Layer to use the @Transactional annotation in Spring Data JPA

Question

I am using Spring Data JPA for my application, which has the following layers:

1. Service layer with Interfaces and Implements (annotated @service)
2. CRUD repository layer with Spring Data JPA, together with custom repository implementations
3. Entity layer

I was wondering where exactly is the correct place to put @Transactional. Currently, I have it in the service layer, where the repositories are being used.

Answer 1

Transactions belong to Service layer. For example if you have HotelService, then the code would look like this:

@Service("hotelService")
@Transactional
public class HotelServiceImpl implements HotelService {
    @Autowired
    HotelDao hotelDao;

    // The rest of code omited ...
}

Answer 2

What is the best with @Transactional you have to put it if you have a database access.

See Understanding the Spring Framework's declarative transaction implementation

you simply to annotate your classes with the @Transactional annotation, add the line (<tx:annotation-driven/>) to your configuration, and then expect you to understand how it all works.