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@nalan90 2018-06-29T03:16:18.000000Z 字数 2539 阅读 695

四、JSP状态管理

JAVAEE开发

内容列表
# 保存用户状态的两大机制
JSP中创建与使用Cookie
  1. Cookie cookie = new Cookie(String key, Object value);
  1. response.addCookie(cookie);
  1. Cookie[] cookies = request.getCookies();
  1. ## login.jsp
  2. <%@ page contentType="text/html;charset=UTF-8" import="java.net.*" language="java" %>
  3. <html>
  4. <head>
  5.     <title>登录页面</title>
  6. </head>
  7. <body>
  8. <%
  9.     String username = "";
  10.     String password = "";
  12.     Cookie[] cookies = request.getCookies();
  13.     if (cookies != null && cookies.length > 0) {
  14.         for (Cookie c: cookies) {
  15.             if (c.getName().equals("username")) {
  16.                 username = URLDecoder.decode(c.getValue(),"utf-8");
  17.             }
  18.             if (c.getName().equals("password")) {
  19.                 password = c.getValue();
  20.             }
  21.         }
  22.     }
  23. %>
  24.     <h1>用户登录</h1>
  25.     <hr>
  26.     <form action="dologin.jsp" name="loginForm" method="post">
  27.         用户名: <input type="text" name="username" value="<%=username%>"><br>
  28.         密码：<input type="password" name="password" value="<%=password%>"><br>
  29.         <input type="checkbox" name="isUseCookie" checked="checked">十天内记住我的登录状态<br>
  30.         <input type="submit" value="login">
  31.     </form>
  32. </body>
  33. </html>
  35. ## dologin.jsp
  36. <%@ page contentType="text/html;charset=UTF-8" import="java.net.*" language="java" %>
  37. <%
  38.     request.setCharacterEncoding("utf-8");
  39. %>
  40. <%
  41.    String[] isUseCookies = request.getParameterValues("isUseCookie");
  43.    if (isUseCookies != null && isUseCookies.length > 0) {
  44.        String username = URLEncoder.encode(request.getParameter("username"),"utf-8");
  45.        String password = request.getParameter("password");
  47.        Cookie nameCookie = new Cookie("username", username);
  48.        Cookie passwordCookie = new Cookie("password", password);
  49.        nameCookie.setMaxAge(600);
  50.        passwordCookie.setMaxAge(600);
  51.        response.addCookie(nameCookie);
  52.        response.addCookie(passwordCookie);
  53.    } else {
  54.        Cookie[] cookies = request.getCookies();
  55.        if (cookies != null && cookies.length > 0) {
  56.            for (Cookie c: cookies) {
  57.                if (c.getName().equals("username") || c.getName().equals("password")) {
  58.                    c.setMaxAge(0);
  59.                    response.addCookie(c);
  60.                }
  61.            }
  62.        }
  63.    }
  64. %>
  65. <a href="users.jsp">查看用户信息</a>
  67. ## users.jsp
  68. <%@ page contentType="text/html;charset=UTF-8" import="java.net.*" language="java" %>
  69. <html>
  70. <head>
  71.     <title>Title</title>
  72. </head>
  73. <body>
  75. <%
  76.     String username = "";
  77.     String password = "";
  79.     Cookie[] cookies = request.getCookies();
  80.     if (cookies != null && cookies.length > 0) {
  81.         for (Cookie c: cookies) {
  82.             if (c.getName().equals("username")) {
  83.                 username = URLDecoder.decode(c.getValue(),"utf-8");
  84.             }
  85.             if (c.getName().equals("password")) {
  86.                 password = c.getValue();
  87.             }
  88.         }
  89.     }
  90. %>
  91. <br>
  92. 用户名: <%=username%><br>
  93. 密码: <%=password%>
  94. </body>
  95. </html>
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