I am occaisionally getting:

net.sf.hibernate.HibernateException: Session is currently disconnected

exceptions. The code works most of the time, but if I repeatedly refresh a page from my web app, the Hibernate code occaisionally throws this exception.

Why does this occur?

Thanks,
Kevin Hooke

What database and JDBC driver are you using?

In my experience this exception is usually caused by either 1) underlying JDBC driver or DB dropping connection (had lots of problems with MySQL) or, 2) connection pooling gone bad.

DB2 8.1 on Windows XP, with the JDBC driver that comes with this version of DB2.

Why is the session disconnected?

After each interaction from the web frontend via a Struts Action interacting with a DAO class wrapping the Hibernate code, I call close on the Session.

I am expecting that each new request from the web client will use a new Session, therefore I am confused as to why Hibernate thinks it is disconnected?

I was having a possibly similar problem a while ago, so put in some code to compensate. I haven't had the problem in a while, but I left the code in just in case. :)

Thanks for that code.

I worked out what was going wrong. I am using a Utils class that creates the Sessions and handles closing etc (similar to the example in the manual).

The Session that was returned from my Utils class I was explicitly closing in my DAO code, rather than calling the closeSession() method on my Utils class to close the session. Therefore next time I called getSession() on my Utils class it was returning the old/previous Session in a closed/disconnected state...

Looks like everything is working pretty well now... looks pretty fast too :-)

Thanks,
Kevin Hooke