How to use OpenSessionInViewInterceptor? - spring

Question

Consider entity
public class User {
...
#OneToMany(cascade = CascadeType.ALL)
List<SocialCredential> credentialsList = new ArrayList<SocialCredential> ();
}
with DAO Implementation method
#Transactional
#Override
public User getUser(long id){
Session s = sessionFactory.getCurrentSession();
User u = (User) s.get(User.class, id);
return u;
}
and Controller
#Controller
public class DummyController {
#Autowired
UserDAO userDAO;
public void anyMethodAccessedByGetORPost(){
User u= userDAO.getUser(1L);
}
}
A simple query for entity User automatically fires query to initialize entity list of SocialCredential ? Ultimately it leads to LazyInitializationException.I came to know to know about OpenSessionInViewInterceptor which can solve the issue.How can I apply the same. I am already following http://www.jroller.com/kbaum/entry/orm_lazy_initialization_with_dao but with no success so far.

Answer 1

A simple query for entity User automatically fires query to initialize entity list of SocialCredential ?
It depends on underlying persistence API's default fetch type.
Refer this question
Ultimately it leads to LazyInitializationException -- This is probably you are trying access credentialsList collection after session has been closed.
Replace DAO's getUser(Long id) method with below code may solve LazyInitializationException.
#Transactional
#Override
public User getUser(long id){
Session s = sessionFactory.getCurrentSession();
User u = (User) s.get(User.class, id);
if (u != null) {
u.getCredentialsList(); //it loads the SocialCredentials before session closes.
}
return u;
}