Based On J2ee Four-story Structure And Component Technology, Distance Education Support Platform

The platform of distance education is the base of distance education. Its performance and functions directly decide the teaching quality, studying effect and management level. The thesis introduces the architecture of the Web application system based on J2EE four-tier structure and component technology, and discusses in detail the system analysis, design and key-technology.The system uses UML method to analyze, and then create the function model and object model. The system is divided into three sub-systems according to its function. They are on-line education, administration and educational resources.The system employs J2EE four-tier based structure. Browser provides visual graphic interface; Web Server responds to the requests of the clients; Application Server processes application, computation and data operation; DB Server stores and administrates information. The implementation of multi-tier structure enables the system to have distinguished quality of flexibility, currency and compatibility.This system involves all types of data information. So it employs DBMS and file system combined to store, organize, and administrate information. The thesis thoroughly discusses the design and optimization of DBMS and file system, integrality and consistence of the data and data redundancy. With the introduction of the information life conception, the system manages to acquire the quality self-restoration and data update system, which maintains the stability of the system.The system adopts JSP and Servlet combined structure to realize the data access based on Web. And with the application of component technology, the efficiency and quality of the development is greatly improved and the work of maintenance is reduced. The system applied Java encrypt technology to accomplish client information encrypt and registration, and applied connection pool technology to enhance the DB operation efficiency.