HTTP Web

HTTP错误代码401~502小集锦
http://apps.hi.baidu.com/share/detail/18374373

浅谈HTTP的无状态性
http://www.cnblogs.com/perhaps/archive/2006/06/28/438187.html

Web应用程序状态管理
http://blog.sina.com.cn/s/blog_5ec531c80100e139.html