JSP的Cookie在登录中的使用
一 功能需求
实现记忆用户名和密码功能。
二 代码
1、login.jsp
<%@ page language="java" import="java.util.*,java.net.*" contentType="text/html; charset=utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"https://www.jb51.net/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="https://www.jb51.net/<%=basePath%>" > <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link type="text/css" href="https://www.jb51.net/styles.css" > --> </head> <body> <h1>用户登录</h1> <hr> <% request.setCharacterEncoding("utf-8"); String username=""; String password = ""; Cookie[] cookies = request.getCookies(); if(cookies!=null&&cookies.length>0) { for(Cookie c:cookies) { 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" value="<%=username %>"/></td> </tr> <tr> <td>密码：</td> <td><input type="password" value="<%=password %>" /></td> </tr> <tr> <td colspan="2"><input type="checkbox" checked="checked"/>十天内记住我的登录状态</td> </tr> <tr> <td colspan="2"><input type="submit" value="登录"/><input type="reset" value="取消"/></td> </tr> </table> </form> </body> </html>
2、dologin.jsp
<%@ page language="java" import="java.util.*,java.net.*" contentType="text/html; charset=utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"https://www.jb51.net/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="https://www.jb51.net/<%=basePath%>" > <title>My JSP 'dologin.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link type="text/css" href="https://www.jb51.net/styles.css" > --> </head> <body> <h1>登录成功</h1> <hr> <br> <br> <br> <% request.setCharacterEncoding("utf-8"); //首先判断用户是否选择了记住登录状态 String[] isUseCookies = request.getParameterValues("isUseCookie"); if(isUseCookies!=null&&isUseCookies.length>0) { //把用户名和密码保存在Cookie对象里面 String username = URLEncoder.encode(request.getParameter("username"),"utf-8"); //使用URLEncoder解决无法在Cookie当中保存中文字符串问题 String password = URLEncoder.encode(request.getParameter("password"),"utf-8"); Cookie usernameCookie = new Cookie("username",username); Cookie passwordCookie = new Cookie("password",password); usernameCookie.setMaxAge(864000); passwordCookie.setMaxAge(864000);//设置最大生存期限为10天 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="https://www.jb51.net/users.jsp" target="_blank">查看用户信息</a> </body> </html>
3、users.jsp
<%@ page language="java" import="java.util.*,java.net.*" contentType="text/html; charset=utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"https://www.jb51.net/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="https://www.jb51.net/<%=basePath%>" > <title>My JSP 'https://www.jb51.net/users.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link type="text/css" href="https://www.jb51.net/styles.css" > --> </head> <body> <h1>用户信息</h1> <hr> <% request.setCharacterEncoding("utf-8"); String username=""; String password = ""; Cookie[] cookies = request.getCookies(); if(cookies!=null&&cookies.length>0) { for(Cookie c:cookies) { if(c.getName().equals("username")) { username = URLDecoder.decode(c.getValue(),"utf-8"); } if(c.getName().equals("password")) { password = URLDecoder.decode(c.getValue(),"utf-8"); } } } %> <BR> <BR> <BR> 用户名：<%=username %><br> 密码：<%=password %><br> </body> </html>
三 测试
