Quartz.NET 任务调度的核心元素是 scheduler, trigger 和 job，其中 trigger(用于定义调度时间的元素，即按照什么时间规则去执行任务) 和 job 是任务调度的元数据，scheduler 是实际执行调度的控制器。在Quartz.NET中主要有两种类型的 job：无状态的（stateless）和有状态的（stateful）。对于同一个 trigger 来说，有状态的 job 不能被并行执行，只有上一次触发的任务被执行完之后，才能触发下一次执行。无状态任务一般指可以并发的任务，即任务之间是独立的，不会互相干扰。一个 job 可以被多个 trigger 关联，但是一个 trigger 只能关联一个 job。某些任务需要对数据库中的数据进行增删改处理 , 这些任务不能并发执行，就需要用到无状态的任务 , 否则会造成数据混乱。
另外有些情况下,我们需要将任务保存到数据库中,特别是有些任务中包含参数,例如累加的任务,如果可以保存到数据库中,即便中间断电或者程序异常重启,中间计算的结果也不会丢失,可以从断点的结果进行运算(首先恢复任务),下面介绍一下如何用AdoJobStore将任务保存到SQL Server数据库中.
事先要在数据库上新建一个QRTZ_数据库,并执行SQL建表脚本:
1 RecoveryJob
是一个无状态的任务,代码如下:
using System;
using System.Collections.Specialized;
using System.Threading;
using Common.Logging;
using Quartz;
using Quartz.Impl;
using Quartz.Job;
using System.Windows.Forms;
namespace QuartzDemo
{
/// <summary>
/// 无状态的可恢复的任务
/// </summary>
public class RecoveryJob : IJob
{ private const string Count = "count";
public virtual void Execute(IJobExecutionContext context)
{ JobKey jobKey = context.JobDetail.Key;
if (isOpen("FrmConsole"))
{
try
{
//获取当前Form1实例
__instance = (FrmConsole)Application.OpenForms["FrmConsole"];
// 如果任务是恢复的任务的话
if (context.Recovering)
{
__instance.SetInfo(string.Format("{0} RECOVERING at {1}", jobKey, DateTime.Now.ToString("r")));
}
else
{
__instance.SetInfo(string.Format("{0} starting at {1}", jobKey, DateTime.Now.ToString("r")));
} JobDataMap data = context.JobDetail.JobDataMap;
int count;
if (data.ContainsKey(Count))
{
//是否能从数据库中恢复,如果保存Job等信息的话,程序运行突然终端(可用调试时中断运行,而不是关闭窗体来模拟)
count = data.GetInt(Count);
}
else
{
count = ;
}
count++;
data.Put(Count, count); __instance.SetInfo(string.Format(" {0} Count #{1}", jobKey, count));
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
} private static FrmConsole __instance = null; /// <summary>
/// 判断窗体是否打开
/// </summary>
/// <param name="appName"></param>
/// <returns></returns>
private bool isOpen(string appName)
{
FormCollection collection = Application.OpenForms;
foreach (Form form in collection)
{
if (form.Name == appName)
{
return true;
}
}
return false;
} }
}
2 RecoveryStatefulJob
是一个有状态的任务,和无状态的区别就是在任务类的上面用[PersistJobDataAfterExecution]标注任务是有状态的 , 有状态的任务不允许并发执行,也需要标注 [DisallowConcurrentExecution],代码如下:
using System;
using System.Collections.Specialized;
using System.Threading;
using Common.Logging;
using Quartz;
using Quartz.Impl;
using Quartz.Job;
using System.Windows.Forms;
namespace QuartzDemo
{
/// <summary>
/// 用这个[PersistJobDataAfterExecution]标注任务是有状态的,
/// 有状态的任务不允许并发执行 [DisallowConcurrentExecution]
/// </summary>
[PersistJobDataAfterExecution]
[DisallowConcurrentExecution]
public class RecoveryStatefulJob : RecoveryJob
{ }
}
3 AdoJobStoreExample
用 properties["quartz.dataSource.default.connectionString"] = "Server=(local);Database=QRTZ_;Trusted_Connection=True;";定义了数据库的连接信息,程序运行时会自动将任务保存到数据库中:
using System;
using System.Collections.Specialized;
using System.Threading;
using Common.Logging;
using Quartz;
using Quartz.Impl;
using Quartz.Job;
using System.Windows.Forms;
namespace QuartzDemo
{
/// <summary>
/// AdoJobStore的用法示例
/// </summary>
public class AdoJobStoreExample
{
public virtual void Run(bool inClearJobs, bool inScheduleJobs)
