web server - Borland Technical Publications

JMS and Transactions
For instance:
import javax.jms.*;
QueueConnectionFactory nonXAQCF;
Queue
myQueue;
try {
javax.naming.Context ctx = (javax.naming.Context) new
javax.naming.InitialContext();
nonXAQCF = (QueueConnectionFactory) ctx.lookup("java:comp/env/jms/
MyJMSQueueConnectionFactory");
myQueue = (Queue) ctx.lookup("java:comp/env/jms/MyJMSQueue");
}
catch (javax.naming.NamingException exp) {
exp.printStackTrace();
}
// Note: A global transaction context is currently active when the Session is
being created
QueueSession qSession = conn.createQueueSession(false,
Session.AUTO_ACKNOWLEDGE);
QueueSender = qSession.createSender(myQueue);
TextMessage msg = qSession.createTextMessage("A Message ");
sender.send(msg);
Here, the TextMessage msg is queued regardless of the outcome of the active global
transaction. This is in line with test cases in the J2EE Compatibility Test Suite (CTS
1.3.1). It seems useful to have this capability in a global transaction, whereby a log
message needs to be sent irrespective of the enclosing global transaction's completion
result.
Multiple resource access within a single global transaction is supported in BES. This
provides the capability to do a unit of work which is composed of sending/receiving
JMS messages along with some other type of resource manager access. That is, it is
desirable to write code (in an EJB for example) which does some work against a non
JMS resource such as a database and also send a message to a queue with the
Container providing transactional completion for all work performed. Upon completion
of the transaction, either the work performed against the database is committed AND
the message is queued, or should something fail during the transaction database work
is rolled back AND the message is not delivered to the queue.
In application code, an EJB method such as doSomeWork() shown below is supported in
BES:
// Business method in a session bean, the EJB container marks the transaction
void doSomeWork()
{
// Establish a database connection
java.sql.Connection dbConn = datasource.getConnection();
// Execute SQL
...
}
// Call a remote EJB in the same transaction
ejbRemote.doWork();
// Send a JMS message to a queue
jmsSender.send(msg);
218 BES Developer’s Guide