Writing the components of the modules involves
Coding the application client
Coding the message-driven bean
The application client, jupiterclient/src/java/SimpleClient.java, is almost identical to the one in The simplemessage Application Client.
Similarly, the message-driven bean, earthmdb/src/java/MessageBean.java, is almost identical to the one in The Message-Driven Bean Class.
The only major difference is that the client and the bean are packaged in two separate modules.