How to propagate a client-side UserTransaction into a stateless session bean using BMT

Question

This scenario using CMT is working:

Stateless session bean with CMT, one method annotated with @TransactionAttribute(TransactionAttributeType.MANDATORY). Within this method, a record is written into a RDBMS using an XA data source and plain JDBC.
The stand-alone client (separate JVM, command-line Java application) is getting a UserTransaction from the application server (by JNDI lookup), starts the transaction, and calls the EJB.
If the client commits the UserTransaction, the record is written into the database.
If the client rollbacks the UserTransaction, the record is not written into the database.
In the PostgreSql log files, one can see the prepared transaction with BEGIN, and COMMIT or ROLLBACK
If the client does not start a transaction before calling the EJB, a javax.ejb.EJBTransactionRequiredException is thrown (as expected, TransactionAttributeType.MANDATORY).

Now I switch from CMT to BMT

Again, if the client does not start a transaction before calling the EJB, a javax.ejb.EJBTransactionRequiredException is thrown (as expected, TransactionAttributeType.MANDATORY).
If I call sessionContext.getUserTransaction().getStatus(), it always reports Status.STATUS_NO_TRANSACTION.
The record is always written into the database, if the client calls commit or rollback.
In the PostgreSql log files, there are no prepared transactions, just plain insert commands.

The source of the EJB:

@Remote(DemoIfc.class)
@Stateless(name = "DemoBmt")
@TransactionManagement(TransactionManagementType.BEAN)
public class DemoBmt implements DemoIfc {
    @Resource
    private SessionContext sessionContext;

    @TransactionAttribute(TransactionAttributeType.MANDATORY)
    public String ping(final String s) throws SystemException {
        try {
            System.out.println("TX: status: "
                    + this.sessionContext.getUserTransaction().getStatus());
        } catch (Exception e) {
            System.out.println("TX: status: " + e.getMessage());
        }

        try {
            writeIntoDb();
            if (s.startsWith("crash")) {
                throw new SystemException("Simulated crash");
            }
            return s.toUpperCase();
        } catch (NamingException e) {
            throw new SystemException(e.getMessage());
        } catch (SQLException e) {
            throw new SystemException(e.getMessage());
        }
    }
}

The client's source:

final UserTransaction ut = (UserTransaction) initialContext
        .lookup("UserTransaction");
try {
    ut.begin();
    System.out.println(demo.ping("crash: DemoBmt with UT"));
    ut.commit();
} catch (Exception ex) {
    System.out.println("Expected rollback");
    ut.rollback();
}

I am using JBoss 6.0.0 final.

How can I properly propagate the client-side UserTransaction into the EJB with BMT?

Gabriel Aramburu Gabriel Aramburu · Accepted Answer · 2013-07-27T00:47:45

BMT beans cannot participate in an existing transaction

From EJB 3.1 spec.:

13.6.1 Bean-Managed Transaction Demarcation

The container must manage client invocations to an enterprise bean instance with bean-managed transaction demarcation as follows. When a client invokes a business method via one of the enterprise bean’s client views, the container suspends any transaction that may be associated with the client request....

How to propagate a client-side UserTransaction into a stateless session bean using BMT

1 Answers