Little bug in SessionFactoryImpl.getCurrentSession()

marco-p · **Posted:** Wed May 18, 2005 6:04 am

In Hibernate 3.0.3 I've found this problem:

Code:

java.lang.NullPointerException
        at org.hibernate.impl.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:511)
...

This happens if there's no current transaction. I think a NPE should be catched for better error handling.

Code:

      Transaction txn = null;
      try {
         txn = transactionManager.getTransaction();
         if ( !JTAHelper.isInProgress( txn.getStatus() ) ) {
-----------------------------------------^
            throw new HibernateException( "Current transaction is not in progress" );
         }
      }
      catch( SystemException se ) {
         throw new HibernateException( "Unable to locate current transaction" );
      }

I'm using the EJB façade pattern, and I've solved setting transaction to Required.

steve · **Posted:** Wed May 18, 2005 9:03 am

Not sure how to make it any more clear than it is in the docs now; a transaction must be in progress in order to use getCurrentSession().

Sure, I can make the error message more explicit if you like.

Maybe I should makethe message have a link to the documentation ;)

marco-p · **Posted:** Wed May 18, 2005 9:31 am

I mean:

Code:

if ( txn == null || !JTAHelper.isInProgress( txn.getStatus() ) ) {

instead of

Code:

if ( !JTAHelper.isInProgress( txn.getStatus() ) ) {

The message is clear enough, if it is displayed !

binz · **Joined:** Wed May 18, 2005 11:29 am **Posts:** 1

i have a mbean loading during jboss startup that calls a session ejb and when i use getCurrentSession() it throws the same null error. the same ejb call works fine after jboss finishes booting. i figure its some dependency issue.

my session bean transaction = 'required'

and the dep on the mbean are:
<depends>jboss:service=proxyFactory,target=ClientUserTransactionFactory</depends>
<depends>jboss:service=proxyFactory,target=ClientUserTransaction</depends>
<depends>jboss:service=TransactionManager</depends>
<depends>jboss:service=ClientUserTransaction</depends>

thanks

marco-p · **Posted:** Wed May 18, 2005 12:15 pm

Just a hint: MBean use the current thread for enqueueing and a different thread for execution, so the current transaction (if created using UserTransaction.begin(), that binds it to current thread) is not available.
Check the documentation for this, I cant say for sure...

steve · **Posted:** Thu May 19, 2005 7:30 pm

jdoe7890 · **Joined:** Sat Jul 24, 2004 10:10 am **Posts:** 15

Can I use the getCurrentSession() in a stateless EJB where the method transaction attribute has been declared as 'NotSupported'.

gavin · **Posted:** Tue May 24, 2005 10:40 am

jdoe7890 · **Joined:** Sat Jul 24, 2004 10:10 am **Posts:** 15

gavin wrote:

No.

Any soultions? I want to make calls to getCurrentSession in my EJB's as transparent as possible. If the method does not support transaction what are my options to get a session ? IMHO , getCurrentSession should return a session even in a method where the transaction Attribute is 'NotSupported'.

marco-p · **Posted:** Wed May 25, 2005 12:15 pm

Why you don't want transaction? What's wrong with it?

gavin · **Posted:** Wed May 25, 2005 12:24 pm

Um. *Think* about what you are asking for!

What should be the scope of the "current" session when there is no transaction?????

Outside of a transaction, the only scope that makes sense is per-operation. So use openSession()/close(). What would you want to use getCurrentSession() for??

marco-p · **Posted:** Wed May 25, 2005 12:28 pm

In a servlet environment, another interesting scope is the servlet request.
That's to say:
- create the session and store it as a request attribute
- flush & close it in a filter, after the servlet execution.

jdoe7890 · **Joined:** Sat Jul 24, 2004 10:10 am **Posts:** 15

gavin wrote:

Um. *Think* about what you are asking for!

What should be the scope of the "current" session when there is no transaction?????

Outside of a transaction, the only scope that makes sense is per-operation. So use openSession()/close(). What would you want to use getCurrentSession() for??

Exactly, the scope will be per-operation. With auto close and auto flush features in Hibernate 3.0.2 and above , my understanding is I will always use getCurrentSession() in all my methods . If there is no transaction defined , Hibernate will return a new session.

tien · **Posted:** Fri May 27, 2005 4:34 pm

A related question...and I apologize if this has been posted. This topic is the closest I could find after performing a search.

I am currently using getCurrentSession() in Hibernate 3.0.5 on JBoss 4.0.2 with session facades.

My understanding is the Sessionobjects returned by getCurrentSession()would have the auto-close attribute set to true. But if I don't explicitly close the Session, I get this message from JBoss:

14:01:43,261 INFO [CachedConnectionManager] Closing a connection for you. Please close them yourself: org.jboss.resource.adapter.jdbc.WrappedConnection@bbddbf

Does anyone know what I am missing here? Or is this the normal behavior? It is kind of a drag if the message is expected. Since this message does pop up a lot and kind of implies the progammer was being sloppy, which is not the impression I would want to give to our customers, who would have access to the logs.

Thanks in advance.

gavin · **Posted:** Sat May 28, 2005 1:23 am

That should not happen if aggressive connection release is working. You should check the log to see that connection is getting closed after each SQL operation.

Note that aggressive connection release requires "help" if you are using scroll() and iterate(). Check the docs.