HyperJAXB3 XJC

JAXB specification introduces a notion of schema compiler.

An XML data-binding facility therefore contains a schema compiler and a schema generator. A schema compiler can consume a schema and generate schema derived classes specific to the schema. [...]

A schema compiler binds components of a source schema to schema-derived Java value classes. Each value class provides access to the content of the corresponding schema component via a set of JavaBeans-style access (i.e., get and set) methods. Binding declarations provides a capability to customize the binding from schema components to Java representation.

JAXB RI accordingly contains a schema compiler called XJC. One of the most important features of XJC is extensibility. You can implement your own XJC plugins to enhance, modify or customize the generated code. See this blog entry for a short introduction.

Hyperjaxb3 takes advantage of this feature and implements an XJC plugin which generates JPA annotations or mappings for schema-derived classes produced by XJC.