Where does the @Transactional annotation belong?

Question

Should you place the `@Transactional` in the `DAO` classes and/or their methods or is it better to annotate the Service classes which are calling using the DAO objects? Or does it make sense to annotate both "layers"?

Answer 1

Since you're talking about services and DAO objects I am assuming all of your business logic lies in the service layer (this may not be the case in Domain Driven Design)

Transactions are best placed where your business logic lies, in your case, it should be in the services.