java web连接mysql

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class MySQLConnectionExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String username = "root";
        String password = "password";

        try {
            // 加载 JDBC 驱动程序
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 建立数据库连接
            Connection connection = DriverManager.getConnection(url, username, password);

            // 执行查询
            String sql = "SELECT * FROM users WHERE username = ?";
            PreparedStatement pstmt = connection.prepareStatement(sql);
            pstmt.setString(1, "admin");
            ResultSet rs = pstmt.executeQuery();

            // 处理结果集
            while (rs.next()) {
                System.out.println("User ID: " + rs.getInt("id"));
                System.out.println("Username: " + rs.getString("username"));
            }

            // 关闭连接
            rs.close();
            pstmt.close();
            connection.close();
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
    }
}