基于 DDD、EventSourcing 的现代响应式 CQRS 架构微服务开发框架

领域驱动  |  事件驱动  |  测试驱动  |  声明式设计 ｜ 响应式编程 ｜ 命令查询职责分离 ｜ 事件溯源

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• 特性(Snapshot): 快照策略支持 VersionOffsetSnapshotStrategy
• 特性(OpenAPI): 增强异常响应定义
• 特性(RouteSpec): 支持 LoadEventStreamRouteSpec
• 特性(CommandSpec): 增强空字符串命令请求头Command-*解析为未定义
• 依赖: 更新 io.opentelemetry:opentelemetry-bom 版本 v1.13.0

架构图

事件源

可观测性

Spring WebFlux 集成

自动注册 命令 路由处理函数 (HandlerFunction) ，开发人员仅需编写领域模型，即可完成服务开发。

测试套件：80%+ 的测试覆盖率轻而易举

Given -> When -> Expect .

前置条件

• 理解 领域驱动设计：《实现领域驱动设计》、《领域驱动设计：软件核心复杂性应对之道》
• 理解 命令查询职责分离（CQRS）
• 理解 事件溯源架构
• 理解 响应式编程

特性

•  Aggregate Modeling
  •  Single Class
  •  Inheritance Pattern
  •  Aggregation Pattern
•  Saga Modeling
  •  StatelessSaga
•  Test Suite
  •  兼容性测试规范（TCK）
  •  AggregateVerifier
  •  SagaVerifier
•  EventSourcing
  • EventStore
    •  MongoDB (Recommend)
    •  R2dbc
      •  Database Sharding
      •  Table Sharding
    •  Redis
  • Snapshot
    •  MongoDB
    •  R2dbc
      •  Database Sharding
      •  Table Sharding
    •  ElasticSearch
    •  Redis (Recommend)
•  命令等待策略（WaitStrategy）
  •  SENT : 命令发送成功后发送完成信号
  •  PROCESSED : 命令处理完成后发送完成信号
  •  SNAPSHOT : 快照生成完成后发送完成信号
  •  PROJECTED : 命令产生的事件被投影后发送完成信号
•  CommandBus
  •  InMemoryCommandBus
  •  KafkaCommandBus (Recommend)
  •  RedisCommandBus
  •  LocalFirstCommandBus
•  DomainEventBus
  •  InMemoryDomainEventBus
  •  KafkaDomainEventBus (Recommend)
  •  RedisDomainEventBus
  •  LocalFirstDomainEventBus
•  StateEventBus
  •  InMemoryStateEventBus
  •  KafkaStateEventBus (Recommend)
  •  RedisStateEventBus
  •  LocalFirstStateEventBus
•  Spring 集成
  •  Spring Boot Auto Configuration
  •  Automatically register CommandAggregate to RouterFunction
•  可观测性
  •  OpenTelemetry
•  OpenAPI
•  WowMetadata Generator
  •  wow-compiler

Example

Example

单元测试套件

80%+ 的测试覆盖率轻而易举。

Given -> When -> Expect .

Aggregate Unit Test (AggregateVerifier)

Aggregate Test

internal class OrderTest {

    private fun mockCreateOrder(): VerifiedStage<OrderState> {
        val tenantId = GlobalIdGenerator.generateAsString()
        val customerId = GlobalIdGenerator.generateAsString()

        val orderItem = OrderItem(
            GlobalIdGenerator.generateAsString(),
            GlobalIdGenerator.generateAsString(),
            BigDecimal.valueOf(10),
            10,
        )
        val orderItems = listOf(orderItem)
        val inventoryService = object : InventoryService {
            override fun getInventory(productId: String): Mono<Int> {
                return orderItems.filter { it.productId == productId }.map { it.quantity }.first().toMono()
            }
        }
        val pricingService = object : PricingService {
            override fun getProductPrice(productId: String): Mono<BigDecimal> {
                return orderItems.filter { it.productId == productId }.map { it.price }.first().toMono()
            }
        }
        return aggregateVerifier<Order, OrderState>(tenantId = tenantId)
            .inject(DefaultCreateOrderSpec(inventoryService, pricingService))
            .given()
            .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))
            .expectEventCount(1)
            .expectEventType(OrderCreated::class.java)
            .expectStateAggregate {
                assertThat(it.aggregateId.tenantId, equalTo(tenantId))
            }
            .expectState {
                assertThat(it.id, notNullValue())
                assertThat(it.customerId, equalTo(customerId))
                assertThat(it.address, equalTo(SHIPPING_ADDRESS))
                assertThat(it.items, equalTo(orderItems))
                assertThat(it.status, equalTo(OrderStatus.CREATED))
            }
            .verify()
    }

