【架构实战】六边形架构与整洁架构实战

一、架构演进概述随着业务复杂度增加软件架构也在不断演进架构演进历程分层架构 → 六边形架构 → 整洁架构 → 微服务架构核心目标实现高内聚、低耦合架构质量评估独立性框架、数据库、UI的可替换性可测试性业务逻辑可独立测试可维护性代码易于理解和修改二、六边形架构Hexagonal Architecture1. 核心理念六边形架构又称端口与适配器Ports and Adapters由Alistair Cockburn提出。 核心思想 - 业务逻辑处于核心位置 - 通过端口与外部世界交互 - 适配器负责协议转换2. 架构图┌─────────────────────────────────┐ │ 外部世界 │ │ (数据库、Web UI、外部服务) │ └─────────────┬───────────────────┘ │ ┌─────────────▼───────────────────┐ │ 适配器层 │ │ ┌─────────────┬─────────────┐ │ │ │ 驱动适配器 │ 驱动适配器 │ │ │ │ (Primary) │ (Primary) │ │ │ └──────┬──────┴──────┬──────┘ │ └─────────┼─────────────┼────────┘ │ │ ┌─────────▼─────────────▼─────────┐ │ 端口层 │ │ (输入端口) (输出端口) │ │ ┌─────────────┬─────────────┐ │ │ │ │ │ │ │ └──────┬──────┴──────┬──────┘ │ └─────────┼─────────────┼────────┘ │ │ ┌─────────▼─────────────▼─────────┐ │ 应用层 │ │ (用例/服务编排) │ └─────────┬─────────────────────┘ │ ┌─────────▼─────────────────────┐ │ 领域层 │ │ (核心业务逻辑、实体、值对象) │ └─────────────────────────────────┘3. 核心概念端口Port定义了系统与外部交互的方式分为输入端口驱动端口和输出端口被驱动端口端口是接口不包含实现适配器Adapter负责实现端口定义的接口处理外部协议和格式转换适配器可以随时替换4. 代码实现领域层核心// 领域实体publicclassOrder{privateOrderIdid;privateCustomerIdcustomerId;privateOrderStatusstatus;privateListOrderItemitems;publicvoidaddItem(Productproduct,intquantity){if(status!OrderStatus.DRAFT){thrownewBusinessException(只有草稿状态可以添加商品);}items.add(newOrderItem(product,quantity));}publicvoidsubmit(){if(items.isEmpty()){thrownewBusinessException(订单不能为空);}this.statusOrderStatus.SUBMITTED;}}// 领域服务publicclassOrderDomainService{publicvoidvalidateOrder(Orderorder){// 业务规则验证}}输入端口Driving Port// 输入端口接口由应用层或领域层定义publicinterfaceOrderInputPort{OrderDTOcreateOrder(CreateOrderCommandcommand);OrderDTOupdateOrder(LongorderId,UpdateOrderCommandcommand);voidcancelOrder(LongorderId);OrderDTOgetOrder(LongorderId);PageOrderDTOlistOrders(OrderQueryquery);}输出端口Driven Port// 输出端口接口由应用层定义由基础设施实现publicinterfaceOrderRepository{OrderfindById(OrderIdid);Ordersave(Orderorder);voiddelete(OrderIdid);}publicinterfaceProductRepository{ProductfindById(ProductIdid);ListProductfindByIds(ListProductIdids);}publicinterfaceEventPublisher{voidpublish(DomainEventevent);}publicinterfaceIdGenerator{OrderIdgenerateId();}应用层用例// 应用服务实现输入端口ServiceTransactionalpublicclassOrderApplicationServiceimplementsOrderInputPort{privatefinalOrderRepositoryorderRepository;privatefinalProductRepositoryproductRepository;privatefinalIdGeneratoridGenerator;privatefinalEventPublishereventPublisher;publicOrderApplicationService(OrderRepositoryorderRepository,ProductRepositoryproductRepository,IdGeneratoridGenerator,EventPublishereventPublisher){this.orderRepositoryorderRepository;this.productRepositoryproductRepository;this.idGeneratoridGenerator;this.eventPublishereventPublisher;}OverridepublicOrderDTOcreateOrder(CreateOrderCommandcommand){// 创建订单OrderorderOrder.create(idGenerator.generateId(),CustomerId.of(command.getCustomerId()));// 添加商品for(OrderItemDTOitemDTO:command.getItems()){ProductproductproductRepository.findById(ProductId.of(itemDTO.getProductId()));order.addItem(product,itemDTO.getQuantity());}// 提交订单order.submit();// 保存orderRepository.save(order);// 发布事件eventPublisher.publish(newOrderCreatedEvent(order));returntoDTO(order);}}适配器层// Web适配器Driving AdapterRestControllerpublicclassOrderControllerimplementsOrderInputPort{privatefinalOrderApplicationServiceorderService;PostMapping(/orders)publicResponseEntityOrderDTOcreateOrder(RequestBodyCreateOrderRequestrequest){CreateOrderCommandcommandtoCommand(request);OrderDTOresultorderService.createOrder(command);returnResponseEntity.ok(result);}// ... 