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

An Application ExampleThat Consumes Messages from a Remote Server
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1. The administrator starts two Java EE servers, one on each system.
2. On the local server, the administrator deploys the message-driven bean module, which uses
a connection factory that specifies the remote server where the client is deployed.
3. On the remote server, the administrator places the client JAR file.
4. The client module sends three messages to a queue.
5. The message-driven bean consumes the messages.
Figure 32–3 illustrates the structure of this application. You can see that it is almost identical to
Figure 23–1 except that there are two Java EE servers. The queue used is the one on the remote
server; the queue must also exist on the local server for resource injection to succeed.
FIGURE 32–3 A Java EE Application That Consumes Messages from a Remote Server
Java EE Server on Jupiter
Application
Client
Sends
Msg
Queue
Writing the Module Components for the
consumeremote Example
Writing the components of the modules involves
■ Coding the application client
■ Coding the message-driven bean
Delivers
Msg
Java EE Server on Earth
MDB Instance
EJB
Container
The application client, jupiterclient/src/java/SimpleClient.java, is almost identical to
the one in “The simplemessage Application Client” on page 674.
Similarly, the message-driven bean, earthmdb/src/java/MessageBean.java, is almost
identical to the one in “The Message-Driven Bean Class” on page 675.
The only major difference is that the client and the bean are packaged in two separate modules.
The Java EE 5Tutorial • June 2010