title: Question about Spring transaction propagation
body: <p>I have a question about Spring <em>transaction propagation</em>.</p>
  <p>Suppose I use <code>@Transactional(propagation = Propagation.REQUIRED)</code> to annotate a method <code>m1()</code>. When execution logic enters <code>m1()</code>, if there is already a transaction, <code>m1()</code> will use that one. When after <code>m1()</code>, what about the transaction? It will end or still remain open? (if I call <code>m1()</code> in another method, and after the invocation there is still other things to do).</p>
  <p>In summary, I want to know <strong>when exiting</strong> an annotated method, the transaction ends or still remains open?</p>
  <p>Great thanks.</p>