Design Pattern Based J2ee System

With the development of object-oriented technology, how to design reusable object-oriented software becomes more and more popular. As the complexity of software systems increases, design problems can't be resolved by individual experience, it is important to use experience of experienced software designers. After domain of architecture brought forward that designing experience should be recorded as design patterns, software engineering admitted the idea ,then design pattern of software came forth. Design pattern describes a particular recurring design problem that arises in specific design contexts, and presents a well-proven generic scheme for its solution. The solution scheme is specified by describing its constituent components, their responsibilities and relationships, and the ways in which they collaborate.To study about a design pattern, mastering not only its structure but also its design idea is important, it's base to apply the design pattern agilely. Design pattern is not insulating, there are lots of relation between them, it is key to design good software system that how to mastering the relation and combining design patterns.This paper researchs how to apply design pattern in J2EE-based software system properly. This paper introduces design patern firstly. Then analyze some J2EE core patterns such as MVC, Skin, Front Controller, Business Delegate, Data Access Object, Data Transfer Object and Factory Method. And then discusses the process that applying design pattern to a project in detail. At last, gives a conclusion to this paper and personal thought and propose about design pattern.