Question about spring transaction propagation

Question

I have a question about spring transaction propagation. If I use @Transactional(propagation = Propagation.REQUIRED) to annotate a method m1. When execu

Answer 1

Propagation.REQUIRED (documented here) will create a new transaction (if none exists for the current thread), or will join an existing transaction (if one exists).

When the method exits, then the transaction will be completed (if entering the method caused a transaction to be created), or will leave the transaction open (if a transaction already existed when the method was entered). In other, words, it's symmetrical, and will leave the thread's transactional state in the same state it was before the method was entered.