I've followed the documentation to attach a foreign TM (JOTM) to JBoss but with not that much luck: Here are the steps

1. Created MBean -->

JOTMTransactionManagerService extends ServiceMBeanSupport implements ObjectFactory,
 JOTMTransactionManagerServiceMBean

2. In the startService, :
i. Created respective objects

ts = new Jotm(true, true);// TMService
 tm = ts.getTransactionManager(); //TransactionManager
 ut = ts.getUserTransaction(); // user tx

ii. Bound the TPCImpl and TPCFactory along wiht TM

bindRef(JNDI_NAME,"org.objectweb.transaction.jta.TransactionManager");
bindRef(JNDI_IMPORTER,"com.mizuho.london.cmi2.framework.transaction.TPCImporter");
bindRef(JNDI_EXPORTER,"com.mizuho.london.cmi2.framework.transaction.TPCFactory");

(Note: TPCImporter and TPCFactory implement Jboss's interfaces with null return implementations. No specific code in there yet.)
3. in the conf/jboss-service.xml file, I commented the in memory TM and added the following code for my JOTM Tx Manager.

<mbean code="framework.transaction.JOTMTransactionManagerService"
 name="jboss:service=TransactionManager"
 xmbean-dd="resource:xmdesc/JOTMTransactionManagerService-xmbean.xml">
 <attribute name="TransactionTimeout">300</attribute>
 <attribute name="GlobalIdsEnabled">true</attribute>
 <depends optional-attribute-name="XidFactory">jboss:service=XidFactory</depends>
 </mbean>

When the server started, it's complaining about JDBCStateManager:

2005-04-06 13:47:41,492 TRACE [framework.transaction.JOTMTransactionManagerService] Constructing
2005-04-06 13:47:41,570 DEBUG [org.jboss.util.NestedThrowable] org.jboss.util.NestedThrowable.parentTraceEnabled=true
2005-04-06 13:47:41,570 DEBUG [org.jboss.util.NestedThrowable] org.jboss.util.NestedThrowable.nestedTraceEnabled=false
2005-04-06 13:47:41,570 DEBUG [org.jboss.util.NestedThrowable] org.jboss.util.NestedThrowable.detectDuplicateNesting=true
2005-04-06 13:47:41,570 ERROR [org.jboss.mq.sm.jdbc.JDBCStateManager] Starting failed jboss.mq:service=StateManager
org.jboss.mq.SpyJMSException: Error creating connection to the database.; - nested throwable: (java.lang.NullPointerException)
 at org.jboss.mq.sm.jdbc.JDBCStateManager$JDBCSession.<init>(JDBCStateManager.java:542)
 at org.jboss.mq.sm.jdbc.JDBCStateManager.initDB(JDBCStateManager.java:432)
 at org.jboss.mq.sm.jdbc.JDBCStateManager.startService(JDBCStateManager.java:399)
 at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:272)
 at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java

etc etc..

It looks like the in the JDBCStateManager code where it calls the begin method on tm (tm.begin()), the tm is null. I'm not quite sure though.

If I'm doing wrongly, can anyone advise me? If not, can anyone tell me what's going on?

(note that the I've serialised JOTM's TransactionFactoryImpl and bound it to JNDI)

I could see the TransactionManager and TPC stull bound royally to the JNDI though!

Thanks
/M