Spring's JdbcTemplate and Transactions

Question

When using JdbcTemplate, do I need to explicitly configure transactions?

My code layout looks like the following:

I will have a UserDao that will be injected into my UserService, and then my Controllers will make calls on methods in my UserService.

I want to keep things as simple as possible transaction wise, and I don't need multiple database calls to span a transaction.

By default, do I have to do anything in my configuration file or use a @Transaction annotation anywhere?

Now say in my controller I need to make 2 calls on my userService and accountService, could I explicitly wrap it in a transaction somehow?

userService.updateUser(user);
accountService.updateXXX(...);

Answer 1

Yes, JdbcTemplate is not a substitute for transaction management. You still benefit from database transactions, so userService.updateUser will operate in a database transaction, but if accountService.updateXXX fails, userService.updateUser will not rollback.

If you don't want to use AOP, you can use TransactionTemplate instead. See programmatic transaction management in the Spring Reference Documentation.

One pattern I've seen before is for the MVC controller class to invoke a business service, which encapsulates the operation. The method of the business class could then be annotated @Transactional.

Answer 2

If your controller wants to do several things with users and accounts and have all that happen within one transaction, then you should have a service with one method that does all that stuff. Creating one service per DAO is not a great idea, because you end up with do-nothing wrappers around DAOs and processing will be slow because the database will have to create a separate transaction for each call to a DAO, you're making it do a lot more work than it should have to.

The service should provide functionality to the controller or whoever else is calling it. I try to create services with the idea that the service provides specific functions useful to a certain type of user.