一种异步作业处理请求任务的简单实现（以短信发送为例）

对于以下几类任务，可能需要异步处理，即不是在接口中处理任务，而是在另一个调用作业中处理：

1. 处理比较耗时、耗时CPU、内存资源
2. 不很稳定、可能失败但又比较重要，若失败需要多尝试几次
3. 请求量大、性能要求高。若放在接口中处理不方便拓展机器、负载等

主要程序流程图如下：

下面说下程序主要框架：

1.框架         

1.Interface 短信发送请求接口，通过json类对象调用。只接受保存任务，状态-未处理。稍后异步在job里处理
2.Job 异步的后端短信发送程序，一个个处理未发送的消息，含2个互备供应商，可切换
3.Web 后台，查看任务处理情况、账号等
4.Interface.Entity 接口模型实体，请求、响应类对象
5.Test 接口请求测试项目，通过Entity的json序列化、http post参数形式请求Interface
6.Model DB模型，含底层EF操作类库
7.Service 主要业务逻辑封装
8.Repository 主要DB对象封装

2.接口

public class InterfaceController : Controller
    {
        public void Index()
        {
            Response.Write("欢迎访问消息发送接口");
        }

        [HttpPost]
        public JsonResult Send()
        {
            MessageResponseEntity response;
            try
            {
                string jsonRequest = GetPostData();
                if (jsonRequest.IsNullOrWhiteSpace())
                {
                    response = new MessageResponseEntity
                    {
                        TaskId = string.Empty,
                        SendStatus = SendStatus.SendFailure,
                        ResultDescription = "所有请求参数为空",
                    };
                }
                else
                {
                    MessageRequestEntity request = JsonConvert.DeserializeObject<MessageRequestEntity>(jsonRequest);
                    var service = new SendService();
                    response = service.Verify(request);
                    if (response.SendStatus != SendStatus.SendFailure)
                        response = service.SaveMessage(request);
                }
            }
            catch (Exception ex)
            {
                response = new MessageResponseEntity
                {
                    TaskId = string.Empty,
                    SendStatus = SendStatus.SendFailure,
                    ResultDescription = string.Format("服务器端出错，原因:{0},{1}",ex.Message,ex.StackTrace),
                };
            }
            return Json(response);
        }

        public string GetPostData()
        {
            string postData = string.Empty;
            if (Request.RequestType == "POST")
            {
                using (Stream sm = Request.InputStream)
                {
                    int len = (int)sm.Length;
                    byte[] inputByts = new byte[len];
                    sm.Read(inputByts, 0, len);
                    postData = Server.UrlDecode(Encoding.GetEncoding(Encoding.UTF8.WebName).GetString(inputByts));
                }
            }
            return postData;
        }
    }

3.调用方法：

            //调用测试
            var request = new MessageRequestEntity
            {
                Content = "测试",
                Receivers = "15951984463",
                AccountGuid = "a8bfdd46-e7f6-4ad6-9fc6-ce69a9eb2633",
            };
            var response = CommTools.WebUtils.Post<MessageResponseEntity>("http://localhost:1952/Interface/send", request);
            Response.Write(string.Join(",", response.TaskId, response.SendStatus, response.ResultDescription));      

4.处理作业

public class HomeController : Controller
    {
        public static JobStatus JobStatus; 

        public ActionResult Index()
        {
            ViewBag.Message = "欢迎访问发送信息Job!  当前Job运行状态:" + JobStatus.ToString();
            return View();
        }

        public void StartJob()
        {
            Response.Write("发送信息Job已启动");
            JobStatus = JobStatus.Running;
            var taskOperation = new TaskOperation();
            while (true)
            {
                taskOperation.SingleSendMessage();
                Thread.Sleep(100);  //暂停100毫秒，即100毫秒处理一个消息发送任务
            }
        }
    }

public void SingleSendMessage()
        {
            var taskRepos = new TaskRepository();
            Task waitSendTask = taskRepos.GetTopWaitSendTask();
            if (waitSendTask != null)
            {
                bool supplierResult;
                int supplierId;
                //指定模式：0-先提交供应商A,再提交B；1-只提交供应商A,对应A Id；2-只提交供应商B,对应B Id。
                int supplierMode = int.Parse(ConfigurationManager.AppSettings["SupplierMode"]);
                switch (supplierMode)
                {
                    case 0: 
                        {
                            supplierId = 1;
                            supplierResult = new SupplierA().SendMessage(waitSendTask);
                            if (!supplierResult)    //提交供应商A失败则提交供应商B
                            {
                                supplierId = 3;
                                supplierResult = new SupplierB().SendMessage(waitSendTask);
                            }
                            break;
                        }
                    case 1:
                        {
                            supplierId = 1;
                            supplierResult = new SupplierA().SendMessage(waitSendTask);
                            break;
                        }
                    case 3:
                        {
                            supplierId = 3;
                            supplierResult = new SupplierB().SendMessage(waitSendTask);
                            break;
                        }
                    default:
                        {
                            supplierId = 1;
                            supplierResult = new SupplierA().SendMessage(waitSendTask);
                            break;
                        }
                }

                if(supplierResult)
                    taskRepos.TaskSendStatus(waitSendTask.TaskId, SendStatus.SendSuccess, "发送成功",supplierId);
                else
                    taskRepos.TaskSendStatus(waitSendTask.TaskId, SendStatus.SendFailure, "发送失败：提交供应商失败", supplierId);
            }
        }

具体代码，我打包提交上来或者git上传，供各位参考