A Durable Subscription Example

The DurableSubscriberExample.java program shows how durable subscriptions work. It demonstrates that a durable subscription is active even when the subscriber is not active. The program contains a DurableSubscriber class, a MultiplePublisher class, a main method, and a method that instantiates the classes and calls their methods in sequence.

The program is in the following directory:

tut-install/javaeetutorial5/examples/jms/advanced/durablesubscriberexample/src/java/

The program begins in the same way as any publish/subscribe program: The subscriber starts, the publisher publishes some messages, and the subscriber receives them. At this point, the subscriber closes itself. The publisher then publishes some messages while the subscriber is not active. The subscriber then restarts and receives the messages.

Before you run this program, compile and package the source file and create a connection factory that has a client ID. Perform the following steps:

1. To compile and package the program using NetBeans IDE, follow these steps:

   1. In NetBeans IDE, choose Open Project from the File menu.

   2. In the Open Project dialog, navigate to tut-install/javaeetutorial5/examples/jms/advanced/.

   3. Select the durablesubscriberexample folder.

   4. Select the Open as Main Project check box.

   5. Click Open Project.

   6. Right-click the project and choose Build.

   To compile and package the program using Ant, follow these steps:

   1. Go to the following directory:

      tut-install/javaeetutorial5/examples/jms/advanced/durablesubscriberexample/
      

   2. Type the following command:

      ant

2. If you did not do so for A Message Acknowledgment Example, create a connection factory named jms/DurableConnectionFactory:

   ant create-durable-cf

To run the program using NetBeans IDE, right-click the durablesubscriberexample project and choose Run.

To run the program from the command line, follow these steps:

1. Go to the dist directory:

   cd dist

2. Type the following command:

   appclient -client durablesubscriberexample.jar

The output looks something like this:

Connection factory without client ID is jms/ConnectionFactory
Connection factory with client ID is jms/DurableConnectionFactory
Topic name is jms/Topic
Starting subscriber
PUBLISHER: Publishing message: Here is a message 1
SUBSCRIBER: Reading message: Here is a message 1
PUBLISHER: Publishing message: Here is a message 2
SUBSCRIBER: Reading message: Here is a message 2
PUBLISHER: Publishing message: Here is a message 3
SUBSCRIBER: Reading message: Here is a message 3
Closing subscriber
PUBLISHER: Publishing message: Here is a message 4
PUBLISHER: Publishing message: Here is a message 5
PUBLISHER: Publishing message: Here is a message 6
Starting subscriber
SUBSCRIBER: Reading message: Here is a message 4
SUBSCRIBER: Reading message: Here is a message 5
SUBSCRIBER: Reading message: Here is a message 6
Closing subscriber
Unsubscribing from durable subscription

After you run the program, you can delete the connection factory jms/DurableConnectionFactory. Go to the directory tut-install/javaeetutorial5/examples/jms/advanced/durablesubscriberexample/ and type the following command:

ant delete-durable-cf

To delete the class and JAR files for the program using NetBeans IDE, right-click the project and choose Clean.

To delete the class and JAR files for the program using Ant, type the following:

ant clean