    /**
     * 创建订单
     */
    @Test
    fun createOrder() {
        mockCreateOrder()
    }

    @Test
    fun createOrderGivenEmptyItems() {
        val customerId = GlobalIdGenerator.generateAsString()
        aggregateVerifier<Order, OrderState>()
            .inject(mockk<CreateOrderSpec>(), "createOrderSpec")
            .given()
            .`when`(CreateOrder(customerId, listOf(), SHIPPING_ADDRESS, false))
            .expectErrorType(IllegalArgumentException::class.java)
            .expectStateAggregate {
                /*
                 * 该聚合对象处于未初始化状态，即该聚合未创建成功.
                 */
                assertThat(it.initialized, equalTo(false))
            }.verify()
    }

    /**
     * 创建订单-库存不足
     */
    @Test
    fun createOrderWhenInventoryShortage() {
        val customerId = GlobalIdGenerator.generateAsString()
        val orderItem = OrderItem(
            GlobalIdGenerator.generateAsString(),
            GlobalIdGenerator.generateAsString(),
            BigDecimal.valueOf(10),
            10,
        )
        val orderItems = listOf(orderItem)
        val inventoryService = object : InventoryService {
            override fun getInventory(productId: String): Mono<Int> {
                return orderItems.filter { it.productId == productId }
                    /*
                     * 模拟库存不足
                     */
                    .map { it.quantity - 1 }.first().toMono()
            }
        }
        val pricingService = object : PricingService {
            override fun getProductPrice(productId: String): Mono<BigDecimal> {
                return orderItems.filter { it.productId == productId }.map { it.price }.first().toMono()
            }
        }

        aggregateVerifier<Order, OrderState>()
            .inject(DefaultCreateOrderSpec(inventoryService, pricingService))
            .given()
            .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))
            /*
             * 期望：库存不足异常.
             */
            .expectErrorType(InventoryShortageException::class.java)
            .expectStateAggregate {
                /*
                 * 该聚合对象处于未初始化状态，即该聚合未创建成功.
                 */
                assertThat(it.initialized, equalTo(false))
            }.verify()
    }

    /**
     * 创建订单-下单价格与当前价格不一致
     */
    @Test
    fun createOrderWhenPriceInconsistency() {
        val customerId = GlobalIdGenerator.generateAsString()
        val orderItem = OrderItem(
            GlobalIdGenerator.generateAsString(),
            GlobalIdGenerator.generateAsString(),
            BigDecimal.valueOf(10),
            10,
        )
        val orderItems = listOf(orderItem)
        val inventoryService = object : InventoryService {
            override fun getInventory(productId: String): Mono<Int> {
                return orderItems.filter { it.productId == productId }.map { it.quantity }.first().toMono()
            }
        }
        val pricingService = object : PricingService {
            override fun getProductPrice(productId: String): Mono<BigDecimal> {
                return orderItems.filter { it.productId == productId }
                    /*
                     * 模拟下单价格、商品定价不一致
                     */
                    .map { it.price.plus(BigDecimal.valueOf(1)) }.first().toMono()
            }
        }
        aggregateVerifier<Order, OrderState>()
            .inject(DefaultCreateOrderSpec(inventoryService, pricingService))
            .given()
            .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))
            /*
             * 期望：价格不一致异常.
             */
            .expectErrorType(PriceInconsistencyException::class.java).verify()
    }
}

Saga Unit Test (SagaVerifier)

Saga Test

class CartSagaTest {

    @Test
    fun onOrderCreated() {
        val orderItem = OrderItem(
            GlobalIdGenerator.generateAsString(),
            GlobalIdGenerator.generateAsString(),
            BigDecimal.valueOf(10),
            10,
        )
        sagaVerifier<CartSaga>()
            .`when`(
                mockk<OrderCreated> {
                    every {
                        customerId
                    } returns "customerId"
                    every {
                        items
                    } returns listOf(orderItem)
                    every {
                        fromCart
                    } returns true
                },
            )
            .expectCommandBody<RemoveCartItem> {
                assertThat(it.id, equalTo("customerId"))
                assertThat(it.productIds, hasSize(1))
                assertThat(it.productIds.first(), equalTo(orderItem.productId))
            }
            .verify()
    }
}

设计

聚合建模

Single Class	Inheritance Pattern	Aggregation Pattern

加载聚合

聚合状态流

发送命令

命令与事件流

Saga - OrderProcessManager (Demo)