable browser.