微服務實戰(七)：落地微服務架構到直銷系統(實現命令與命令處理器)

時間 2019-11-18

標籤微服務實落地架構直銷系統實現命令處理器欄目系統架構简体版

原文原文鏈接

咱們先來看看CQRS架構，你對下圖的架構還有印象嗎？每一個組件的功能都還清楚嗎？若是有疑問，請查考文章《微服務實戰(五)：落地微服務架構到直銷系統(構建高性能大併發系統)》。html

前一篇文章已經實現了Event Store的基礎功能部分，本篇文章咱們經過C端的標準方式，實現一個下單的高併發命令端，來看看須要實現的具體流程：前端

1.前端用戶調用一個下單Command WebApi，傳遞下單命令；下單Command WebApi接受到下單命令後，將下單命令數據投遞到一個命令隊列中，向前端用戶返回一個信息。web

2.下單Command Handler WebApi偵聽命令隊列中的下單命令，而後調用領域對象邏輯，將執行的結果也就是Order對象的當前狀態持久化到Event Store中。json

3.下單Command Handler WebApi將下單相關信息經過事件的方式發佈到一個事件隊列中。(用戶事件處理器最終將訂單信息更新到業務庫中)api

下面經過代碼簡單體現下過程：微信

1.定義建立訂單命令：架構

 public class CreateOrderCommand:BaseEvent
    {
        public OrderDTO orderdto { get; set; }
        public CreateOrderCommand() { }
        public CreateOrderCommand(OrderDTO orderdto)
        {
            this.orderdto = orderdto;
            this.AggregationRootId = Guid.NewGuid();
            this.AssemblyQualifiedAggreateRooType = typeof(Orders).AssemblyQualifiedName;
            this.AssemblyQualifiedCommandAndEventType = this.GetType().AssemblyQualifiedName;
        }
    }

2.訂單 Command WebApi接受前端用戶傳遞的訂單命令：併發

[Produces("application/json")]
    [Route("api/Order")]
    public class OrderController : Controller
    {
        private readonly IEventBus commandbus;
        public OrderController(IEventBus commandbus)
        {
            this.commandbus = commandbus;
        }
        [HttpPost]
        [Route("CreateOrderCmd")]
        public ResultEntity<bool> CreateOrderCmd([FromBody] OrderDTO orderdto)
        {
            var result = new ResultEntity<bool>();
            try
            {
                var createordercommand = new CreateOrderCommand(orderdto);
                //發佈命令到命令總線
                commandbus.Publish(createordercommand);
                result.IsSuccess = true;
                result.Msg = "下單處理中!";
            }
            catch(Exception error)
            {
                result.ErrorCode = 200;
                result.Msg = error.Message;
            }
            return result;
        }
    }

固然須要定義要注入的命令總線：app

public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
            //定義要發佈命令的命令總線
            services.AddSingleton<IEventHandlerExecutionContext>(new EventHandlerExecutionContext(services));
            var connectionFactory = new ConnectionFactory { HostName = "localhost" };
            services.AddSingleton<IEventBus>(sp => new RabbitMqEB(connectionFactory,
                sp.GetRequiredService<IEventHandlerExecutionContext>(), "exchange1", "direct", "ordercreatecommandqueue", 1));
        }

3.訂單Command Handler Web Api偵聽訂單命令，並訂閱須要處理訂單的訂單命令處理器：ide

            //偵聽訂單建立命令隊列裏的消息
            services.AddSingleton<IEventHandlerExecutionContext>(new EventHandlerExecutionContext(services));
            var connectionFactory = new ConnectionFactory { HostName = "localhost" };
            services.AddSingleton<IEventBus>(sp => new RabbitMqEB(connectionFactory,
                sp.GetRequiredService<IEventHandlerExecutionContext>(), "exchange1", "direct", "ordercreatecommandqueue", 2));

            //訂閱建立訂單命令
            var commandbuss = app.ApplicationServices.GetServices<IEventBus>();
            var commandbus = commandbuss.ToList()[0];
            commandbus.Subscribe<CreateOrderCommand, OrderCreateCommandHandler>();

4.實現訂單命令處理器：

public class OrderCreateCommandHandler : IEventHandler
    {
        private readonly IServiceProvider iserviceprovider;
        public OrderCreateCommandHandler()
        {
            var iwebhost = FindIWebHost.GetWwebHost("OrderCommandHandler.WebApi");
            iserviceprovider = iwebhost.Services;

        }
        public Task<bool> HandleAsync<TEvent>(TEvent @event) where TEvent : IEvent
        {
            var orderdtocommand = @event as CreateOrderCommand;
            var orderdto = orderdtocommand.orderdto;
            var orderid = orderdtocommand.AggregationRootId;
            Orders order = new Orders();
            var productskus = new List<ProductSKU>();
            for (int i = 0; i < orderdto.ProductSPUNames.Count; i++)
            {
                var productsku = new ProductSKU();
                productsku.ProductSPUName = orderdto.ProductSPUNames[i];
                productsku.DealerPrice = orderdto.ProductDealerPrices[i];
                productsku.PV = orderdto.ProductPVS[i];
                productsku.Id = orderdto.ProductSKUIds[i];
                productsku.Spec = orderdto.ProductSepcs[i];
                productskus.Add(productsku);
            }
            var contact = new Contact();
            contact.ContactName = orderdto.ContactName;
            contact.ContactTel = orderdto.ContactTel;
            contact.Province = orderdto.Privence;
            contact.City = orderdto.City;
            contact.Zero = orderdto.Zero;
            contact.Street = orderdto.Street;
            //完成業務邏輯
            var orders = order.CreateOrders(orderid, orderdto.DealerId, productskus, orderdto.Counts,
                contact);

            var ordercreateevent = new OrderCreateEvent();
            ordercreateevent.AggregationRootId = orders.Id;
            ordercreateevent.AssemblyQualifiedAggreateRooType = orderdtocommand.AssemblyQualifiedAggreateRooType;
            ordercreateevent.AssemblyQualifiedCommandAndEventType = orderdtocommand.AssemblyQualifiedCommandAndEventType;
            ordercreateevent.CreateDate = orders.OrderDateTime;
            ordercreateevent.Id = orders.Id;
            ordercreateevent.OrderDateTime = orders.OrderDateTime;
            ordercreateevent.OrderDealerId = orders.OrderDealerId;
            ordercreateevent.OrderItems = orders.OrderItems;
            ordercreateevent.OrderStreet = orders.OrderStreet;
            ordercreateevent.OrderTotalPrice = orders.OrderTotalPrice;
            ordercreateevent.OrderTotalPV = orders.OrderTotalPV;
            ordercreateevent.Code = orders.Code;
            ordercreateevent.Telephone = orders.Telephone;
            ordercreateevent.Version = 0;
            //對建立訂單事件持久化事件存儲
            try
            {
                new DomainAndEventStorage().SaveEvent(ordercreateevent);
                var eventbuss = iserviceprovider.GetServices(typeof(IEventBus))
                    as IEnumerable<IEventBus>;
                var eventbusls = eventbuss.ToList();
                var eventbus = eventbusls[1];
                //發佈到事件隊列，用於將來持久化到業務庫中
                eventbus.Publish(ordercreateevent);
            }
            catch(Exception error)
            {
                throw error;
            }
            return Task.FromResult(true);
        }
    }