不会做，找个好心人帮做，有偿，只要答案
呃…百度有很多吖
这个一搜一大堆，像这样的
望采纳
下面是一个示例 Java web 项目，它实现了一个管理员登录页面。
首先，需要导入 xanke.sql 数据库，它包含一个名为 "admin" 的表，用于存储管理员信息。
然后，创建一个 Java web 项目，并在项目中创建一个名为 "login.jsp" 的文件，用于显示登录表单。
login.jsp 中的代码如下所示：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>管理员登录</title>
</head>
<body>
<form action="login" method="post">
<label for="username">用户名:</label> <input type="text"
name="username" id="username" /> <br /> <label for="password">密码:</label>
<input type="password" name="password" id="password" /> <br /> <input
type="submit" value="登录" />
</form>
</body>
</html>
接下来，需要创建一个名为 "login" 的 Servlet 类，用于处理登录表单的提交请求。Servlet 类的代码如下所示：
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/login")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/xanke", "root", "");
PreparedStatement ps = conn.prepareStatement("SELECT * FROM admin WHERE username = ? AND password = ?");
ps.setString(1, username);
ps.setString(2, password);
ResultSet rs = ps.executeQuery();
if (rs.next()) {
// 登录成功，跳转到管理员主页
response.sendRedirect("admin.jsp");
} else {
// 登录失败，跳转到登录页面，并显示错误消息
response.sendRedirect("login.jsp?error=true");
}
} catch (ClassNotFoundException | SQLException e) {
throw new ServletException(e);
}
}
}
最后，在 login.jsp 页面中添加一个判断，用于在登录失败时显示错误消息：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>管理员登录</title>
</head>
<body>
<%
String error = request.getParameter("error");
if (error != null) {
%>
<p>用户名或密码错误，请重新登录。</p>
<%
}
%>
<form action="login" method="post">
<label for="username">用户名:</label> <input type="text"
name="username" id="username" /> <br /> <label for="password">密码:</label>
<input type="password" name="password" id="password" /> <br /> <input
type="submit" value="登录" />
</form>
</body>
</html>
这样，就可以在登录失败时向用户显示错误消息了。
提供一个漂亮又美观的实例【用jsp实现简单登入注册界面功能（css美化）（软件idea）】，链接：https://blog.csdn.net/aasd23/article/details/123722532?spm=1001.2101.3001.6650.6&utm_medium=distribute.pc_relevant.none-task-blog-2%7Edefault%7EBlogCommendFromBaidu%7ERate-6-123722532-blog-123074186.pc_relevant_default&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2%7Edefault%7EBlogCommendFromBaidu%7ERate-6-123722532-blog-123074186.pc_relevant_default&utm_relevant_index=13
【博文讲解详细，注解清晰，登录页面也赋予了美化，更加漂亮】
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<html>
<head>
</head>
<body>
<form action="shoppingLogin" method="post">
用户名：
<input type="text" name="uname">
<br>
密码：
<input type="password" name="upass">
<br>
<input type="submit" value="登陆">
</body>
</html>
package loginsev;
import java.io.IOException;
import java.util.ArrayList;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.yangjuzhi.bean.User;
import org.yangjuzhi.pojo.Methods;
public class shoppingLogin extends HttpServlet {
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
response.setCharacterEncoding("gb2312");
String uname=request.getParameter("uname");
String upass=request.getParameter("upass");
Methods md=new Methods();
User user=new User();
user.setU_name(uname);
user.setU_pwd(upass);
boolean b=md.successLogin(user);
if(b){
ArrayList al=md.getAllInfo();
request.getSession().setAttribute("list",al);
request.getRequestDispatcher("index.jsp").forward(request, response);
}else{
request.getRequestDispatcher("errow.jsp").forward(request, response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}
Javaweb登录页面的实现详细步骤都有
如有帮助，望采纳
https://blog.csdn.net/weixin_45757641/article/details/120112493