Java™ How To Program (Early Objects), Tenth Edition

29.2.3 The javax.persistence Package

The package javax.persistence contains the JPA interfaces and classes used to interact with the databases in this chapter.

EntityManager Interface

An object that implements the EntityManager interface manages the interactions between the program and the database. In Sections 29.3–29.4, you’ll use an EntityManager to create query objects that you can use to obtain entities from the books database. Section 29.5 you’ll use an EntityManager to both query the addressbook database and to create transactions for inserting new entities into the database.

EntityManagerFactory Interface and the Persistence Class

To obtain an EntityManager for a given database, you’ll use an object that implements the EntityManagerFactory ...