The Research And Application Of Design Patterns Used In Information System Based On J2EE Platform

The main content of the thesis is to explore the software design pattern of SIMS(Student Information Management System),which has a high stabilization, safety and credibility, good migration and cross-platform, by taking example of SIMS in "digital campus" construction.SIMS is a very important module of "digital campus" information system which is based on URP system architecture and realization scheme. The thesis starts with the business model of the SIMS, presents the requirement of the information system via the UML UserCase diagram. According to the analysis of the UserCase, it is easy to find out the objects which need persistence and their relationship, and to use entity-relation model and the third normal formula (3NF) to produce the database and its table forms. On this foundation, we analyze and design the architecture of SIMS. Using J2EE application system architecture based on MVC pattern in the process of design to divide the system into 12 function modules, by means of this architecture to make these modules independent with each other and benefit the parallel development in a team. In the realization of each module use multiple key techniques in the J2EE and classic Java design pattern to decrease the coupling between each module. In the design of the login module, we firstly describe how to use entity bean to realize data persistence, and then use the Session Facade to realize the encapsulation of the module. In the design of the student status management module use DAO design pattern to abstract and encapsulate the access of all kinds of data source and to depart the business logic and data base access logic and use Value Object design pattern to integrate the attribute variables of EJB to one date object, by this means it is easy to enhance the remote transmission efficiency via coarse grained data object.In the design of the controller module use ActionServlet in the Structs Framework to realize the logical transaction between page transformation and modules. In the design of presentation layer, we choose the technique of JSP. In order to integrate local system with other application system, we give an example in the thesis to show how to release the component as Web service. Finally, we pack all these components and deploy it in the Oracle 10g Application Server.This thesis put emphasis on the architecture design and realization of the SIMS, and for the purpose of extracting a general software framework for campus informationconstruction. In the whole process of design and realization of this system, we use UML diagram as description document, and combined with uniform process to realize the iteration of the items and incremental development.