Accommodating Changing Requirements with EJB

Component Based Software Development promises to lighten the task of web application developers by providing a standard component architecture for building distributed object oriented business applications. Hard evidence consolidat-ing this promise has yet to be provided, especially knowing that the standard libraries of today’s programming languages offer considerable support for distribution (e.g. remote method invocations, database interfaces). Therefore, this paper compares three Java implementations of the same functionality – one using straightforward library-calls, one using a custom-made framework and one using the Enterprise Java Beans framework (EJB) – to assess the maintainability of each of the approaches. We ob-serve that EJB results in better maintainability (code is less complex and exhibits more explicit weak coupling) but that the framework version without the framework cost results in comparable numbers. Therefore, we conclude that Component Based Software Development is necessary for building websystems that will continue to survive in the context of rapidly changing requirements.