Open Source Persistence Frameworks in Java

O/R Broker is a convenience framework for applications that use JDBC. It allows you to externalize your SQL statements into individual files, for readability and easy manipulation, and it allows declarative mapping from tables to objects. Not just JavaBeans objects, but any arbitrary POJO. This is the strength of O/R Broker compared to other similar persistence tools. It allows the developer to design proper object-oriented classes for persistence, without having to be forced to use JavaBeans only, and it has full support for inheritance hierarchies and circular references. One of the design goal for O/R Broker was simplicity, which means that there are only 4 public classes, and an XML Schema file for validation of the very simple XML configuration file. In short, O/R Broker is a JDBC framework that does not dictate domain class design, whether that be having to conform to the JavaBeans spec, having to extend a superclass or implement an interface, but allows persistence independence and proper object-oriented class design.