Just Hibernate

Chapter 8. Java Persistence API

The Java Persistence API (JPA) was developed in order to establish a set of standards for the object-persistence programming world. It was successful in delivering guidelines for ORM persistence providers. Most of the good parts of the JPA specification were derived from Hibernate itself, along with some very well-drawn industry practices, so the specification implementation should not be new to you. The aim of this chapter is to provide you with details about developing JPA-compliant applications using Hibernate.

Standards and specifications make software components easier to port and reuse in disparate environments. They help end users change frameworks without much hassle should they need to do so. The Java community did a good amount of work in enforcing standards by introducing specifications via the Java Community Process (JCP) program.

In the earlier days of the object-relational persistence world, there wasn’t any specification for ORM frameworks. We either had to write our own software or work with a nonstandard third-party product, which locked you into the vendor. Most of these frameworks were not generic and robust enough, in the sense that they polluted the architecture knitting the frameworks to the underlying databases. Whether you wrote your own software or went with one of these vendors, it was a big hassle—and in some cases a major headache—to port to another product or database without embarking on a major re-engineering or restructuring ...