The overall idea behind this module is to propose a CDI integration of JPA
allowing to programmatically control its persistence units.
Concretely you will create a persistence unit from a PersistenceUnitBuilder
allowing you to fully configure your unit from CDI context including the datasource:
@ApplicationScoped
public class JpaConfig {
@Produces
public PersistenceUnitInfoBuilder unit(final DataSource ds) {
return new PersistenceUnitInfoBuilder()
.setUnitName("test")
.setDataSource(ds)
.setExcludeUnlistedClasses(true)
.addManagedClazz(User.class)
.addProperty("openjpa.RuntimeUnenhancedClasses", "supported")
.addProperty("openjpa.jdbc.SynchronizeMappings", "buildSchema");
}
}
|
|
if your application uses a single persistence unit this is optional and
a default one will be created if a single DataSource bean is available as Bean<?>.
|
The datasource can be produces as you wish using your own configuration mecanism:
@ApplicationScoped
public class JpaConfig {
@Produces // dbcp2 datasource for instance
@ApplicationScoped
public DataSource dataSource() {
final BasicDataSource source = new BasicDataSource();
source.setDriver(new Driver());
source.setUrl("jdbc:h2:mem:jpaextensiontest");
return source;
}
}
|
|
it is recommanded to ensure the DataSource is normal-scoped to not get surprises in term of behavior.
|
Finally you can inject your entity manager using @Unit. Ensure to
decorate with @Jpa a class/method before using the entity manager to activate
the jpa CDI context:
@ApplicationScoped
@Jpa(transactional = false)
public class JPADao {
@Inject
@Unit(name = "test")
private EntityManager em;
@Jpa // with a resource local transaction
public User save(final User user) {
em.persist(user);
return user;
}
// inherit form class, no tx
public User find(final long id) {
return em.find(User.class, id);
}
}
|
|
this integration is 100% based on RESOURCE_LOCAL units for now.
|
Not that if a bean get injected an EntityManager it gets automatically @Jpa(transactional=true)
so previous bean is equivalent to:
@ApplicationScoped
public class JPADao {
@Inject
@Unit(name = "test")
private EntityManager em;
public User save(final User user) {
em.persist(user);
return user;
}
@Jpa(transactional = false)
public User find(final long id) {
return em.find(User.class, id);
}
}