The idea behind the messaging example is that our application will send an order form to the backend system using JMS. The backend system here is a Python script that accesses the JMS messaging server, ActiveMQ.
In this messaging example, we use an open-source JMS messaging server, ActiveMQ, that is a part of the Geronimo application server. ActiveMQ is very good for testing our application since it supports a protocol called STOMP (Streaming Text Oriented Messaging Protocol, a text based protocol). STOMP enables many kinds of programming languages to participate in JMS messaging (even Telnet is possible; useful for quick testing) so we can use the existing tool as our "order system" in our example. When the "order system" (a Python program) receives the order it verifies it. Then, we manually send an order confirmation message back to the ActiveMQ messaging system and to our application. Then our application updates the web...