利用Cookie保存用户身份信息实现免登录 

  1 <%@page import="sun.misc.BASE64Encoder"%>
  2 <%@page import="java.util.Base64.Encoder"%>
  3 <%@page import="java.security.MessageDigest"%>
  4 <%@ page language="java" contentType="text/html; charset=UTF-8"
  5     pageEncoding="UTF-8"%>
  6 <%!
  7     //定义MD5加密的KEY
  8     public static final String KEY = "wooyoohoo@163.com";
  9 %>
 10 <%
 11     //设置请求和响应的编码格式
 12     request.setCharacterEncoding("utf-8");
 13     response.setCharacterEncoding("utf-8");
 14     
 15     //判断用户的行为
 16     String action = request.getParameter("action");
 17     
 18     System.out.println(action);
 19     
 20     if("login".equals(action)){
 21         //登录
 22         String userName = request.getParameter("username");
 23         String pwd = request.getParameter("password");
 24         //获取有效时长
 25         String time = request.getParameter("time");
 26         
 27         if(userName!=null && !userName.isEmpty()){
 28             MessageDigest digest = MessageDigest.getInstance("MD5");
 29             //将用户名称+KEY进行MD5加密
 30             String encodeStr = new BASE64Encoder().encode(digest.digest((userName+KEY).getBytes("utf-8")));
 31             //保存用户名称
 32             Cookie userNameCookie = new Cookie("username",userName);
 33             Cookie encodeCookie = new Cookie("ssid",encodeStr);
 34             
 35             //设置有效期
 36             userNameCookie.setMaxAge(Integer.parseInt(time));
 37             encodeCookie.setMaxAge(Integer.parseInt(time));
 38             
 39             //设置Cookie
 40             response.addCookie(userNameCookie);
 41             response.addCookie(encodeCookie);
 42             
 43             //重新访问该页面(添加参数System.currentTimeMillis()禁止浏览器缓存页面内容)------------->此处重新请求该页面是为了在一个页面中处理完毕所有逻辑
 44             response.sendRedirect(request.getRequestURI()+"?"+System.currentTimeMillis());
 45             return;
 46         }
 47     }else if("logout".equals(action)){
 48         //退出[清除userNameCookie和encodeCookie]
 49         Cookie userNameCookie = new Cookie("username","");
 50         Cookie encodeCookie = new Cookie("ssid","");
 51         
 52         userNameCookie.setMaxAge(0);
 53         encodeCookie.setMaxAge(0);
 54         
 55         response.addCookie(userNameCookie);
 56         response.addCookie(encodeCookie);
 57         
 58         //重新访问该页面(添加参数System.currentTimeMillis()禁止浏览器缓存页面内容)------------->此处重新请求该页面是为了在一个页面中处理完毕所有逻辑
 59         response.sendRedirect(request.getRequestURI()+"?"+System.currentTimeMillis());
 60         return;
 61     }
 62     
 63     String account = null;
 64     String ssid = null;
 65     
 66     boolean isLogin = false;
 67     
 68     //获取Cookie信息
 69     Cookie[] cookies = request.getCookies();
 70     if(cookies!=null && cookies.length>0){
 71         //判断用户信息
 72         for(int i=0;i<cookies.length;i++){
 73             if(cookies[i].getName().equals("username")){
 74                 //获取账号
 75                 account = cookies[i].getValue();
 76             }else if(cookies[i].getName().equals("ssid")){
 77                 //获取账号和KEY加密后的字符串
 78                 ssid = cookies[i].getValue();
 79             }
 80         }
 81     }
 82     
 83     if(account!=null && ssid!=null){
 84         System.out.println(account);
 85         String getSSID = new BASE64Encoder().encode(MessageDigest.getInstance("MD5").digest((account+KEY).getBytes("utf-8")));
 86         System.out.println(getSSID);
 87         System.out.println(ssid);
 88         if(getSSID.equals(ssid)){
 89             isLogin = true;
 90         }
 91     }
 92 %>
 93 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 94 <html>
 95 <head>
 96 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 97 <title>利用Cookie实现永久登录</title>
 98 </head>
 99 <body>
100     <% 
101         if(isLogin){
102             %>
103                 <!-- 显示登陆后的信息 -->
104                 <span>欢迎回来<% out.print(account);%></span><button onclick="javascript:{window.location.href='<%=request.getRequestURI()%>?action=logout'}">注销</button>
105             <%
106         }else{
107             %>
108                 <!-- 显示登录界面进行登录操作 -->
109                 <form action="<%=request.getRequestURI()%>?action=login" method="post">
110                     账号:&nbsp;<input type="text" name="username"><br>
111                     密码：<input type="password" name="password">
112                     <br>
113                     <input type="radio" value="<%=30*60 %>" name="time">30分钟有效<br>
114                     <input type="radio" value="<%=7*24*60*60 %>" name="time">7天有效<br>
115                     <input type="radio" value="<%=30*24*60*60 %>" name="time">30天有效<br>
116                     <input type="submit" value="登录">
117                 </form>
118             <%
119         }
120     %>
121 </body>
122 </html>

 

posted @ 2018-08-16 15:01  wooyoohoo  阅读(3431)  评论(0)    收藏  举报