Hibernate Xdoclet Mapping transformation to JPA

Hibernateis an open source object relational mapping (ORM) framework for the java-based technologies. Hibernate was started in 2001 before Java language annotations (feature of Java 5) came into existence, this led to a lot of enterprise systems build using Xdoclet, whichprovided a way to specify metadata as comments for Hibernate ORM within the java entity classes. Ant (a build tool) was then used to convert these Xdoclet metadata to generate hibernate mapping files (hbm files) which were then processed by the Hibernate runtime engine. With the advent of Java annotations, Hibernate also created anannotations module to provide a way to use standard java annotations within the entity classes, making the Hibernate Xdoclet annotations obsolete. Based on the community feedback and popularity of ORM based engines, Java Persistence Architecture (JPA) was first released in 2006 to provide a standard way of utilizing ORM products and its annotations. Enterprise systems that might have thousands of entities which still utilize Xdoclet way of managing metadata, have a hard time of moving to JPA as manual transformation can be buggy and expensive and that's where an automated mechanism of transforming java source codebase to not only convert Xdoclet metadata mapping to standard JPA annotations but also move the proprietary use of Hibernate API's to JPA API's across the codebase. If Hibernate engine is used as the JPA provider, one can use Hibernate API where JPA doesn't provide that specific feature.