Java代码如何在建立连接后对数据库执行SQL查询

import java.sql.*;

public class DatabaseQuery {
    public static void main(String[] args) {
        // 数据库连接信息
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String username = "root";
        String password = "password";

        // 建立数据库连接
        try (Connection connection = DriverManager.getConnection(url, username, password)) {
            // 创建Statement对象
            Statement statement = connection.createStatement();

            // 执行SQL查询
            String sql = "SELECT * FROM mytable";
            ResultSet resultSet = statement.executeQuery(sql);

            // 处理查询结果
            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                System.out.println("ID: " + id + ", Name: " + name);
            }

            // 关闭结果集和Statement对象
            resultSet.close();
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}