HttpServletRequest类主要处理：
1.读取和写入HTTP头标B:
request.getHeader(String s);
2.取得和设置cookies
request.getCookies();
3.取得路径信息
request.getContextPath();/request.getServletPath();
4.标识HTTP会话
response.setHeader("Refresh","3"); //三秒刷新页面一次
Cookie c1 = new Cookie("username","only"); response.addCookie(c1);
response.setContentType("text/html;charset=utf-8");
HttpServleteResponse.getOutputStream().write();
原文：http://www.cnblogs.com/tjlgdx/p/6262216.html