JSP中Cookie在登录功能中的简单应用

文章目录[隐藏]

代码如下

代码如下

login.jsp

<%@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>用户登录</h1>
<%
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″);//解码
}
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”/>10 天记住登录
</td>
</tr>
<tr>
<td clospan=“2”>
<input type=“submit” value=“登录”/>
</td>
</tr>
</table>
</form>
</body>
</html>

doLogin.jsp

<%@page import=“java.net.URLEncoder”%>
<%@ 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>登录成功</h1>
<br />
<%
request.setCharacterEncoding(“utf-8”);
//首先判断用户是否选择了记住登录选项
String[] isUseCookies = request.getParameterValues(“isUseCookie”);
if(isUseCookies!=null &&isUseCookies.length>0) {
//把用户名和密码保存在 Cookie 里面
//使用 URLEncoder 解决无法在 Cookie 中保存中文字符串问题
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);
response.addCookie(usernameCookie);
response.addCookie(passwordCookie);
usernameCookie.setMaxAge(864000);//设置最大生存期限为 10 天
passwordCookie.setMaxAge(864000);
} 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”>查看用户信息</a>
</body>
</html>

users.jsp

<%@page import=“java.net.URLDecoder”%>
<%@page import=“org.apache.tomcat.util.http.Cookies”%>
<%@ 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</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 = URLDecoder.decode(c.getValue(),”utf-8″);//解码
}
if(c.getName().equals(“password”)) {
password = URLDecoder.decode(c.getValue(),”utf-8″);
}
}
}
%>
用户名：<%=username %> <br />
密码： <%=password %> <br />
</body>
</html>

代码如下

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