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I am new in Hibernate and JPA and I have problem with this annotation. Could someone explain me in simple words what this annotation actually doing, becouse documentation is hard to understand for me in this case.

EDIT I understand what Persistent Context is, but in code I have for example something like that: 

@Repository
public class AbstractRepository<E extends Identifable> implements IRepository<E> {

private Class<E> clazz;

@PersistenceContext
protected EntityManager em;

And I have problem with what @PersistenceContext doing. Sorry, Maybe I was not specific.

FilipW
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1 Answers1

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A PersistenContext is aware of your DataSource,JPA properties, Entities etc. As already described here: What is Persistence Context? You can use it to do some manual stuff in your repository. Eg. handle transactions. I used it a few times in older projects with horrible designed databases. Normally it should not be necessary. Spring can nearly handle everything if your database is designed well.

Maybe this helps you:

    public void saveMovie() {
    EntityManager em = getEntityManager();

    em.getTransaction().begin();

    Movie movie = new Movie();
    movie.setId(1L);
    movie.setMovieName("The Godfather");
    movie.setReleaseYear(1972);
    movie.setLanguage("English");

    em.persist(movie);
    em.getTransaction().commit();
}

https://www.baeldung.com/the-persistence-layer-with-spring-and-jpa

https://www.baeldung.com/hibernate-entitymanager

If you don't need to do something special you can just define a repository interface without any implementation.

https://www.baeldung.com/spring-data-repositories

DCO
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