用户登录中Cookie的简单应用

来源：互联网发布：java web项目面试题编辑：程序博客网时间：2024/05/16 10:06

总共分为三个界面，第一个界面：登录界面

<%@ page language="java" contentType="text/html; charset=utf-8" import="java.net.*"    pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><h1> 用户登录界面</h1><%             request.setCharacterEncoding("utf-8");            String  username="";            String password="";            Cookie[] cookie= request.getCookies();            if(cookie!=null&&cookie.length>0){                                   for(Cookie c:cookie){                                   if(c.getName().equals("username")){                        username=URLDecoder.decode(c.getValue(),"utf-8");                               }            if(c.getName().equals("password")){                        password=URLDecoder.decode(c.getValue(), "utf-8");            }                                    }            }%><form action="dologin.jsp"  method="post">      <table>            <tr>            <td>用户名：</td>            <td><input type="text" name="username" value="<%=username%>"/></td>            </tr>                         <tr>              <td>密码：</td>            <td><input type="password" name="password" value="<%=password%>"/></td>             </tr>                           <tr>               <td colspan="2"> <input type="checkbox" name="isuseCookie" checked="checked"                /> 十天内免密码登录</td>                         </tr>                             <tr>               <td colspan="2" align="center"><input type="submit" value="登录"/></td>               </tr>      </table></form></body></html>

第二个界面：用户请求处理界面

<%@page import="java.net.URLEncoder"%><%@ page language="java" contentType="text/html; charset=utf-8" import="java.net.*"    pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><h1>用户登录成功</h1><br>       <%       request.setCharacterEncoding("utf-8");              String[]  isuseCookie=request.getParameterValues("isuseCookie");             if(isuseCookie!=null&&isuseCookie.length>0){             //保存用户信息到Cookie

                 //特别说明：防止中文乱码，URLEncodeer.encode(String   "字符集");                          String username=URLEncoder.encode(request.getParameter("username"),"utf-8");                          String password=URLEncoder.encode(request.getParameter("password"),"utf-8");                          Cookie usernameCookie= new  Cookie("username",username);             Cookie  passwordCookie= new  Cookie("password",password);             //设置Cookie保存的时间，单位秒             usernameCookie.setMaxAge(864000);             passwordCookie.setMaxAge(864000);             //添加到Cookie             response.addCookie(usernameCookie);                         response.addCookie(passwordCookie);             }             else{             //需要清空Cookie                          Cookie[] cookie =request.getCookies();             if(cookie!=null&&cookie.length>0){                          for(Cookie c:cookie){             if(c.getName().equals("username")||c.getName().equals("password")){             c.setMaxAge(0);//设置Cookie失效             response.addCookie(c);//重新保存Cookie                          }                          }                          }                                                                 }              %>          <br><br><a href="users.jsp">用户信息</a>                          </body></html>

第三个界面：用户界面

<%@page import="java.net.URLDecoder"%><%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><h1>用户信息输出</h1><%           String  username="";            String password="";            Cookie[] cookie= request.getCookies();            if(cookie!=null&&cookie.length>0){                                   for(Cookie c:cookie){                                   if(c.getName().equals("username")){                        username= URLDecoder.decode(c.getValue(),"utf-8");                                 }            if(c.getName().equals("password")){                        password=URLDecoder.decode(c.getValue(), "utf-8");            }                                    }            }%>     用户名为：<%= username %>     密码：<%= password %></body></html>

可以记住用户十天的登录信息，十天内面密码登录

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