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

The transactions belong to the Service layer. It's the one that apprehends about units of work and use cases. It's the right case if you have several DAOs injected into a Service that needs to work together in a single transaction. It’s happening because of the Eclipse is to Java 1.5

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