The Application Of The J2EE Design Pattern In The Digital Community System

J2EE is a currently popular developing-platform specification which should be obeyed in developing the distributed network application. With the development of the computer network, the enterprise grade applications developed by it have got very extensive application in e-business, e-government affairs, etc..Efficiency is an important issue in application of J2EE. Shortening the response time caused by the network transfers and improving the ability of application to dispose the affairs in unit time should be taken into consideration when designing a system. Another question is how to improve the reuseability and the expansibility of the system modules which are the necessary performances to improve the software quality and extend its life-cycle.J2EE patterns summarized by early developers have been proved useful; therefore they have been adopted in the author's work to solve the reusabilitity and expansibility problems in development of the digital community management system.At first, some essential background knowlege and the overview of the digital community system have been introduced, and an explanation to the reason for choosing J2EE platform has been made. After the functions of the system have been analyzed and its essential summary design been made, the implement of one part of digital community- the EJB layer is taken as an example to make a study. How to choose and use J2EE design patterns are focused on after the system functions being realized. The various influences on the system performance by using these design patterns are dealt with as well. The characteristics 'and the application field of the design patterns with same functions are probed into. And some design patterns that used in the system have been chosen. Various methods to improve the performance of the application system are given from the aspect of using J2EE patterns. And the improvement of the system performance is listed and some views on how to choose the J2EE design patterns are proposed. Finally, The corresponding important codes of some functions and some class picture using these patterns are provided.In conclusion, to develop distributed network application employing J2EE, the design patterns which adapted well to the scale of the application and the environment should be chosen and these patterns can improve some performance of application.