cookie实现多少天免登录

最新推荐文章于 2024-07-31 04:30:46 发布

Saltwater_leo

最新推荐文章于 2024-07-31 04:30:46 发布

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CC 4.0 BY-SA版权

分类专栏： jsp

本文链接：https://blog.youkuaiyun.com/liuao107329/article/details/41045929

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本文详细阐述了基于HTTP Cookie的用户登录验证流程，并通过Java Servlet实现登录表单提交处理，确保用户身份的安全性和持久性。

<%@page import="java.util.Arrays"%>
<%@page import="com.leo.model.User"%>
<%@ 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>	

<%--查找本地有没有对应 “用户和密码”的cookie --%>
	<%
		Cookie [] cos = request.getCookies();
	
		if(cos!=null){
			
			for(Cookie co :cos){
				
				if(co.getName().equals("cookie_usermsg")){
					
					String[] values =co.getValue().split("&");
					
					
					System.out.println(Arrays.toString(values));
					
					String username = values[0];
					String password = values[1];
					
					if(username.equals("leo")&&password.equals("123")){
						
						User user = new User(username,password);
						
						session.setAttribute("user", user);
						
						request.getRequestDispatcher("main.jsp").forward(request, response);
					}else{
						request.setAttribute("errormsg", "用户名密码错误");
					}
					
				}
				
			}	
			
		}
	
	%>
	
	<%--登陆表单 --%>
	<form action="cookieservlet" method="post">
	
		用户名:<input type="text"  name="username" /><br/>
		密码:<input type="password" name="password"  /><br/>
		<input type="checkbox" name="time"  />1天内免登录<br/>
		
		<% 
			String errormsg = (String)request.getAttribute("errormsg");
			if(errormsg!=null){
		%>	
				<span style="color: red"><%=errormsg %></span><br>
		<%
			}
		%>
		<input type="submit" value="提交" />
	</form>

</body>
</html>

——————————————————————————————————————————————————————————————————

表单提交到servlet服务器

package com.leo.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.leo.model.User;


public class CookieServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		request.setCharacterEncoding("utf-8");
		
		String username = request.getParameter("username");
		String password = request.getParameter("password");
		
		if(username.equals("leo")&&password.equals("123")){
			
			User user = new User(username, password);
			
			HttpSession session = request.getSession();
			session.setAttribute("user", user);
			
			String time = request.getParameter("time");
			
			if(time!=null){
				
				Cookie co = new Cookie("cookie_usermsg", username+"&"+password);
				co.setMaxAge(86400);
				response.addCookie(co);
					
			}
			//这里跳转要使用客户端跳转，因为要到客户端取cookie，服务器跳转的话中间就不会经过客户端
			response.sendRedirect("main.jsp");

		}else{
			
			request.setAttribute("errormsg", "用户名或密码错误");
			request.getRequestDispatcher("login.jsp").forward(request, response);
		}
			
	}
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
		
	}

}
———————————————————————————————————————————————————————— 
<span style="color:#990000;">登录成功后的页面</span>
<pre name="code" class="html"><%@page import="com.leo.model.User"%>
<%@ 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>
	<%
		User user = (User)session.getAttribute("user");
	%>
	
	用户名:<%=user.getUsername() %>
	
</body>
</html>