Application Research Of J2EE Design Patterns

Distributed enterprise application software has the characters of complex structure and involving multi technology. Those characters increase the difficult of its development. So it's necessary to apply design pattern - a reusable programming approach, to design and program software system. This paper discusses the development of OSS (Operation Support System) for telecommunication enterprise using J2EE - the most popular specification of distributed object technology.This paper introduces the technology foundation of developing distributed enterprise application software. Then the character of J2EE design patterns is discussed and summarized based on GoF's design patterns. Two kind of J2EE design patterns are compared and analyzed. For telecommunication OSS, according to the requirement and eTom model, system objects are located, architecture design scheme is provided and modules are divided. Furthermore, structure of web layer is given with the application of front-controller pattern. Using view-helper pattern and intercepting-filter pattern, access control scheme of web layer is designed and realized. Data check of client-side is realized by using view-helper pattern too. Finally, in business layer, several patterns are applied for improving performance. They are session-facade pattern for business object organizing, value-object pattern for data transferring, and service-locator pattern for business object locating.The application of J2EE design patterns establishes the foundation for developing OSS with clear structure and high performance.