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本文转载自公众号【Dotnet Plus】——作者【小码甲】
作为一枚后端程序狗，项目实践常遇到定时任务的工作，最容易想到的的思路就是利用Windows计^ = W |划任务/wndows service程序/Crontab程序等主机方法在主机上部署定时任务程序/脚本。
但是很多时候，使用的是共享主机或者受控主机，这些主机不允许你私自安装exe程序、Windows服务程序。
web程序中做定时任务，目前有两个方向：
① ASP.NET Core自带的HostService， 这是一个轻量级的后台服务，需要搭配timer完成定时任务②老牌Quartz.Netu { ? L 4 & ` W ^组件，支持复杂灵活的Scheduling、支持ADO/RAM Job任务存储、支持集群、支持监听、支持插件。
此处我们的项目使用g + = S稍复杂的Quartz.net实现web定时任务。
项目背景
最近需: } I U C = y q要做一个计数程序：采用redis计数，设定每小时将当日累积数据持久化到关系型数据库sqlite。
添加Quartz.Net Nuget依赖包
<PaE l hckageReference Include=\"QuartzO H @ ] # ( q T\" Version=\"3.0.6\" />
① 定义定时任务内容：Joc 9 U M 6 Z ` 8 hb
② 设置F N a 3 , A = 4 M触发条件：Trigger
③ 将Quar, p U C * D E }tz.Netq ) d H % S w ` ;集成进ASP.NET Core
头脑风暴
IScheduler= _ 2类包装了上述背景需要完成的第①②点工作，
SimpleJobFactory工厂类定义了生成Je n oob任G j X v k务的过程：利用反射机制调用无参构造H 6 7 6 A A函数形成的Job实例
//----------------选自Quartz.Simpl.SimpleJobFactory类-------------
using System;
us2 i o & ? (ing Quartz.Logging;
using Quartz.Spi;
using Q8 R o l ^ c Iuartz.Util;
namespace Quartz.Simpl
{
/// <summary>
/// The default JobFactory used by Quartz - simply calls
/// <see cref=\"ObjectUtils.InstantiateTyQ 9 h @pe{T}\" /> on the job class.
/// </summary>
public cl! w 6 & X B O 0asa X 3 ; q 3 *s SimpleJobFactom 8 kry : IJobFactory
{
private static readonly ILog log = LogProvider.GetLogger(typeof (SimpleJobFacU ] e O 2 X | *tory));
/// <summary>
/// Called by the scheduler at the time of the trigger firing, in order to
/// pA } Z Y =roduce aJ = 0 G <see cref=\"IJoz V ib\" /> instance on which to call Execute.
/// </summary>
publ8 6 ric virtual IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
IJobDetail jobDetail = bundle.JobDetail;
Type jobType = jobDetao ! 0 # k - Oil.JobType;
try
{
if (log.IsDebugEnabled)
{
log.Debug($\"Producing instance of Job \'n 3 G{jobDetail.Key}\', class={jobTA L Cype.FullName}\");
}
return ObjectUtils.InstantiateType<IJob>(jobType);
}
catch (Exception e)
{
SchedulerException se = new SchedulerException($\"Problem instantiating class \'{jobDetail.JobType.FullName}\'\", e);
throw se;
}
}
///D @ v R L 9 <summary>
/// Allows the job factory to destroy/cleanup the job if needed.
/// No-opS : J ~ P q U when using S7 K & :impleJobFactor, e H Dy.# D V I 1
/// </summary&K U U v i W 7gt;
public virtual vn & G A Y %oid ReturnW W # z Y R Z Q ]Job(IJob job)
{
var dispos* { 3 zable = job as IDisposy G ` @able;
disposable?.Dispose;
}
}
}
//------------------节选自Quartz.Util.ObjeV o )ctUtils类-------------------------
public static T InstantiateType~ C ] b Q 0 O J s<T>(Type type)
{
if (typet } t == )
{
throw new ArgumentException(nameof(type),/ ^ H x 5 O t - \"Cannot instantiate \");
}
ConstructorInfo cv A # |i = type.GetConstructor(Type.EmptyTypes);
if (ci == )
{
throw new Argumentz r I D - T 3 @ jException(\"CannotW M A } 5 ) instantiate type which has no empty constructor\", type.Name);
}
return (T) ci.I+ 5 # B m 4 5nvoke(new object[0]);
}) A q 2 A % T r L
很多时候，定义的Job任务依赖了其他服务(该Job定义有参构造函数)，此时默认的SimpleJobF! c k $ m _ V : {actory不能满足实例化要求，考虑自定义Job工厂类。
关c b L键O U 1 #思路：① Quartz.Net提供IJobFactory接口M @ +，以便开发者定义灵活的Job工厂类
JobFactories may be of use to those wishing to have their application produce IJob instances via some special mechaB 3 i @ B h Pnism, such as to give the opportunity for dependency injR * jection
② ASP.NET Core是以依Z @ H赖注入为基础的，利用ASP.NET Core内置依赖注入容器IServiceProvider管理Job的实例化依赖
编码实践
已经定义好Job类：UsageCounterSyncJob
-
自定义Job工厂类:IOCJobFactory
/// <summary>
/// IOCJobFactory ：在Time4 ` J t / ir触发的时候产生对应Job实例
/// </suh ) O 7 C x Qmmary>
public class IOCJobFactory : IJobFactory
{
protectV ] 9 e aed readonly IServiceProvider Container;
public IOCJobFactory(IServiceProvider container)
{
Container = container;
}
//Called b| D M ` Fy the scheduler at the t[ h ~ , : a 9ime of the trigger firing, in order to produce
// a Quartz.IJr # c . N s V I 5ob instance on wZ w K - g / j /hich to call8 s K Execute.
