What is injection in JPA

Question

public class SeatAllocationService implements Serializable {     
  @Inject   
  EntityManager entityManager; 
  //... 
}

I was reading Ticket-monster.2.1.6.final. This annotation made me confused. Looking up Oracle and google didn't help: According to oracle doc, @inject Identifies injectable constructors, methods, and fields. However, what is injectable constructors?

Maybe you can add section from the docs which is not clear to you. — Aleksandr M, Jan 05 '15 at 17:52

score 0 · Accepted Answer · edited May 23 '17 at 12:29

According to the specifications:

The @Inject annotation defined by the Dependency Injection for Java specification identifies an injected field which is initialized by the container when the bean is instantiated, or an initializer method which is called by the container after the bean is instantiated, with injected parameters.

The @Inject annotation is part of Java Dependency Injection. CDI (Content and Dependency Injection) has been updated voor JavaEE 7 but was allready a part of JavaEE 6. Read documentation about CDI here:

http://docs.oracle.com/javaee/6/tutorial/doc/giwhb.html

For this specific example. The EntityManager should be annotated with @PersistenceContext not with @Inject. Refer to this SO question.

What is injection in JPA

1 Answers1