Hi - I am experimenting with the transaction handling in Hibernate in conjunction with Container Managed Transactions with EJBs deployed on Websphere 5.0.

I have the following settings in my hibernate.xfg.xml:



I have a session bean that is deployed with Container Managed Transactions, and RequiresNew on the method that calls my DAO which contains my Hibernate code.

When I call session.beginTransaction() in my DAO I get the following exception:


Assuming that the UserTransaction is java:comp/UserTransaction in Webpshere, which I think it is, then what does this mean?

Have I configured this correctly? Is what I am trying to do a valid use of Websphere transactions with Hibernate? How do I get Hibernate transactions to participate in the same transaction that is started by my EJB?

Thanks,
Kevin Hooke

Except that you don't delegate conection retrieval to a WS Datasource, I don't see any pb.

Emmanuel - Can you explain what you mean by this statement - do I need to delegate connection retrieval to a Datasource? If so, how do I do this?

I also need to further understand the relation bewteen Container Managed transactions and Hibernate transactions:

- if a transaction has already been started by a Session Bean with Container Managed Transactions and then I execute some Hibermate code, does it implicitly take part within that same transaction, or do I still need to explicitly call beginTransaction() for the Hibernate code to take part within the same transaction?

On a similar note, if an exception occurs within the Hibernate code and I am within a Container Managed transaction, the EJB transaction will be rolled back. Do I explicitly need to rollback the Hibernate transaction, or will a rollback occur as part of the EJB transaction rollback?

Thanks, Kevin

could you try:
<property name="jta.UserTransaction">
UserTransaction</property>

instead of :
<property name="jta.UserTransaction">
java:comp/UserTransaction
</property>

can you post the result if this works, i am also very interested to see if this works. Unfortunately I get other problems under WSAD 5.1.1 (trial)

Thanks for the suggestion.

I've found out that my original config does actually work, providing a transaction has not already been started by the container. For example, if an Action subclass calls the DAO directly, then the code works as I posted.

If an EJB with container managed transactions calls the DAO while it is already in a transaction, then this config and code fails.

Which leads me to wonder that maybe I don't fully understand the use of Hibernate's transactions yet - I have posted another question regarding this here:

http://forums.hibernate.org/viewtopic.php?t=927303

Check the 3.4 section in the ref guide it show configuration of JDBC call vs Datasource call

You said that the code fails if a container manager transaction is underway. But is there no way to use Hibernate in a J2EE env. while making use if the container managed transactions?
Or the put it in another way. I think the Container Managed Entity Bean are much too complex, but the container managed transactions are great.
Does anyone has small example how to use Hibernate in J2EE env without making explicit calls like transaction.start() transaction.commit() that's something the container should manage.

thank you in advance

Robin - see this post here:
http://forum.hibernate.org/viewtopic.php?t=927303

Hi,

I am having the same problem when beginning a transaction. Also using WebSphere and MySQL.

My call starts in a Session bean and is then delegated to a POJO which is my Persistence Manager. If I remove the transaction code and just use session.flush(), everything works, but if I try to open a transaction I can't find the UserTransaction in JNDI.

I have tried changing my JNDI property to just UserTransaction instead of java:comp/UserTransaction and I get the same error. I have also successfully looked up the java:comp/UserTransaction using the built in JNDI context browser and it is found without problem.

I have read this thread and the one being referenced but am still confused as to what this thread really concluded to be the solution...?

How can I keep the transaction code in my persistence manager for container portability and have it work in WebSphere?

How do I set the JNDI name for jta:UserTransaction in WSAD5.0