title: Spring bean scoping
body: <p>I've been googling and I just realized something really odd (at least to me). apparently it's recommended to set spring objects as singletons. I have several questions: </p>
  
  <ol>
  <li>logically, it would affect performance right? if 100 users (total exaggeration) are using the same @service objects, wouldn't that mean the other 99 must queue in line to get that @service? (thus, performance issue) </li>
  <li>what if by some diabolical design, those spring objects have states (synchronization problem)? This usually happens with ORM since the BaseDAOImpl usually have protected injected sessionfactory </li>
  <li>speaking of injected sessionfactory, I thought annotations are not inherited? could somebody give explanation about this? 
  thanks</li>
  </ol>