try (JMSContext context = durableConnectionFactory.createContext();) {
    context.stop();
    consumer = context.createDurableConsumer(topic, "MakeItLast");
    listener = new TextListener();
    consumer.setMessageListener(listener);
    context.start();
    ...

try (JMSContext context = durableConnectionFactory.createContext();) {
    System.out.println("Unsubscribing from durable subscription");
    context.unsubscribe("MakeItLast");
} ...

To Create Resources for the Durable Subscription Example

To Run the Durable Subscription Example

To Run the unsubscriber Example

After you have finished running the DurableConsumer client, run the unsubscriber example to unsubscribe from the durable subscription.

1. A retailer (retailer/src/main/java/javaeetutorial/retailer/Retailer.java) sends a MapMessage to a vendor order queue, ordering a quantity of computers, and waits for the vendor’s reply:

   outMessage = context.createMapMessage();
   outMessage.setString("Item", "Computer(s)");
   outMessage.setInt("Quantity", quantity);
   outMessage.setJMSReplyTo(retailerConfirmQueue);
   context.createProducer().send(vendorOrderQueue, outMessage);
   System.out.println("Retailer: ordered " + quantity + " computer(s)");
   orderConfirmReceiver = context.createConsumer(retailerConfirmQueue);

2. The vendor (vendor/src/main/java/javaeetutorial/retailer/Vendor.java) receives the retailer’s order message and sends an order message to the supplier order topic in one transaction. This JMS transaction uses a single session, so you can combine a receive from a queue with a send to a topic. Here is the code that uses the same session to create a consumer for a queue:

   vendorOrderReceiver = session.createConsumer(vendorOrderQueue);

   The following code receives the incoming message, sends an outgoing message, and commits the JMSContext. The message processing has been removed to keep the sequence simple:

   inMessage = vendorOrderReceiver.receive();
   // Process the incoming message and format the outgoing
   // message
   ...
   context.createProducer().send(supplierOrderTopic, orderMessage);
   ...
   context.commit();

   For simplicity, there are only two suppliers, one for CPUs and one for hard drives.

3. Each supplier (genericsupplier/src/main/java/javaeetutorial/retailer/GenericSupplier.java) receives the order from the order topic, checks its inventory, and then sends the items ordered to the queue named in the order message’s JMSReplyTo field. If it does not have enough of the item in stock, the supplier sends what it has. The synchronous receive from the topic and the send to the queue take place in one JMS transaction:

   receiver = context.createConsumer(SupplierOrderTopic);
   ...
   inMessage = receiver.receive();
   if (inMessage instanceof MapMessage) {
       orderMessage = (MapMessage) inMessage;
   } ...
   // Process message
   outMessage = context.createMapMessage();
   // Add content to message
   context.createProducer().send(
            (Queue) orderMessage.getJMSReplyTo(),
            outMessage);
   // Display message contents
   context.commit();

4. The vendor receives the suppliers' replies from its confirmation queue and updates the state of the order. Messages are processed by an asynchronous message listener, VendorMessageListener; this step shows the use of JMS transactions with a message listener:

   MapMessage component = (MapMessage) message;
   ...
   int orderNumber = component.getInt("VendorOrderNumber");
   Order order = Order.getOrder(orderNumber).processSubOrder(component);
   context.commit();

5. When all outstanding replies are processed for a given order, the vendor message listener sends a message notifying the retailer whether it can fulfill the order:

   Queue replyQueue = (Queue) order.order.getJMSReplyTo();
   MapMessage retailerConfirmMessage = context.createMapMessage();
   // Format the message
   context.createProducer().send(replyQueue, retailerConfirmMessage);
   context.commit();

6. The retailer receives the message from the vendor:

   inMessage = (MapMessage) orderConfirmReceiver.receive();

   The retailer then places a second order for twice as many computers as in the first order, so these steps are executed twice.

Figure 49-1 Transactions: JMS Client Example

To Create Resources for the transactedexample Example

To Run the transactedexample Clients

You will need four terminal windows to run the clients. Make sure that you start the clients in the correct order.