I forgot the codez...

So I was working with JPA and transactions. Consider the following: In bean 1, with implicit TX 1, managed entities are loaded/created,and returned in bean 2, with implicit TX 2, entities are modified in bean 3, with NO TX, bean 1 is called, and the results are passed to bean 2. and bean 4 is similar to bean 3, but with it's own transaction, TX3 What happens when bean 3 finishes: are the entities updated? What happens when bean 4 finishes, are the entities updated? The answer to this is simple; entities are managed through a persistance context. That context is tied to the transaction. So in bean 2, there is a difference. When called from bean 3, it runs in a different transaction then bean 1, and thus a different persistance context, and thus the entities are not managed 'by this transaction'.When called from bean 4, it all runs in the same transaction, TX3, and the results are persisted.

In spring you can use the @Transactional annotation to marcate public methods as transactions. Any exception thrown in such an exception causes a rollback... Any exception? No, spring only does so on runtime exceptions. Checked exceptions are allowed and do not result in a rollback. And even then, you can allow some transactions to rollback, or not, with the proper properties for the transactions. For examle, @Transactional(rollbackFor="MyCheckedException.class") will rollback for a specific checked exception, and similarly, you can use @Transactional(noRollbackFor="MyUncheckedException.class") for unchecked exceptions. Of course, you might want to make it a little simpler on yourself. This article on stackoverflow shows us a different way: we can use our own transaction handler by overriding spring's. Let's have a sample interface which defines whether an exception should perform a rollback: interface ConfigurableRollback shouldRollbackOnE...