problem with usertransaction annotation

[bridge007]

Hi,

I'm trying to migrate a session bean from ejb 2.1 to ejb 3.0.
The migration is almost finished, but I have a problem while migrating
the usertransaction. I want to use an annotation.
The annotation works fine for the datasource, but for the usertransaction it has no effect. I always get a NullpointerException.

This is the code before the usertransaction migration, but with datasource migration to ejb 3.0:

@Resource protected SessionContext c_sctSContext = null;
@Resource(mappedName="java:/LABSP_DS") javax.sql.DataSource database;
 protected javax.transaction.UserTransaction ut;
 ...
protected Connection initTransactionWithConnection()
 throws BSConnectionTroubleException {
 Connection returnConnection = null;

 try {
 this.ut = this.c_sctSContext.getUserTransaction();

 if (this.ut.getStatus() != javax.transaction.Status.STATUS_NO_TRANSACTION) {
 getLogger()
 .debug(
 this
 + "Failure Transaction State != Status.STATUS_NO_TRANSACTION (" + this.ut.getStatus() + ")"); //$NON-NLS-1$ //$NON-NLS-2$

 throw new BSConnectionTroubleException(
 "Failure Transaction State != Status.STATUS_NO_TRANSACTION (" + this.ut.getStatus() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
 }

 returnConnection = getConnection();
 this.ut.begin();

 } catch (Exception e) {
 getLogger().error("Error init connection/transaction:", e); //$NON-NLS-1$

 throw new BSConnectionTroubleException("Could not connect to database", e); //$NON-NLS-1$
 }

 return returnConnection;
 }

This code works fine.

Now my migration of the usertransaction (add of resource annotation and elemination of usertransaction lookup):

@Resource protected SessionContext c_sctSContext = null;
@Resource(mappedName="java:/LABSP_DS") javax.sql.DataSource database;
@Resource protected javax.transaction.UserTransaction ut;
 ...
protected Connection initTransactionWithConnection()
 throws BSConnectionTroubleException {
 Connection returnConnection = null;

 try {

 if (this.ut.getStatus() != javax.transaction.Status.STATUS_NO_TRANSACTION) {
 getLogger()
 .debug(
 this
 + "Failure Transaction State != Status.STATUS_NO_TRANSACTION (" + this.ut.getStatus() + ")"); //$NON-NLS-1$ //$NON-NLS-2$

 throw new BSConnectionTroubleException(
 "Failure Transaction State != Status.STATUS_NO_TRANSACTION (" + this.ut.getStatus() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
 }

 returnConnection = getConnection();
 this.ut.begin();

 } catch (Exception e) {
 getLogger().error("Error init connection/transaction:", e); //$NON-NLS-1$

 throw new BSConnectionTroubleException("Could not connect to database", e); //$NON-NLS-1$
 }

 return returnConnection;
 }

After this migration, I always get a NullpointerException on line:

if (this.ut.getStatus() != javax.transaction.Status.STATUS_NO_TRANSACTION)

This is because the usertransaction was not injected. The question is why?
Help is welcome!
Any idea?