Meecrowave

Meecrowave JPA

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);
 }
}

Integration with Bean Validation

The extension will try to find a ValidatorFactory in CDI context and will provide ir to the JPA provider if the ValidationMode is not NONE and a Bean<ValidatorFactory> exists.