ejbCreate -permitted and prohibited operations -

[marcus don]

Hi all,
... about permitted and prohibited operations in an ejbCreate
method for a stateful session bean and a stateless session bean.




1) Why I can't mark the current transaction to roll back ?
2) Why I can't Determine whether the transaction has already been marked for rollback?
3) Why I can get a reference to the transaction? (no for stateless)

Thanks

[Roger Chung-Wee]

Why I can't mark the current transaction to roll back ?

ejbCreate never runs in the context of a transaction, so there is nothing to mark for rollback.

Why I can't Determine whether the transaction has already been marked for rollback?

Same reason as above.

Why I can get a reference to the transaction? (no for stateless)

A BMT stateful session bean demarcates its transaction boundaries, and is allowed to do this from ejbCreate. For CMT beans, demarcation is started from the business methods.

[marcus don]

Hi Roger, may you please explain me the meaning of

A BMT stateful session bean demarcates its transaction boundaries

even with an example Thanks!

[Roger Chung-Wee]

The following is not tested code (I've written it here in as hurry), but it does give an indication of how you can do this.

    static DataSource dataSource;
    
    ...
    
    public void go()
    {
        Connection connection = null;
        Context context = null;
        UserTransaction ut = null;
        try
        {
            context = new InitialContext();
            dataSource = (DataSource) context.lookup("....");
            ut = (UserTransaction) context.lookup("....");
            ut.begin(); // begins JTA transaction
            connection = dataSource.getConnection();
            // do updates
            ut.commit(); // ends JTA transaction
        }
        catch (Exception e)
        {
            if (!ut.getStatus() == Status.STATUS_NO_TRANSACTION)
            {
                ut.rollback(); // ends JTA transaction
            }
            // do exception handling
        }
        finally
        {
            // close InitialContext, Connection
        }
    }

[marcus don]

Thank you !