Hibernate session thread safety
No. The entity is attached to the session and contains proxies linked to the session (in order to lazy-load themselves). Doing that would thus use the session from multiple threads. Since the session is not thread-safe, this is not a good idea.
While the entity is transient (i.e. you've just created it with new), it's not attached to the session, Hibernate doesn't know about it, and the entity is a plain old Java object. So no problem doing that.I don't have all the details of your DAO though. If the method of your DAO is supposed to be invoked as part of an existing transaction, that won't work, since the transaction is tied to the current thread.