{
NameValueCollection properties = new NameValueCollection(); properties["quartz.scheduler.instanceName"] = "TestScheduler";
properties["quartz.scheduler.instanceId"] = "instance_one";
properties["quartz.threadPool.type"] = "Quartz.Simpl.SimpleThreadPool, Quartz";
properties["quartz.threadPool.threadCount"] = "";
properties["quartz.threadPool.threadPriority"] = "Normal";
properties["quartz.jobStore.misfireThreshold"] = "";
properties["quartz.jobStore.type"] = "Quartz.Impl.AdoJobStore.JobStoreTX, Quartz";
properties["quartz.jobStore.useProperties"] = "false";
properties["quartz.jobStore.dataSource"] = "default";
properties["quartz.jobStore.tablePrefix"] = "QRTZ_";
properties["quartz.jobStore.clustered"] = "true";
// SQLite
// properties["quartz.jobStore.lockHandler.type"] = "Quartz.Impl.AdoJobStore.UpdateLockRowSemaphore, Quartz";
properties["quartz.jobStore.driverDelegateType"] = "Quartz.Impl.AdoJobStore.SqlServerDelegate, Quartz";
// 数据库连接字符串
properties["quartz.dataSource.default.connectionString"] = "Server=(local);Database=QRTZ_;Trusted_Connection=True;";
properties["quartz.dataSource.default.provider"] = "SqlServer-20"; // First we must get a reference to a scheduler
ISchedulerFactory sf = new StdSchedulerFactory(properties);
IScheduler sched = sf.GetScheduler(); bool b是否恢复 = false;
if (inClearJobs)
{
Console.WriteLine("***** Deleting existing jobs/triggers *****");
// sched.Clear();
} if (inScheduleJobs)
{ string schedId = sched.SchedulerInstanceId; int count = ; //定义一个无状态的任务
IJobDetail job = JobBuilder.Create<RecoveryJob>()
.WithIdentity("recoveryjob_" + count, schedId)
.RequestRecovery() //recovery
.Build(); ISimpleTrigger trigger = (ISimpleTrigger)TriggerBuilder.Create()
.WithIdentity("triger_" + count, schedId)
.StartAt(DateBuilder.FutureDate(, IntervalUnit.Second))
.WithSimpleSchedule(x => x.WithRepeatCount().WithInterval(TimeSpan.FromSeconds()))
.Build();
//可用此来查看定义的触发器触发规则
//log.InfoFormat("{0} will run at: {1} and repeat: {2} times, every {3} seconds",
//job.Key, trigger.GetNextFireTimeUtc(),
//trigger.RepeatCount,
//trigger.RepeatInterval.TotalSeconds);
try
{
//如果数据库已经存在同名job和trigger,则绑定失败
sched.ScheduleJob(job, trigger);
}
catch
{
b是否恢复 = true;
}
count++; //定义一个有状态的任务***********************************************************
job = JobBuilder.Create<RecoveryStatefulJob>()
.WithIdentity("Statefuljob_" + count, schedId)
.RequestRecovery() // recovery
.Build(); trigger = (ISimpleTrigger)TriggerBuilder.Create()
.WithIdentity("triger_" + count, schedId)
.StartAt(DateBuilder.FutureDate(, IntervalUnit.Second))
.WithSimpleSchedule(x => x.WithRepeatCount().WithInterval(TimeSpan.FromSeconds()))
.Build(); try
{
sched.ScheduleJob(job, trigger);
}
catch
{
b是否恢复 = true;
} } //启动
sched.Start();
//sched.Shutdown(); } public string Name
{
get { return GetType().Name; }
} public void Run()
{
bool clearJobs = true;
//clearJobs = false;
bool scheduleJobs = true;
AdoJobStoreExample example = new AdoJobStoreExample();
example.Run(clearJobs, scheduleJobs);
}
}
}
可以看到有状态的计数每次累加1,而无状态的每次执行时都会丢失累加数(新的实例),中断程序,查看数据库的QRTZ_JOB_DETAILS表,可以看见还有一个持久化的任务:
中断程序后(调试状态时不关闭窗体,而是中断调试,模拟异常关闭) ,再重新运行可以看到如下界面: