如何在java中保留从varchar值中获取的中文/韩文字符

import java.sql.*;

public class Main {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/db_name?characterEncoding=utf8";
        String username = "username";
        String password = "password";

        try {
            // 设置默认字符集为UTF-8
            System.setProperty("file.encoding", "UTF-8");

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

            // 执行查询语句
            Statement statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery("SELECT column_name FROM table_name");

            // 获取varchar值并进行解码
            while (resultSet.next()) {
                String value = resultSet.getString("column_name");
                String decodedValue = new String(value.getBytes("ISO-8859-1"), "UTF-8");
                System.out.println(decodedValue);
            }

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