public class OrderCommandHandlers {

  @Autowired
  private OrderService orderService;

  public CommandHandlers commandHandlers() { ← 커맨드 메시지를 각각 적절한 핸들러 메서드로 라우팅
    return SagaCommandHandlersBuilder
      .fromChannel("orderService")
      .onMessage(ApproveOrderCommand.class, this::approveOrder)
      .onMessage(RejectOrderCommand.class, this::rejectOrder)
      ...
      .build();
  }

  public Message approveOrder(CommandMessage<ApproveOrderCommand> cm) {
    long orderId = cm.getCommand().getOrderId(); 
    OrderService.approveOrder(orderId);  ← Order를 승인 상태로 변경
    return withSuccess();  ← 제네릭 성공 메시지 반환
  }

  public Message rejectOrder(CommandMessage<RejectOrderCommand> cm) {
    long orderId = cm.getCommand().getOrderId();
    OrderService.rejectOrder(orderId); ← Order를 거부 상태로 변경
    return withSuccess();
  }