Java Reference
In-Depth Information
Listing 10.2.
ItemManager
using an application-managed
EntityManager
The code in this listing is straightforward. First, an
EntityManagerFactory
is injec-
ted . You create an
EntityManager
using the injected
EntityManagerFactory
after the bean is constructed and lose it before the bean is destroyed. This mirrors
what the container does automatically with a container-managed
EntityManager
.
The
EntityManagerFactory
annotation is defined as follows:
@Target({TYPE, METHOD, FIELD})
@Retention(RUNTIME)
public @interface PersistenceUnit {
String name() default "";
String unitName() default "";
}
The
name
and
unitName
elements serve exactly the same purpose as they do for the
@PersistenceContext
annotation. Whereas the
name
element can be used to point
to the JNDI name of the
EntityManagerFactory
, the
unitName
element is used to
specify the name of the underlying persistence unit.
