Advanced Queuing - Oracle

General Features of JMS
A JMS Connection to the database can be created by invoking
createQueueConnection() or createTopicConnection() and passing
the parameters username and password on the QueueConnectionFactory and
TopicConnectionFactory object respectively.
Connection Setup
A JMS client typically creates a Connection, Session and a number of
MessageProducers and MessageConsumers. In the current version only one
open session for each connection is allowed, except in the following cases:
If the JDBC oci8 driver is used to create the JMS Connection
If the user provides an OracleOCIConnectionPool instance during JMS
Connection creation
When a Connection is created it is in stopped mode. In this state no messages can be
delivered to it. It is typical to leave the Connection in stopped mode until setup is
complete. At that point the Connection’s start() method is called and messages
begin arriving at the Connection’s consumers. This setup convention minimizes any
client confusion that may result from asynchronous message delivery while the
client is still in the process of setup.
It is possible to start a Connection and to perform setup subsequently. Clients that
do this must be prepared to handle asynchronous message delivery while they are
still in the process of setting up. A MessageProducer can send messages while a
Connection is stopped.
Some of the methods that are supported on the Connection object are
start() - start, or restart, a Connection’s delivery of incoming messages.
stop() - Used to temporarily stop a Connection’s delivery of incoming
messages. When stopped, delivery to all the Connection’s message consumers
is inhibited. Also, synchronous receive’s block and messages are not delivered
to message listener
close() - close the JMS session and release all associated resources
createQueueSession(true, 0) - create a queue session
createTopicSession (true, 0) - create a topic session
setExceptionListener (ExceptionListener) - set an exception
listener for the connection. This allows a client to be asynchronously notified of
a problem. Some connections only consume messages so they have no other
way to learn the connection has failed.
Creating Applications Using JMS 12-9