Hi, I found that there may be some minor improvements about annotations in your code. 

By adding @transactional at the class level, many important aspects such as transaction propagation can be handled automatically. It can wrap your service in a generated proxy that joins an active transaction or starts a new one and commits or rolls the transaction back after your methods got executed.

Based on the advantages mentioned above, I recommend that you add the @transactional annotation at the class level.

Hope my suggestions are useful!