Separation of Navigation Routing Code in J2EE Web Applications

The navigation routing code of a web application is the part of the code involved in routing a request from a web page through the appropriate components on the server, typically ending with the display of a response page. Common maintenance activities are to change the sequence of pages or the processing for a page, and for these activities the navigation routing code must be located, understood, and possibly modified. But in J2EE applications this code is spread among a number of components, making maintenance costly. We describe an approach for separating this navigation routing code, using either Aspect Oriented Programming (AOP) or conventional OO techniques. We demonstrate how this improves maintainability by converting three exemplar applications from Sun and Oracle, with a 4- to 11-fold reduction in the number of files containing navigation routing code and in the lines of code in these files.