httpheader上的user属性 加个iv代表跨服务器中获取user值
和request.getHeader()相关的知识
如果在地址栏中输入地址：http://localhost:7080/nadlibrary/book/user/booklist
在request里面可以取到如下信息
System.out.println("rotocol: " + request.getProtocol()); ////获取客户端向服务器端传送数据的协议名称
rotocol: HTTP/1.1
System.out.println("Scheme: " + request.getScheme()); //返回的协议名称.默认是http
Scheme: http
System.out.println("Server Name: " + request.getServerName() );//可以返回当前页面所在的服务器的名字;如果你的应用部署在本机那么其就返回localhost或者127.0.0.1
Server Name: localhost
System.out.println("Server Port: " + request.getServerPort()); //可以返回当前页面所在的服务器使用的端口
Server Port: 7080
System.out.println("Remote Addr: " + request.getRemoteAddr()); //获得客户端的ip地址
Remote Addr: 127.0.0.1
System.out.println("Remote Host: " + request.getRemoteHost());//获得客户端的主机名
Remote Host: 127.0.0.1
System.out.println("Character Encoding: " + request.getCharacterEncoding()); //返回字符编码
Character Encoding: utf8
System.out.println("Content Length: " + request.getContentLength()); //
Content Length: -1
System.out.println("Content Type: "+ request.getContentType()); //定义网络文件的类型和网页的编码，决定浏览器将以什么形式、什么编码读取这个文件
Content Type: null
System.out.println("Auth Type: " + request.getAuthType()); //如果servlet由一个鉴定方案所保护，如HTTP基本鉴定，则返回方案名称
Auth Type: null
System.out.println("HTTP Method: " + request.getMethod());//返回HTTP请求方法（例如GET、POST等等）
HTTP Method: GET
System.out.println("path Info: " + request.getPathInfo()); //返回在URL中指定的任意附加路径信息
path Info: null
System.out.println("path Trans: " + request.getPathTranslated()); //返回在URL中指定的任意附加路径信息，被子转换成一个实际路径
path Trans: null
System.out.println("Query String: " + request.getQueryString());//返回查询字符串，即URL中?后面的部份。
Query String: null
System.out.println("Remote User: " + request.getRemoteUser()); //如果用户通过鉴定，返回远程用户名，否则为null
Remote User: null
System.out.println("Session Id: " + request.getRequestedSessionId());//返回客户端的会话ID
Session Id: E2D9AD01880BDC232A134FFCCE280941
System.out.println("Request URI: " + request.getRequestURI()); //返回URL中一部分，从“/”开始，包括上下文，但不包括任意查询字符串
Request URI: /nadlibrary/book/user/booklist
System.out.println("Servlet Path: " + request.getServletPath());//返回请求URI上下文后的子串
Servlet Path: /book/user/booklist
request.getHeader头,它能获取到用户访问链接的信息
System.out.println("Accept: " + request.getHeader("Accept"));
System.out.println("Host: " + request.getHeader("Host"));
System.out.println("Referer : " + request.getHeader("Referer"))//是指你访问这个链接前的上一个链接 ;
System.out.println("Accept-Language : " + request.getHeader("Accept-Language"));
System.out.println("Accept-Encoding : " + request.getHeader("Accept-Encoding"));
System.out.println("User-Agent : " + request.getHeader("User-Agent"));
System.out.println("Connection : " + request.getHeader("Connection"));
System.out.println("Cookie : " + request.getHeader("Cookie"));
System.out.println("Created : " + session.getCreationTime());
System.out.println("LastAccessed : " + session.getLastAccessedTime());
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Host: localhost:7080
Referer : null
Accept-Language : zh-CN,zh;q=0.8
Accept-Encoding : gzip,deflate,sdch
User-Agent : Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
Connection : keep-alive
Cookie : JSESSIONID=E2D9AD01880BDC232A134FFCCE280941
Created : 1358671508064
LastAccessed : 1358671508517
