Chapter 6: Web Applications and JMS

Overview

In this chapter we will be looking into developing a web application using the standard J2EE web container services and JMS. The application is a browser-based helpdesk ticket system where customers can log cases, and the system users can view the cases. In the application we will be using JMS as the middleware for integrating two separate web-based systems, one for logging the cases and the other for managing the cases, which function in total isolation to each other. The two systems are not aware of the functional details of each other. The case management system sends JMS messages to a message queue when a user raises a case and the messages in the queue are read by the case management system. Similarly when a case status is updated by the case management system a JMS message is sent to a message queue, which is in turn read by the case logging system.

Note 

This application assumes basic knowledge of J2EE web containers, Java servlets, JavaServer Pages, custom tags, and of course JMS.

We will be covering the following aspects of JMS and J2EE web components in the case study:

• Use of JMS for interfacing two heterogeneous applications functioning in isolation to each other

• Asynchronous message delivery

• Point-to-Point messaging

• Use of JSP custom tags for sending JMS messages

• Use of JSP application scope beans as JMS message listeners

• J2EE web application paradigm

• Use of BEA WebLogic Server 6.0 for deploying JMS-based systems and web applications