Hello,
I have implemented persistent session management in my application (using
cookies and session IDs in the database). Everything works fine, but
sometimes I see Hibernate errors "Batch update returned unexpected row
count from update" when committing database changes after setting up a new
session.
It turns out that it happens when user starts a request and then quickly
initiates reload of the same page. So I suppose this is a threading issue
(one thread has already started creating session ID record, then user
interrupts the connection and starts another request while the previous one
hasn't been completed). I have implemented simple synchronization, but not
yet sure if it's done correctly.
So the question is: how do I synchronize method that creates the session?
Currently it's implemented inside my authentication service:
public void setupSessionForUser ( User user ) {
synchronized ( this ) {
user.clearSessions ();
SessionToken newSessionToken = SessionToken.create ();
user.addSessionToken ( newSessionToken );
hibernateSession.save ( newSessionToken );
asm.set ( User.class, (User) hibernateSession.merge ( user ) );
cookies.writeCookieValue ( "authcookiename",
newSessionToken.toString () );
logger.info ( "set up new session {} for {}",
newSessionToken.toString (), user.getEmail () );
}
}
Is that correct to synchronize on *this*? Or should I synchronize on HTTP
Session instance instead?
Thanks in advance.
--
Ilya Obshadko
