Multi-level Filters Technology Research on Application of Network Examination System

摘要

Network examination system is among the hot issues of current education research. In this essay, the author briefly explains the basic principle of filter technology, and then introduces three applications of filter technology. Candidate examination host IP address filtering which is used to prevent candidate cheating;user access permission control filtering which is used to make sure right user has right access permission;Chinese character garbling filtering which is used to prevent garbling in Java developed system. There is no need to code every Servlet or JSP page with filter support in the network examination system, thus filter can greatly improve developing efficiency'. Also filter would make a decision before user's incoming request which can mainly release server's burden.