Writing the Module Components for the sendremote Example

Writing the components of the modules involves two tasks:

• Coding the Application Client: MultiAppServerClient.java

• Coding the Message-Driven Bean: ReplyMsgBean.java

Coding the Application Client: MultiAppServerClient.java

The application client class, multiclient/src/java/MultiAppServerClient.java, does the following.

1. It injects resources for two connection factories and a topic.

2. For each connection factory, it creates a connection, a publisher session, a publisher, a subscriber session, a subscriber, and a temporary topic for replies.

3. Each subscriber sets its message listener, ReplyListener, and starts the connection.

4. Each publisher publishes five messages and creates a list of the messages the listener should expect.

5. When each reply arrives, the message listener displays its contents and removes it from the list of expected messages.

6. When all the messages have arrived, the client exits.

Coding the Message-Driven Bean: ReplyMsgBean.java

The message-driven bean class, replybean/src/ReplyMsgBean.java, does the following:

1. Uses the @MessageDriven annotation:

   @MessageDriven(mappedName="jms/Topic")

2. Injects resources for the MessageDrivenContext and for a connection factory. It does not need a destination resource because it uses the value of the incoming message’s JMSReplyTo header as the destination.

3. Uses a @PostConstruct callback method to create the connection, and a @PreDestroy callback method to close the connection.

The onMessage method of the message-driven bean class does the following:

1. Casts the incoming message to a TextMessage and displays the text

2. Creates a connection, a session, and a publisher for the reply message

3. Publishes the message to the reply topic

4. Closes the connection

On both servers, the bean will consume messages from the topic jms/Topic.