Book.java

@Entity
public class Book {

  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  @Column(name = “id”, updatable = false, nullable = false)
  private Long id;

  @NaturalId
  private String isbn;

  …
}

LoadByNaturalId.java

EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
Session session = em.unwrap(Session.class);

Book b = session.byNaturalId(Book.class).using(Book_.isbn.getName(), “978-0321356680”).load();

LoadByNaturalId.log

06:14:40,705 DEBUG SQL:92 – select book_.id as id1_0_ from Book book_ where book_.isbn=?
06:14:40,715 DEBUG SQL:92 – select book0_.id as id1_0_0_, book0_.isbn as isbn2_0_0_, book0_.publishingDate as publishi3_0_0_, book0_.title as title4_0_0_, book0_.version as version5_0_0_ from Book book0_ where book0_.id=?

LoadBySimpleNaturalId.java

EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
Session session = em.unwrap(Session.class);

Book b = session.bySimpleNaturalId(Book.class).load(“978-0321356680”);

LoadWithLocking.java

EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
Session session = em.unwrap(Session.class);

Book b = session.bySimpleNaturalId(Book.class).with(LockOptions.UPGRADE).load(“978-0321356680”);

LoadWithLocking.log

06:19:34,055 DEBUG SQL:92 – select book_.id as id1_0_ from Book book_ where book_.isbn=?
06:19:34,128 DEBUG SQL:92 – select book0_.id as id1_0_0_, book0_.isbn as isbn2_0_0_, book0_.publishingDate as publishi3_0_0_, book0_.title as title4_0_0_, book0_.version as version5_0_0_ from Book book0_ where book0_.id=? for update

NaturalIdCaching.java

EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
Session session = em.unwrap(Session.class);

session.byId(Book.class).load(1L);
log.info(“Get book by id”);

Book b = session.bySimpleNaturalId(Book.class).load(“978-0321356680”);

NaturalIdCaching.log

06:20:39,767 DEBUG SQL:92 – select book0_.id as id1_0_0_, book0_.isbn as isbn2_0_0_, book0_.publishingDate as publishi3_0_0_, book0_.title as title4_0_0_, book0_.version as version5_0_0_ from Book book0_ where book0_.id=?
06:20:39,785 INFO TestHibernateNaturalId:78 – Read book by id
06:20:39,788 INFO TestHibernateNaturalId:81 – Book title: Effective Java