其他接口方法}// JPA适配器Driven AdapterRepositorypublicclassJpaOrderRepositoryimplementsOrderRepository{AutowiredprivateOrderJpaRepositoryjpaRepository;OverridepublicOrderfindById(OrderIdid){returnjpaRepository.findById(id.getValue()).map(this::toDomain).orElseThrow(()-newEntityNotFoundException(Order not found));}OverridepublicOrdersave(Orderorder){OrderEntityentitytoEntity(order);jpaRepository.save(entity);returnorder;}}// 消息适配器Driven AdapterComponentpublicclassKafkaEventPublisherimplementsEventPublisher{AutowiredprivateKafkaTemplateString,ObjectkafkaTemplate;Overridepublicvoidpublish(DomainEventevent){kafkaTemplate.send(domain-events,event.getClass().getSimpleName(),event);}}// UUID适配器Driven AdapterComponentpublicclassUuidIdGeneratorimplementsIdGenerator{OverridepublicOrderIdgenerateId(){returnOrderId.of(UUID.randomUUID().toString());}}三、整洁架构Clean Architecture1. 核心理念整洁架构由Robert C. Martin提出强调 - 依赖规则外层依赖内层内层不知道外层 - 层次分离明确的职责边界 - 独立性强业务逻辑不依赖任何外部框架2. 架构层次┌─────────────────────────────────────────────────────────────────┐ │ 外层框架 驱动 │ │ (Web框架、数据库、UI、外部接口、测试框架) │ ├─────────────────────────────────────────────────────────────────┤ │ 接口适配器层 │ │ (Controllers、Gateways、Presenters) │ ├─────────────────────────────────────────────────────────────────┤ │ 应用层 │ │ (用例、命令、查询、DTO) │ ├─────────────────────────────────────────────────────────────────┤ │ 领域层 │ │ (实体、值对象、领域服务、领域事件、接口) │ ├─────────────────────────────────────────────────────────────────┤ │ 内层企业业务规则 │ └─────────────────────────────────────────────────────────────────┘ ▲ │ 依赖方向 │ ▼3. 依赖规则依赖规则Dependency Rule - 源码依赖只能从外向内 - 内层不知道外层的存在 - 外层通过接口依赖内层 - 具体的实现细节放在外层4. 代码结构com.example.cleanarchitecture ├── domain # 领域层最内层 │ ├── model │ │ ├── Order.java │ │ ├── Product.java │ │ └── Customer.java │ ├── service │ │ └── OrderDomainService.java │ ├── event │ │ └── DomainEvent.java │ └── port # 端口接口 │ ├── inbound │ │ ├── CreateOrderUseCase.java │ │ └── OrderQueryService.java │ └── outbound │ ├── OrderRepository.java │ ├── ProductRepository.java │ └── EventPublisher.java ├── application # 应用层 │ ├── usecase │ │ ├── CreateOrderUseCaseImpl.java │ │ └── GetOrderUseCaseImpl.java │ ├── dto │ │ ├── CreateOrderCommand.java │ │ └── OrderDTO.java │ └── mapper │ └── OrderMapper.java ├── adapter # 适配器层 │ ├── inbound │ │ ├── web │ │ │ └── OrderController.java │ │ └── grpc │ │ └── OrderGrpcAdapter.java │ └── outbound │ ├── persistence │ │ ├── JpaOrderRepository.java │ │ └── JpaProductRepository.java │ ├── messaging │ │ └── KafkaEventPublisher.java │ └── external │ └── PaymentGatewayAdapter.java └── configuration # 配置层 └── DependencyInjectionConfig.java5. 整洁架构实现领域层// 领域实体publicclassOrder{privateOrderIdid;privateCustomerIdcustomerId;privateOrderStatusstatus;privateListOrderItemitems;publicstaticOrdercreate(OrderIdid,CustomerIdcustomerId){returnnewOrder(id,customerId,OrderStatus.DRAFT,newArrayList());}publicvoidaddItem(Productproduct,intquantity){// 业务规则if(status!OrderStatus.DRAFT){thrownewDomainException(只有草稿订单可以添加商品);}items.add(newOrderItem(product,quantity));}}// 输入端口用例接口publicinterfaceCreateOrderUseCase{OrderDTOexecute(CreateOrderCommandcommand);}// 输出端口仓储接口publicinterfaceOrderRepository{OptionalOrderfindById(OrderIdid);Ordersave(Orderorder);voiddelete(OrderIdid);ListOrderfindByCustomerId(CustomerIdcustomerId);}应用层// 用例实现ServicepublicclassCreateOrderUseCaseImplimplementsCreateOrderUseCase{privatefinalOrderRepositoryorderRepository;privatefinalProductRepositoryproductRepository;privatefinalIdGeneratoridGenerator;publicCreateOrderUseCaseImpl(OrderRepositoryorderRepository,ProductRepositoryproductRepository,IdGeneratoridGenerator){this.orderRepositoryorderRepository;this.productRepositoryproductRepository;this.idGeneratoridGenerator;}OverridepublicOrderDTOexecute(CreateOrderCommandcommand){// 1. 