Strange befaviour of spring transaction support for JPA + Hibernate +@Transactional annotation
- by abovesun
I found out really strange behavior on relatively simple use case, probably I can't understand it because of not deep knowledges of spring @Transactional nature, but this is quite interesting.
I have simple User dao that extends spring JpaDaoSupport class and contains standard save method:
@Transactional
public User save(User user) {
getJpaTemplate().persist(user);
return user;
}
If was working fine until I've add new method to same class: User getSuperUser(), this method should return user with isAdmin == true, and if there is no super user in db, method should create one. Thats how it was looking like:
public User createSuperUser() {
User admin = null;
try {
admin = (User) getJpaTemplate().execute(new JpaCallback() {
public Object doInJpa(EntityManager em) throws PersistenceException {
return em.createQuery("select u from UserImpl u where u.admin = true").getSingleResult();
}
});
} catch (EmptyResultDataAccessException ex) {
User admin = new User('login', 'password');
admin.setAdmin(true);
save(admin); // THIS IS THE POINT WHERE STRANGE THING COMING OUT
}
return admin;
}
As you see code is strange forward and I was very confused when found out that no transaction was created and committed on invocation of save(admin) method and no new user wasn't actually created despite @Transactional annotation.
In result we have situation: when save() method invokes from outside of UserDAO class - @Transactional annotation counted and user successfully created, but if save() invokes from inside of other method of the same dao class - @Transactional annotation ignored.
Here how I was change save() method to force it always create transaction.
public User save(User user) {
getJpaTemplate().execute(new JpaCallback() {
public Object doInJpa(EntityManager em) throws PersistenceException {
em.getTransaction().begin();
em.persist(user);
em.getTransaction().commit();
return null;
}
});
return user;
}
As you see I manually invoke begin and commit. Any ideas?
