JSP Cookie状态管理

转载

mb5fe55992193c7 2019-01-06 11:10:00

文章标签 html css java javascript jquery 文章分类 MySQL 数据库

JSP中创建与使用Cookie

　　创建Cookie对象

　　　　Cookie newCookie = new Cookie(String key, Object value);

　　写入Cookie对象

　　　　response.addCookie(newCookie);

　　读取Cookie对象

　　　　Cookie[] cookies = request.getCookies();

　　常用方法

　　　　void setMaxAge(int expiry)　　设置cookie有效期，单位-秒

　　　　void setValues(String value) 对cookie进行赋值

　　　　String getName()　　　　　　获取cookie的名称

　　　　String getValue()　　　　　　获取cookie的值

　　　　int getMaxAge()　　　　　　获取cookie有效时间，单位-秒

通过Cookie实现登录状态记录，示例代码：

<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%@ page import="java.net.HttpCookie" %>
<%
   String path = request.getContextPath();
   String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
    <head>
        <!-- Page title -->
        <title>imooc - Login</title>
        <!-- End of Page title -->
        <!-- Libraries -->
        <link type="text/css" href="css/login.css" rel="stylesheet" />    
        <link type="text/css" href="css/smoothness/jquery-ui-1.7.2.custom.html" rel="stylesheet" />    
        <script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
        <script type="text/javascript" src="js/easyTooltip.js"></script>
        <script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script>
        <!-- End of Libraries -->    
    </head>
    <body>
    <%
        String username = "";
        String password = "";
        Cookie[] cookies = request.getCookies();
        if(cookies != null && cookies.length > 0){
            for(Cookie c:cookies){
                if(c.getName().equals("username")){
                    username = c.getValue();
                }
                if(c.getName().equals("password")){
                    password = c.getValue();
                }
            }
        }
    %>
    <div id="container">
        <div class="logo">
            <a href="#"><img src="assets/logo.png" alt="" /></a>
        </div>
        <div id="box">
            <form action="do_login.jsp" method="post">
            <p class="main">
                <label>用户名: </label>
                <input name="username" value="<%=username%>" />
                <label>密码: </label>
                <input type="password" name="password" value="<%=password%>">

            </p>

            <p class="space">
                <label>7天免登陆</label>
                <input type="checkbox" name="isUseCookie" checked="checked">
                <input type="submit" value="登录" class="login" style="cursor: pointer;"/>
            </p>
            </form>
        </div>
    </div>
    </body>
</html>

HTML-Login.jsp

<%@ page contentType="text/html;charset=UTF-8" %>
<jsp:useBean id="loginUser" class="com.po.Users" />
<jsp:useBean id="userDAO" class="com.dao.UsersDAO" />
<jsp:setProperty name="loginUser" property="*" />

<%
    // 如果用户名和密码都等于admin，则登录成功
    if(userDAO.usersLogin(loginUser)){
        session.setAttribute("loginUser", loginUser.getUsername());
        request.getRequestDispatcher("login_success.jsp").forward(request, response);
    }else {
        response.sendRedirect("login_failure.jsp");
    }
%>

HTML-doLogin.jsp

<%@ page import="java.net.HttpCookie" %><%--
  Created by IntelliJ IDEA.
  User: shongbing
  Date: 2019-01-05
  Time: 14:10
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <!-- Page title -->
    <title>imooc - Login</title>
    <!-- End of Page title -->
    <!-- Libraries -->
    <link type="text/css" href="css/login.css" rel="stylesheet" />
    <link type="text/css" href="css/smoothness/jquery-ui-1.7.2.custom.html" rel="stylesheet" />
    <script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
    <script type="text/javascript" src="js/easyTooltip.js"></script>
    <script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script>
    <!-- End of Libraries -->
</head>
<body>
<div id="container">
    <div class="logo">
        <a href="#"><img src="assets/logo.png" alt="" /></a>
    </div>
    <div id="box">
        <%
            String loginUser = "";
            if(session.getAttribute("loginUser") != null){
                loginUser = session.getAttribute("loginUser").toString();
            }

            String[] isUseCookies = request.getParameterValues("isUseCookie");
            if(isUseCookies != null && isUseCookies.length >0){
                // 把用户名和密码保存在Cookie对象中
                String username = request.getParameter("username");
                String password = request.getParameter("password");
                Cookie usernameCookie = new Cookie("username", username);
                Cookie passwordCookie = new Cookie("password", password);
                usernameCookie.setMaxAge(864000);
                passwordCookie.setMaxAge(864000);
                response.addCookie(usernameCookie);
                response.addCookie(passwordCookie);
            }else {
                Cookie[] cookies = request.getCookies();
                if(cookies != null && cookies.length > 0){
                    for(Cookie c:cookies){
                        if(c.getName().equals("username") || c.getName().equals("password")){
                            c.setMaxAge(0); // 设置Cookie失效
                            response.addCookie(c);  // 重新保存
                        }
                    }
                }
            }
        %>
        <a href="users.jsp" target="_blank">登录成功，查看用户信息</a>
    </div>
</div>
</body>
</html>

HTML-LoginSuccess.jsp

<%@ page import="java.net.HttpCookie" %><%--
  Created by IntelliJ IDEA.
  User: shongbing
  Date: 2019-01-06
  Time: 12:59
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>用户信息</title>
</head>
<body>
<h1>用户信息</h1><hr>
<%
    String username = "";
    String password = "";
    Cookie[] cookies = request.getCookies();
    if(cookies != null && cookies.length > 0){
        for(Cookie c:cookies){
            if(c.getName().equals("username")){
                username = c.getValue();
            }
            if(c.getName().equals("password")){
                password = c.getValue();
            }
        }
    }
%>
Username: <%=username %><br>
Password: <%=password %><br>

</body>
</html>