BUG? @Transactional doesn't work on inherited methods

Question

Hi all,
I have to state an odd behaviour:
I have a DAO interface :
public interface UserDAO
..public User save(User user);
In my application I have to use this UserDAO interface to rebuild the DAO layer with a Toplink database access. The new UserDAO implementation is injected into the original ServiceLayer. The according UserService looks like :
public interface UserService
..public User save(User user);
And the implementation :
public class UserServiceImpl
..protected UserDAO userDAO;
..public User save(User user)
....userDAO.save(user);
..public setUserDAO(UserDAO userDAO)
....this.userDAO = userDAO;
However, until I can save my user objects with Toplink I have to annotade the UserService as transactional. Therefore I would write a new UserService class, exending from the original one, like this :
import org.springframework.transaction.annotation.Transactional;
@Transactional
public class TransactionalUserService extends UserServiceImpl
And thats all, since I can inject my JPA UserDAO into this TransactionalUserService and everything will work right.
--> BUT NO ! In this case nothing happens transactional. It only works, when I rewrite the UserService. Then I have :
@Transactional
public class TransactionalUserService implements UserService
..private UserDAO userDAO;
..public User save(User user)
....userDAO.save(user);
..public setUserDAO(UserDAO userDAO)
....this.userDAO = userDAO;
Now my user objects are stored into the database. But why only in this case and not with inherited methods ?

Answer 1

Spring is the one managing your transactions and @Transactional is a Spring annotation so you might get a quick answer to your question on the Spring Data Access Forum.
That being said, instead of subclassing UserServiceImpl just to add @Transactional you could instead use <tx:advice> in your Spring XML configuration to make UserServiceImpl transactional.
--Shaun