Domain driven design and transactions in Spring environment

Question

I used to design my application around anemic domain model, so I had many repository object, which were injected to the big, fat, transaction-aware service layer. This patte

Answer 1

See this extremely useful blog-post. It explains how to achieve smooth DDD while not loosing Spring's and JPA's capabilities. It is centered around the @Configurable annotation.

My opinion on these matters is a bit non-popular. Anemic data model is actually not wrong. Instead of having one object with data+operations, you have two objects - one with data and one with operations. You can view them as one object - i.e. satisfying DDD, but for the sake of easier use they are physically separated. Logically they are the same.

Yes, this breaks encapsulation, but it doesn't make you use some 'magic' (aop + java agent) in order to achieve your goals.

As for the transactions - there is something called Transaction propagation. Spring supports it with @Transactional(propagation=Propagation.REQUIRED). See this, point 9.5.7. In case you want your transactions to span multiple methods (of multiple objects) you can change the propagation attribute accordingly.

You can also use @Transactional in your service layer, where appropriate, but this might introduce a lot of boilerplace service-classes in cases when you want to use simple, single-step operations like "save".