利用session在html和MySQL实现登录

首先先创建一个登录页面（login.html）

html 复制代码

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script src="js/jquery-3.7.1.min.js"></script>
<script src="js/jquery.cookie.min.js"></script>
<script src="js/login.js" defer></script>
</head>
<body>

	<div>
		账号：<input type='text' class='account'><br>
		密码：<input type='text' class='password'><br>
		<input type='button' value='登录' class='btn'> 
	</div>
</body>
</html>

并且在相对应的位置上创建js文件

javascript 复制代码

$(".btn").on("click",function(){
	var account = $(".account").val().trim()
	var password = $(".password").val().trim()
	$.ajax({
		url:"Studentlogin",
		type:"get",
		data:{
			account,
			password,
			/*captcha*/
		},
		success:function(value){
			alert(value)
			if(value=="登录成功"){
				location.href="student.html"
			}
		}
	})
})

if(value=="登录成功"){

location.href="student.html"

}判断登录成功之后跳转的页面

在创建一个相应的servlet文件（Studentlogin.java）

java 复制代码

package qcby.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import qcby.db.MysqlUtil;

/**
 * Servlet implementation class Login
 */
@WebServlet("/Studentlogin")
public class Studentlogin extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Studentlogin() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String account = request.getParameter("account");
		String password = request.getParameter("password");
		String captcha = request.getParameter("captcha");
		HttpSession session = request.getSession();
		String captchaVal = (String)session.getAttribute("captchaVal");
		String res = "验证码错误";
		if(captcha.equals(captchaVal)) {
			String sql = "select count(*) from admin where account=\""+account+"\" and password=\""+password+"\"";
			int num = MysqlUtil.getCount(sql);
			res = "登录失败";
			if(num>0) {
				res = "登录成功";
				//设置登录状态
				session.setAttribute("account", account);
			}
		}
		request.setCharacterEncoding("utf-8");
	    response.setCharacterEncoding("utf-8");
	    response.getWriter().write(res);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

这样就能够利用session进行登录判断了