```java
<%@ page import="java.sql.Connection" %>
<%@ page import="com.anbow.jsp.DBUtils" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.Statement" %><%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2019/10/22
Time: 19:35
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<%
//获取数据
String idcard = request.getParameter("username");
String password = request.getParameter("password");
//连接数据库
Connection connection = DBUtils.getConnection();
String sql="select * from login where username = ? and password = ?";
PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1,idcard);
preparedStatement.setString(2,password);
ResultSet rs= preparedStatement.executeQuery();
//遍历
if (rs.next()){
//存在则页面跳转
request.getRequestDispatcher("index.jsp").forward(request, response);
}else{
//(失败，信息不存在 跳转到首页，相当于重置数据)
request.getRequestDispatcher("login.jsp").forward(request, response);
//保存{这不知道哪里错了，没效果！}
request.setAttribute("error","<script>alert('错误);</script>");
}
//关闭
connection.close();
rs.close();
preparedStatement.close();
out.clear();
out = pageContext.pushBody();
%>
</body>
</html>
