The application of architectural and design patterns in enterprise systems

Abstract

This thesis investigates the use of various J2EE technologies and the application o f best practice in the use of these technologies. It uses the knowledge gained in this investigation to develop a demonstration application designed for use in the teaching o f these technologies. The demonstration application is designed to lead students from the development o f standalone components to the development and integration of composite components in a complete working application. The learning experience is enhanced as students must identify design faults at various stages of development, and attempt solutions, before being introduced to design patterns that resolve the faults. In this way students get a real appreciation o f the benefits o f the patterns. Various exercises are identified throughout the thesis to re-inforce the learning. Java 2 Enterprise Edition (J2EE) is a specification from Sun Microsystems for developing multi-tiered distributed applications. J2EE covers a wide range of technologies that are applied across various tiers in an n-tiered architecture. Learning to use these various technologies is not a trivial task and there is a strong demand for experienced J2EE developers. “J2EE requires significant knowledge and is not for the faint-hearted. Enterprise platforms are inherently complex, slowing down advanced Java developers and creating a barrier to entry for many mainstream developers. There is a critical shortage of advanced Java developers, and especially Java developers with expertise in Enterprise Java Beans (ETBs)". [1] John Crupi, Distinguished Engineer, Chief Java Architect, Sun Microsystems, Frank Baerveldt, Director o f Software Architecture, Compuware Corporation. “Implementing Sun Microsystems’ Core J2EE Patterns”, 2005 However, learning to use the various J2EE technologies is no guarantee that these technologies will be used to apply good design practice. By applying architectural and design patterns, developers learn from the experiences of experts. “Learning to design comes from experience and from sharing knowledge on best practices and bad practices". [2] Deepak Alur, John Crupi and Dan Malks. Core J2EE Patterns (Best Practices and Design Strategies) 2nd Edition (Prentice Hall, 2003).