Quartz.NET开源作业调度框架系列(五):AdoJobStore保存job到数据库

　　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: