使用Cookie儲存使用者登入狀態
阿新 • • 發佈：2019-02-16
1.login.jsp：實現登入介面，使用者可以設定Cooike生存期
<%@ 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+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'login.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 rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <% request.setCharacterEncoding("UTF-8"); Cookie[] cookies = request.getCookies(); String username =""; String password =""; 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"); } } } %> <h1>使用者登入</h1> <hr> <form name="LoginForm" action="doLogin.jsp" method="post"> <table> <tr> <td>使用者名稱：</td> <td><input type="text" name="username" value="<%=username %>"></td> </tr> <tr> <td>密碼：</td> <td><input type="password" name="password" value="<%=password%>"></td> </tr> <tr> <td colspan="2" align="center"><input type="checkbox" name="isUseCookie" checked="checked">十天內記住我的登入狀態</td> </tr> <tr> <td colspan="2" align="center"><input type="submit" value="登入"><input type="reset" value="取消"></td> </tr> </table> </form> </body> </html>
2.dologin.jsp：通過request物件獲取使用者名稱和密碼並將其儲存在Cookie中
<%@ 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+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=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 rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> 登入成功<br> <% request.setCharacterEncoding("utf-8"); //首先判斷使用者是否選擇了記住登入狀態 String[] isUseCookies = request.getParameterValues("isUseCookie"); if(isUseCookies!=null&&isUseCookies.length>0){ String username =URLEncoder.encode(request.getParameter("username"), "utf-8") ; String password =URLEncoder.encode(request.getParameter("password"), "utf-8") ;//使用URLEncoder解決無法在Cookie當中儲存中文字串問題 Cookie usernameCookie = new Cookie("username",username);//把使用者名稱和密碼都儲存在Cookie裡面 Cookie passwordCookie = new Cookie("password",password); usernameCookie.setMaxAge(864000);//設定最大生存期限為10天 passwordCookie.setMaxAge(864000); response.addCookie(usernameCookie);//將Cookie儲存在response物件中 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);//設定Cookie失效 response.addCookie(c);//重新儲存 } } } } %> <br> <a href="users.jsp">檢視使用者資訊</a> </body> </html>
3.user.jsp：讀取Cooike中的使用者名稱和密碼並顯示出來
<%@page import="java.net.URLDecoder"%> <%@ 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+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP '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 rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <h1>使用者資訊</h1> <% request.setCharacterEncoding("UTF-8"); Cookie[] cookies = request.getCookies(); String username =""; String password =""; 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"); } } } %> 使用者名稱：<%=username %> <br> 密 碼：<%=password %> </body> </html>