摘要
Internet就象是信息的海洋,它包罗万象,为我们的工作和生活带来了极大
的方便。但同时,Internet上的资源又是杂乱无章的,要想快速便捷地找到自己
所需的信息并非一件易事。近年来,教育界不断地向网络方面扩展,如网络教
室、网上图书馆,无一不和网络密切相关。Internet上的教学资源同样存在着零
散无序的特点,只有找到一种有效的解决方案才能使Internet上的教学资源真正
为教育事业所用。本课题提出的方案就是采用基于Cache技术的WWW代理服
务器实现并生成OSE的专用Cache。
基于Cache技术的WWW代理服务器不仅可以实现对OSE资源的收集、
共享,而且具有加速Internet访问、降低网络带宽开销、保密个人信息以及节省
IP地址资源等优点。在论文设计过程中主要通过开发访问控制模块实现对OSE
资源的过滤与存储,并利用各种算法实现对Cache内容的刷新、清除与替换;
同时采用可配置文件增强代理服务器的可控性,使之对于不同的场合与条件具
有较强的适应性。
论文的组织如下:第一章介绍课题的提出并引出课题研究的意义;第二、
三、四章分别介绍代理技术、Cache技术和教学资源共享OSE;第五章介绍系
统的具体设计与实现过程;第六章总结系统存在的不足与设想。
Internet seems like an information ocean which is coverall. It makes our lives
and works much more convenient. At the same time, resources on Internet are
disorderly and unsystematic. It’s always difficult to find what you need quickly and
easily. In recent years, educational field has expanded its developments to networks,
such as teaching on Internet and Web libraries. These are all closely interconnected
with networks. Similarly, educational resources on Internet are out-of-order. So,
we need an effective solution to collect useful educational resources on Internet as
much as possible. In this paper, a Web proxy server based on cache technology is
designed to carry out special proxy and caching for OSE resources.
This Web proxy server who bases on cache technology can not only implement
collection and sharing for OSE resources, but also speed up Internet access rate,
reduce bandwidth consumption, keep personal information secret and save IP address
resources, and so forth. During the design procedure, an access control module is
devised to deputize and filter OSE resources. Furthermore, certain algorithm is used
to refresh, remove and replace objects in cache. A configurable file are also written to
enhance system adaptability. The sizes content-. refresh rate and time-to-live of cache
objects are all configurable. It can be seen that the system possesses strong flexibility
in different cases and conditions.
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