按id查询其他聚合根目录的CQRS+DDD命令端查询

public class GetUserOrdersCommand {
    private final String userId;

    public GetUserOrdersCommand(String userId) {
        this.userId = userId;
    }

    public String getUserId() {
        return userId;
    }
}

public class GetUserOrdersCommandHandler {
    private final OrderRepository orderRepository;

    public GetUserOrdersCommandHandler(OrderRepository orderRepository) {
        this.orderRepository = orderRepository;
    }

    public List<Order> handle(GetUserOrdersCommand command) {
        return orderRepository.findByUserId(command.getUserId());
    }
}

public interface OrderRepository {
    List<Order> findByUserId(String userId);
}

public class OrderService {
    private final GetUserOrdersCommandHandler commandHandler;

    public OrderService(GetUserOrdersCommandHandler commandHandler) {
        this.commandHandler = commandHandler;
    }

    public List<Order> getUserOrders(String userId) {
        GetUserOrdersCommand command = new GetUserOrdersCommand(userId);
        return commandHandler.handle(command);
    }
}