Software Environment:
WinXP
Hibernate2.1.4
jdk1.4.1
eclipse3.0

As we all know, when we use session's close() function, it will run clearup() and disconnect(). But in disconnect(), there exists some codes as follows:

if (connect) {
connect = false;
return null;
}

My confusion : why not set variable connection null ?

I guess for this reason the test codes as follows can run .

Session session = _sessions.openSession();
session.close();

session.beginTransaction();
session.save(Object);

Another Question:

I guess that no one agree on the pattern of "session per operation", but in a Swing application, how can I manage the session and transaction?
As I know, ThreadLocal and Filter can use in Web App. Maybe I can use
Threadlocal in "session per a frame or dialog".

Any idea?

Thanks in advance.

The right way is to use session per transaction for any kind of application.

but how about the granularity of transaction?

In my application, I use the default transaction, namely jdbc transaction.
And the transaction will declared after session is opened.

In the session per transaction , I guess that I have to use JTA.

You need JTA for distributed transactions only, but it is more about implementation. You need to think about transaction demarcation only, it is not a persistence aspect, transaction is conceptual thing ( "unit of work" ), but in implementation it can be same as JDBC transaction. You need to use new session per transaction because session local cache becomes invalid at the end of transaction, transaction must be thread local too, but you can have many transactions in the same thread (It is implementation limitation, but it is not problem)