Java org.json JDBC数据库中只有最后一行表行

import org.json.JSONArray;
import org.json.JSONObject;

import java.sql.*;

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

        try {
            // 连接数据库
            Connection connection = DriverManager.getConnection(url, username, password);

            // 执行查询语句
            String query = "SELECT * FROM mytable";
            PreparedStatement statement = connection.prepareStatement(query);
            ResultSet resultSet = statement.executeQuery();

            // 将结果集转换为JSONArray
            JSONArray jsonArray = new JSONArray();
            while (resultSet.next()) {
                JSONObject jsonObject = new JSONObject();
                jsonObject.put("column1", resultSet.getString("column1"));
                jsonObject.put("column2", resultSet.getString("column2"));
                // 添加更多列...

                jsonArray.put(jsonObject);
            }

            // 处理JSONArray中的数据
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                // 处理每一行的数据
                String column1Value = jsonObject.getString("column1");
                String column2Value = jsonObject.getString("column2");
                // 处理更多列的数据...
            }

            // 关闭连接
            resultSet.close();
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}