验证码升级版

loginServlet

点击查看代码 
package servlet;

import javax.servlet.ServletContext;
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 java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置req编码
        req.setCharacterEncoding("utf-8");
        //获取参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String checkCode = req.getParameter("checkCode");

        HttpSession session = req.getSession();
        //每次登陆前就清除session缓存
        session.removeAttribute("cc_error");
        session.removeAttribute("up_error");
        //从session中获取正确验证码
        String check_code = (String) session.getAttribute("check_code");
//        System.out.println(checkCode);
//        System.out.println(check_code);
        session.removeAttribute("check_code");
        //判断
        if(check_code!=null && check_code.equalsIgnoreCase(checkCode)){

            //验证码正确
            //判断用户名和密码
            if(("lfqyj".equals(username))&&"123456".equals(password)){

                //登录成功
                //存储登录用户的信息
                session.setAttribute("success","恭喜你登陆成功！");
                session.setAttribute("s_username",username);
                //跳转到success.jsp,重定向
                String contextPath = req.getContextPath();
                resp.sendRedirect(contextPath+"/success.jsp");
            }else {
                //登陆失败
                //将提示信息存到session中
                session.setAttribute("up_error","用户名或密码错误");
                //转发到登录页
                req.getRequestDispatcher("/login.jsp").forward(req,resp);
            }
        }else{
            session.removeAttribute("check_code");
            //将提示信息存到session中
            session.setAttribute("cc_error","验证码错误");
            //转发到登录页
            req.getRequestDispatcher("/login.jsp").forward(req,resp);
        }


    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }
}
login.jsp
点击查看代码 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>login</title>
</head>
<body>
    <form action="/Spring_MVC/loginServlet" method="post">
        <table>
            <tr>
                <td>用户名</td>
                <td><input type="text" name="username"></td>
            </tr>
            <tr>
                <td>密码</td>
                <td><input type="password" name="password"></td>
            </tr>
            <tr>
                <td>验证码</td>
                <td><input type="text" name="checkCode"></td>
            </tr>
            <tr>
                <td colspan="2"><img id="img" src="/Spring_MVC/CheckCodeServlet"></td>
            </tr>
            <tr>
                <td><input type="submit" name="登录"></td>
            </tr>

        </table>

    </form>
    <div style="color: red"><%=request.getSession().getAttribute("cc_error")==null? "":request.getSession().getAttribute("cc_error")%></div>

    <div style="color: red"><%=request.getSession().getAttribute("up_error")==null? "":request.getSession().getAttribute("up_error")%></div>

</body>
<script>
    window.onload= function () {
        var img = document.getElementById("img");
        img.onclick = function () {
            //加时间戳
            var date = new Date().getTime();
            img.src = "/Spring_MVC/CheckCodeServlet?" + date;


            // 清除错误信息显示
            var errorDivs = document.querySelectorAll("div[style='color: red']");
            errorDivs.forEach(function (div) {
                div.innerHTML = "";
            });
        };

        // 当用户开始输入时清除对应错误信息
        document.querySelector("input[name='checkCode']").oninput = function () {
            document.querySelector("div[style='color: red']").innerHTML = "";
        };

    };
</script>
</html>
success.jsp
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<%--
  Created by IntelliJ IDEA.
  User: ASUS
  Date: 2025/5/29
  Time: 22:33
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>success</title>
</head>
<body>
    <h1><%=request.getSession().getAttribute("s_username")%>，欢迎！</h1>
</body>
</html>
posted @ 2025-05-29 23:41  lfqyj  阅读(6)  评论(0)    收藏  举报