秒杀-订单创建消费者CreateOrderConsumer

这个类是基于MassTransit框架的消息消费者，负责接收 “库存扣减成功” 的消息并创建秒杀订单，同时通过消息通知库存服务确认订单状态。

using MassTransit;
using MassTransit.Transports;
using SqlSugar;
using System.Transactions;
using ZR.Common.Model;
using ZR.Model.Stock;
using ZR.Service.Stock.IStockService;/// <summary>
/// 订单创建消息消费者
/// 负责消费 CreateOrderMessage 消息，完成秒杀订单的创建
/// </summary>
public class CreateOrderConsumer : IConsumer<CreateOrderMessage>
{// 本地消息表服务（操作库存服务的消息记录）private readonly IStockMessageService _StockMessageService;// 秒杀订单服务（操作订单数据库）private readonly ISeckillOrderService _SeckillOrderService;// SqlSugar 数据库客户端（用于事务管理）private readonly ISqlSugarClient _SqlSugarClient;// MassTransit 消息总线（用于发送确认消息）private readonly IBus _bus;/// <summary>/// 构造函数注入依赖/// 通过依赖注入获取所需服务，解耦组件间依赖/// </summary>public CreateOrderConsumer(IStockMessageService stockMessageService, ISeckillOrderService seckillOrderService,ISqlSugarClient sqlSugarClient, IBus bus){_StockMessageService = stockMessageService;_SeckillOrderService = seckillOrderService;_SqlSugarClient = sqlSugarClient;_bus = bus;}/// <summary>/// 消费消息的核心方法/// 当 CreateOrderMessage 消息到达时自动调用/// </summary>public async Task Consume(ConsumeContext<CreateOrderMessage> context){Console.WriteLine("_____________________CreateOrderConsumer____________");var message = context.Message; // 获取消息内容（订单号、商品ID、用户ID等）// 1. 幂等性检查：判断订单是否已存在（防止消息重复消费导致重复创建订单）var exist = await _SeckillOrderService.GetFirstAsync(x => x.OrderNo == message.OrderNo);if (exist != null){// 订单已存在：直接发送“订单创建确认”消息，通知库存服务更新消息状态var uri = new Uri("exchange:stockConfirmQueue.direct?type=direct"); // 目标交换机地址var endPonit = await _bus.GetSendEndpoint(uri); // 获取消息发送端点if (endPonit == null)throw new Exception("消息创建失败");// 发送确认消息（包含订单号）await endPonit.Send(new ConfirmOrderCreatedMessage{OrderNo = message.OrderNo,}, ctx =>{ctx.SetRoutingKey("orderpublic"); // 指定路由键，匹配库存确认队列});return;}// 2. 订单不存在：创建新订单bool dbok = false; // 数据库事务是否成功string mess = "";  // 事务信息try{// 使用 SqlSugar 事务包装订单创建操作（确保原子性）(dbok, mess) = await _SqlSugarClient.UseTranAsync(async () =>{// 创建秒杀订单实体var order = new SeckillOrder{OrderNo = message.OrderNo,   // 订单号（与库存服务生成的一致）GoodsId = message.GoodsId,   // 商品IDUserId = message.UserId,     // 用户IDStatus = "0",                // 订单状态（0-待支付）CreateTime = DateTime.Now,   // 创建时间};// 保存订单到数据库_SeckillOrderService.Add(order);});// 3. 订单创建成功后，发送“订单创建确认”消息var uri = new Uri("exchange:stockConfirmQueue.direct?type=direct");var endPonit = await _bus.GetSendEndpoint(uri);if (endPonit == null)throw new Exception("消息创建失败");await endPonit.Send(new ConfirmOrderCreatedMessage{OrderNo = message.OrderNo,}, ctx =>{ctx.SetRoutingKey("orderpublic");});}catch (Exception ex){// 异常时直接返回（依赖 MassTransit 重试机制重新消费消息）return;}}
}