How do I properly do a background thread when using Spring Data and Hibernate?

Question

I\'m building a simple Tomcat webapp that\'s using Spring Data and Hibernate. There\'s one end point that does a lot of work, so I want to offload the work to a background t

Answer 1

Method #1: JPA Entity Manager

In background thread: Inject entity manager or get it from Spring context or pass it as reference:

@PersistenceContext
private EntityManager entityManager;    

Then create a new entity manager, to avoid using a shared one:

EntityManager em = entityManager.getEntityManagerFactory().createEntityManager();

Now you can start transaction and use Spring DAO, Repository, JPA, etc

private void save(EntityManager em) {

    try
    {         
        em.getTransaction().begin();                

        

        em.getTransaction().commit();                        
    }
    catch(Throwable th) {
        em.getTransaction().rollback();
        throw th;
    }        
}

Method #2: JdbcTemplate

In case you need low-level changes or your task is simple enough, you can do it with JDBC and queries manually:

@Autowired
private JdbcTemplate jdbcTemplate;

and then somewhere in your method:

jdbcTemplate.update("update task set `status`=? where id = ?", task.getStatus(), task.getId());

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Side note: I would recommend to stay away from @Transactional unless you use JTA or rely on JpaTransactionManager.