Java Hibernate（JPA）查询

Question

what is the right way to make a query with JPA. Here is my way now:

EntityManagerFactory factory = Persistence.createEntityManagerFactory("hellojpa");
        EntityManager em = factory.createEntityManager();
        em.getTransaction().begin();

        //query here

        em.getTransaction().commit();
        em.close();

I just started learning it and I am pretty sure that there will be more intelligent way. Some helper class, maybe?

Thanks.

Answer 1

In my opinion it is the right way, if you use local transactions. Keep in mind that EntityManager is not thread safe.

You will have less boilerplate code in a JavaEE environment, where the application server takes care of EntityManager injection and uses JTA.

@PersistenceContect
EntityManager em;

public void foo() {
// query
}