Hibernate JPA support

AcrossHibernateJpaModule activates JPA support for the entire Across context. It allows other module to subscribe their entities to the JPA EntityManager represented by the AcrossHibernateJpaModule. The JPA implementation is built on top of Hibernate. The module also activates support for Spring Data JpaRepository implementations and comes with a set of helpers to facilitate repository implementations.

In an Across application with a single entity manager, adding AcrossHibernateJpaModule will serve as a drop-in replacement for the regular Spring Boot JPA starter in the application module.