The Java EE 5 Tutorial (PDF) - Oracle Software Downloads

Writing Simple JMS Client Applications
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}
}
Because the control message is not a TextMessage, the receiving program terminates the
while loop and stops receiving messages after the control message arrives.
7. Closes the connection in a finally block, automatically closing the session and
MessageConsumer.
The receive method can be used in several ways to perform a synchronous receive. If you
specify no arguments or an argument of 0, the method blocks indefinitely until a message
arrives:
Message m = consumer.receive();
Message m = consumer.receive(0);
For a simple client program, this may not matter. But if you do not want your program to
consume system resources unnecessarily, use a timed synchronous receive. Do one of the
following:
■ Call the receive method with a timeout argument greater than 0:
Message m = consumer.receive(1); // 1 millisecond
■ Call the receiveNoWait method, which receives a message only if one is available:
Message m = consumer.receiveNoWait();
The SynchConsumer program uses an indefinite while loop to receive messages, calling receive
with a timeout argument. Calling receiveNoWait would have the same effect.
Starting the JMS Provider
When you use the Application Server, your JMS provider is the Application Server. Start the
server as described in “Starting and Stopping the Application Server” on page 68.
Creating JMS Administered Objects for the Synchronous Receive
Example
Creating the JMS administered objects for this section involves the following:
■ Creating a connection factory
■ Creating two destination resources
If you built and ran the SimpleMessage example in Chapter 23, “A Message-Driven Bean
Example,” and did not delete the resources afterward, you need to create only the topic resource.
You can create these objects using the Ant tool. To create all the resources, do the following:
1. In a terminal window, go to the producer directory:
The Java EE 5Tutorial • June 2010