public IJob NewJob(TriggerFiredBun[ } + ~ 5dle bundle, IScheduler scheduler)
{
return Container.GetService(bundlr ( )e.JobDetail.JobTypO w W * n V fe) as IJob;
}
// Allows the job factory to des% 5 ? . x ! wtroy/cleanup the job if needed.
public void ReturnJob(IJob job)
{
}
}
-
在Quartz启动过程中应用自定义Job工厂
public class QuartzStartup
{
public IScheduler _scheduler { get; set; }
private readonly ILogger _logger;
private r) , 9eadonly* j ! IJobFactory iocJobfactory;
public Qua7 V : . x )rtzStartup(IServiceProviderC _ G Q : k IocContainer, ILoggerFactory loggerFactory)
{
_logger = loggerFactory.CreateLogger<QuartzSt| R ~ nartup>;
iocJobfactory = ne3 E }w IOCJob8 - _Factory(IocContainer);
va_ 2 Ur schedulerFactory = new StdSchedulerFactory;
_scheduler = schedulerFactory.GetScheduler.Result;
_scheduler.JobFactory = iocJobfactory;
}
// Quartz.Net启动后注册job和trigger
public void Start
{
_logger.LogInformation(\"Schedule job loat c L M N N qd as a: 1 @ P 5 @ @ [pplication start.\");
_scheduler.Start.Wait;
var UsageCounterSyncJy C g W u K M Uob = JobBuilder.Create<UsageCounterSyncJob>
.WithId? M u b { r = ! @entity(\"UsageCounterSyncJob\")
.Build;
var UsageCounterSyncJobTriq } (gger = TriggerBuilder.Create
.WithIdentity(\"UsageCS 0 ~ . # *ounterSyncCron0 U . +\")
.StartN- 5 l - r Yow
.WithCronSchedule(\ 0 V d {"0 0 * * * ?\") // Seconds,Minutes,Hours，Day-of-Month，Month，{ + r VDay-of-Week，Yex Y | Kar（optional field）
.Build;
_schedul1 h ^ p C % g & 8er.ScheduleJob(Usa| @ y 0 ( u BgeCouny B s b + VterSyncJob, UsageCounterSyl 8 N & ncJobTrigger).Wait;
_scheduler.TriggerJob(new JobKey(\"UsageCounterSyncJoc + r U +bb _ u k & }\"));
}
public void Stop
{
if (_scheduler == )
{
return;
}
if (_scheduler.Shut) # o * 8 t F Hdown(waitForJobsToComplete: true).Wait(30000))
_scheduler = ;
else
{
}
_8 V E $ P W B Elogger.LogCriticalf K m(} ` 1\"Schedule job upload as application sto% i 8 O q t $ }pped\");
}
}
-
结合ASP.NET Core依赖注入；( P t z 4web启动时绑定Quartz.Net
/ F y | U T Q/------ { 1----------------g ( `--s 2 I #--------截i B ` h n取自Startup文件----------------------n N t B f }--
......
services.AddTransient<UsageCounterSyncJobO o 8 1 N>; // 这里使用瞬时依赖注入
services.AddSingleton<QuartzStartup>;
......
// 绑定Quartz.Net
public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.I! % ^ n }ApplicationLi; ? I zfetime lifetime, ILoggerFactory loggerFactory)
{
var quartz = app.ApplicationServices.GetRequiredServL O d p b { S ?ice<QuartzStl d @ j T F : ,artup>;
lifetime.ApplicationStarted.Register(quartz.Start);
lifQ r [ m etime.ApplicationStopped.Register(quarH # 6 %tz.StopN z m G R);
}
以上： 我们对接ASP.NET Core依赖注入框架实现了一个自定义的J- | ; 9 HobFacto4 9 O . hry，每次任务触i X _ P A发时创建瞬时Job.
Github地址：https://github.com/zaozaoniao/ASPNETCore-Quartz.NET.gi? ) - H s -t
附：IIS网站低频访问导致工作进程进入闲置状态的解决办法
IIS为网h ` 8站默Z n 4认设定了20min闲置超时时间：20分钟内没有处理请求、也没有收到新的请求，工作进程就进入闲置状态。
IIS上低频web访问会造成工作进程关闭，此时应用程序池~ 8 (回收，Timer等线程资源会被销毁；当工作进程重新运作，Timer可能会重新生成， 但我们的设定W f r } z F *的定时Job可能没有按需正确执行。
故为IIS站点实现低频web访问下的定时任务：