Chapter 36

Introduction to Hibernate Framework

In Lesson 33 you got familiar with the Java Persistence API, which is part of Java EE 6. But JPA wasn’t created from scratch. It took many ideas from Hibernate — an open-source object-relational framework started by Gavin King in 2001. Hibernate version 3.5 and above support the JPA 2.0 specification.

The official website of Hibernate is www.hibernate.org, where you can find documentation, code samples, and tools. Plenty of books and online articles are published about this popular framework. I prefer using SQL and JDBC for all data-related processing, but these days knowledge of Hibernate is required in many job postings. That’s why I decided to include this brief overview of Hibernate even though it’s not a part of the Java specification but a third-party framework.

If you are going to use Hibernate for work, consider using the Eclipse plug-ins available at www.hibernate.org/subprojects/tools.html.

The Big Picture

The main idea behind any ORM framework is to replace writing SQL with manipulating the objects. In the Java world, this means putting a layer on top of JDBC that will enable you to simply create a POJO, assign values to its fields, and tell it “Persist yourself in the database.” This is what Hibernate is for.

Proponents of this approach argue that removing the dependency on vendor-specific SQL syntax provides easy switching from one DBMS to another without the need to modify the Java code responsible for querying ...

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