How does Hibernate differ from the standard JPA API in Java?

Hibernate is one of the implementations of the JPA (Java Persistence API) specification, but Hibernate also provides additional features beyond the JPA standard.

Main differences:

• Standard vs Implementation: JPA is a standard API for ORM in Java, defining a set of interfaces and annotations. Hibernate is a specific implementation of this standard, as well as an independent ORM framework.

• Additional features: Hibernate offers extended functionalities not available in JPA, such as its own query language HQL, second-level cache, more flexible ID generation strategies, specific data types, and more.

• Configuration and integration: When using JPA, you write code through standard interfaces (EntityManager, etc.), which makes it easier to switch implementations. Hibernate allows using both JPA API and its own API.

Example of using JPA with Hibernate as the provider:

EntityManagerFactory emf = Persistence.createEntityManagerFactory("my-pu");
EntityManager em = emf.createEntityManager();

em.getTransaction().begin();
MyEntity entity = em.find(MyEntity.class, 1L);
em.getTransaction().commit();

em.close();
emf.close();

If you use Hibernate directly, you can leverage additional features, such as HQL:

Session session = sessionFactory.openSession();
List<MyEntity> list = session.createQuery("from MyEntity where status = :status", MyEntity.class)
    .setParameter("status", "ACTIVE")
    .list();
session.close();

Thus, using Hibernate directly provides more control and features, but using JPA ensures portability and standardization of the code.