验证客户CustomerIdcustomerIdCustomerId.of(command.getCustomerId());// 2. 创建订单OrderIdorderIdidGenerator.generateId();OrderorderOrder.create(orderId,customerId);// 3. 添加商品for(OrderItemCommanditemCmd:command.getItems()){ProductproductproductRepository.findById(ProductId.of(itemCmd.getProductId())).orElseThrow(()-newDomainException(商品不存在));order.addItem(product,itemCmd.getQuantity());}// 4. 提交订单order.submit();// 5. 保存orderRepository.save(order);// 6. 返回DTOreturnOrderDTO.from(order);}}适配器层// Web控制器入站适配器RestControllerRequestMapping(/api/orders)publicclassOrderController{privatefinalCreateOrderUseCasecreateOrderUseCase;privatefinalGetOrderUseCasegetOrderUseCase;PostMappingpublicResponseEntityOrderDTOcreateOrder(RequestBodyValidCreateOrderRequestrequest){CreateOrderCommandcommandCreateOrderCommand.from(request);OrderDTOresultcreateOrderUseCase.execute(command);returnResponseEntity.status(HttpStatus.CREATED).body(result);}GetMapping(/{id})publicResponseEntityOrderDTOgetOrder(PathVariableLongid){OrderDTOresultgetOrderUseCase.execute(id);returnResponseEntity.ok(result);}}// JPA仓储出站适配器RepositorypublicclassJpaOrderRepositoryimplementsOrderRepository{AutowiredprivateOrderJpaRepositoryjpaRepository;OverridepublicOptionalOrderfindById(OrderIdid){returnjpaRepository.findById(id.getValue()).map(entity-/* 转换为领域对象 */);}OverridepublicOrdersave(Orderorder){OrderEntityentitytoEntity(order);jpaRepository.save(entity);returnorder;}}四、架构对比1. 六边形 vs 整洁架构维度六边形架构整洁架构核心理念端口与适配器依赖规则层次划分端口/适配器/应用/领域实体/用例/接口适配器/框架适用场景轻量级应用复杂企业应用学习曲线较平缓较陡峭灵活性高非常高2. 分层架构对比维度传统三层六边形整洁架构可测试性差好非常好可维护性一般好非常好耦合度高低最低复杂度低中高五、实战选择1. 何时使用六边形适合场景 - 微服务内部设计 - 需要与多个外部系统交互 - 希望保持业务逻辑的纯粹性 - 团队对DDD有一定了解2. 何时使用整洁架构适合场景 - 复杂的企业级应用 - 对可测试性要求极高 - 需要长期维护的项目 - 团队有较强的架构能力3. 实际项目建议// 项目结构建议根据复杂度选择// 简单项目六边形架构com.example ├── domain │ ├── model │ └── port # 端口定义 ├── application # 用例 └── adapter # 适配器// 复杂项目整洁架构com.example ├── domain │ ├── model │ ├── service │ └── port ├── application │ ├── usecase │ └── dto └── adapter ├── inbound └── outbound六、测试策略1. 领域层测试// 领域实体测试无需Spring纯单元测试classOrderTest{TestvoidshouldAddItemToDraftOrder(){// GivenOrderorderOrder.create(OrderId.of(123),CustomerId.of(456));// Whenorder.addItem(Product.of(P1,Money.of(100)),2);// ThenassertEquals(1,order.getItems().size());assertEquals(Money.of(200),order.getTotalAmount());}TestvoidshouldRejectAddItemToSubmittedOrder(){// GivenOrderorderOrder.create(OrderId.of(123),CustomerId.of(456));order.submit();// When/ThenassertThrows(BusinessException.class,()-order.addItem(Product.of(P1,Money.of(100)),2));}}2. 用例层测试// 用例测试使用MockExtendWith(MockitoExtension.class)classCreateOrderUseCaseTest{MockprivateOrderRepositoryorderRepository;MockprivateProductRepositoryproductRepository;MockprivateIdGeneratoridGenerator;InjectMocksprivateCreateOrderUseCaseImpluseCase;TestvoidshouldCreateOrderSuccessfully(){// GivenCreateOrderCommandcommandCreateOrderCommand.builder().customerId(C123).items(List.of(newOrderItemCommand(P1,2))).build();when(productRepository.findById(any())).thenReturn(Optional.of(Product.of(P1,Money.of(100))));when(idGenerator.generateId()).thenReturn(OrderId.of(O123));// WhenOrderDTOresultuseCase.execute(command);// ThenassertNotNull(result);verify(orderRepository).save(any());}}七、总结架构设计的选择建议六边形架构适合微服务、对接多外部系统整洁架构适合复杂业务、需要高可测试性核心原则业务逻辑与外部依赖解耦实施建议从六边形架构开始随着业务复杂度增加演进到整洁架构重视领域模型的设计保持架构的持续演进个人观点仅供参考