"domain was null"; rmicontext=false; JTA UserTransaction;EJB Transaction

Question

Hi folks!
I´m doing a test with EJB´s and JTA transactions.
The goal of the test is to verify if the OC4J will recognize a JTA User Transaction opened by a client just before an EJB method invocation and use it inside the EJB method, instead of opening a new transaction.
So, I have an EJB with conteiner managed transaction feature "Required".
And I have a client of this EJB, that opens a JTA UserTransaction and performs some updates and calls the EJB.
After the EJB call, I throwed a RuntimeException. The proposal of throwing this exception is to force the rollback of all the transaction ( the updates made by the client and the updates made by the ejb must not be commited ).
My method seems like this ( actually it´s a little bit more structured, but for understading purporses, i put it all in one method only here ):
<pre>
public void testTransaction () {
boolean commit = false;
javax.transaction.UserTransaction ut = null;
try {
// getting the JTA Transaction
javax.naming.Context initCtx = new javax.naming.InitialContext();
ut = (javax.transaction.UserTransaction) initCtx.lookup("java:comp/UserTransaction");
ut.begin();
try{
//issue the update
Connection conn = null;
try {
Context ic = new InitialContext();
     DataSource ds = (DataSource) ic.lookup("jdbc/JTADS");
     conn = ds.getConnection();
     PreparedStatement stmt = conn.prepareStatement("UPDATE dont_drop_this_table set field2 =? where field1 = ?");
     stmt.setString(1, "First Record");
     stmt.setInt(2, 1);
     stmt.executeUpdate();
} finally {
if (conn != null) conn.close();
//issue another update via EJB
Hashtable env = new Hashtable();
String initialContextFactory = "com.evermind.server.rmi.RMIInitialContextFactory";
String securityPrincipal = "jazn.com/admin";//admin
String securityCredentials = "welcome";//admin
String providerUrl = "ormi://localhost:23791/jta";
env.put(Context.INITIAL_CONTEXT_FACTORY, initialContextFactory);
env.put(Context.SECURITY_PRINCIPAL, securityPrincipal);
env.put(Context.SECURITY_CREDENTIALS, securityCredentials);
env.put("dedicated.rmicontext", "false");
env.put("dedicated.connection", "false");
env.put(Context.PROVIDER_URL, providerUrl);
Context ctx = new InitialContext(env);
Object home = ctx.lookup(jndiName);
Object o = PortableRemoteObject.narrow(home, Class.forName("mytest.MyEJBHome"))
Class clazz = o.getClass();
Method method = clazz.getMethod("create", null);
MyEJBBean bean = (MyEJBBean) method.invoke(o, null);
//invoking ejb
bean.updateTable(2, "Second Record")
//force an ArrayOutOfBoundsException, in order to test
//if the EJB container will rollback or commit the ejb transaction.
int x[] = { 0 };
x[1] = 1;
x[2] = 1;
} catch (Exception e) {
throw new RuntimeException(e);
//if there was no exception thrown until here... then commit
commit = true;
catch ( Exception e ) {
throw new RuntimeException (e);
finally {
try {
if ( commit ) ut.commit();
else ut.rollback();
} catch ( Exception e ) {
throw new RuntimeException (e);
</pre>
Now my question:
When I use dedicated.rmicontext = true or dedicated.connection = true, the EJB container commits the transaction, even after the exception thrown. I understand that EJB container open a new transaction, instead of use the existing one ( jta UserTransaction.
When I use dedicated.rmicontext = false and dedicated.connection = false, the EJB container rollbacks the transaction, as I expected.
I´ve seen many posts about "domain was null" message after a NullPointerException.
I did many tests, but no NullPointerException was thrown, even when calling the EJB remotely nor issuing concurrent calls.
- I need the container rollback the transaction.
- I found that it only rollbacks when I put dedicated.rmicontext = false and dedicated.connection = false.
- I found that when dedicated.rmicontext = false and dedicated.connection = false, a NullPointerException may ocurr.
This "domain was null" problem seems to be an OC4J bug and the rmicontext=true an workaround for this bug, but I can´t use rmicontext=true because it will make the EJB transaction not to be the same JTA UserTransaction opened before the EJB call.
Is there any other way to make an EJB transaction be the same JTA UserTransaction openned before the EJB call?
PS: I´m using JDeveloper 10.1.2
Thanks for any help...

Answer 1

Can anybody help me?
I need to know how can I set my EJB to use the same connection opened by a POJO class via JTA. ( Actually I need the EJB and POJO class be in same JTA transaction )
If I set the dedicated.rmicontext to false, it works but I run to risk of getting a NullPointerException "domain was null".
I realy need your help!
Thanks!