an idea of general service for the persistence context
@Stateless
public class PersistenceContextService {
@PersistenceContext
private EntityManager entityManager;
public void accept(final Consumer<EntityManager> consumer) {
consumer.accept(entityManager);
}
public void accept(final BiConsumer<EntityManager, U> consumer
final U u) {
consumer.accept(entityManager, u);
}
public <R> R apply(final Function<EnityManager, R> function) {
return function.apply(entityManager);
}
public <U, R> R appply(final BiFunction<EntityManager, U, R> function
final U u) {
return function.apply(entityManager, u);
}
}
And now we can do this.
@Path("/people")
public class PeopleResource {
@Inject
private PersistenceContextService service;
@POST
@Consumes({MediaType.APPLICATION_JSON})
public Response create(final Person person) {
service.accept(em -> em.persist(person));
return Response.created(URI.create(person.getId()).build();
}
@GET
@Path("/{id: \\d}")
@Produces({MediaType.APPLICATION_JSON})
public Person read(final long id) {
return service.apply(em -> em.find(Person.class, id));
}
}
