jsp连接数据库实现登陆注册

首先需要在JSP中导入JDBC驱动，然后建立数据库连接。可以按照以下步骤实现：

1. 导入JDBC驱动

<%@ page import="java.sql.*" %>

2. 建立数据库连接

String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
String username = "root";
String password = "root";

Connection conn = null;
try {
    Class.forName(driver);
    conn = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
    e.printStackTrace();
}

3. 实现用户注册

String username = request.getParameter("username");
String password = request.getParameter("password");

PreparedStatement pstmt = null;
String sql = "insert into user(username, password) values(?, ?)";
try {
    pstmt = conn.prepareStatement(sql);
    pstmt.setString(1, username);
    pstmt.setString(2, password);
    pstmt.executeUpdate();
} catch (Exception e) {
    e.printStackTrace();
} finally {
    try {
        pstmt.close();
        conn.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

4. 实现用户登录

String username = request.getParameter("username");
String password = request.getParameter("password");

PreparedStatement pstmt = null;
ResultSet rs = null;
String sql = "select * from user where username=? and password=?";
try {
    pstmt = conn.prepareStatement(sql);
    pstmt.setString(1, username);
    pstmt.setString(2, password);
    rs = pstmt.executeQuery();
    if (rs.next()) {
        // 登录成功
    } else {
        // 登录失败
    }
} catch (Exception e) {
    e.printStackTrace();
} finally {
    try {
        rs.close();
        pstmt.close();
        conn.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

以上代码仅供参考，具体实现需要根据具体情况进行调整。