Quartz.NET开源作业调度框架系列(三):IJobExecutionContext 参数传递

　　前面写了关于Quartz.NET开源作业调度框架的入门和Cron Trigger , 这次继续这个系列, 这次想讨论一下Quartz.NET中的Job如何通过执行上下文(Execution Contex)进行参数传递 , 有些参数想保存状态该如何处理 . 在Quartz.NET中可以用JobDataMap进行参数传递.本例用Quartz.NET的任务来定期轮询数据库表,当数据库的条目达到一定的数目后,进行预警.(其实可以将读取的表和预警条件配置到数据库中的预警条件表中,这样就可以简单实现一个自动预警提醒的小平台).

1 JobWithParametersExample

 using System;
 using System.Threading;

 using Common.Logging;
 using Quartz;
 using Quartz.Impl;
 using Quartz.Job;
 using Quartz.Impl.Calendar;
 using Quartz.Impl.Matchers;
 namespace QuartzDemo
 {

     public class JobWithParametersExample
     {
         public string Name
         {
             get { return GetType().Name; }
         }
         private IScheduler sched = null;
         public JobWithParametersExample(IScheduler _sched)
         {
             sched = _sched;
         }
         public virtual void Run()
         {

             //2S后执行
             DateTimeOffset startTime = DateBuilder.NextGivenSecondDate(null, );
             IJobDetail job1 = JobBuilder.Create<JobWithParameters>()
                 .WithIdentity("job1", "group1")
                 .Build();

             ISimpleTrigger trigger1 = (ISimpleTrigger)TriggerBuilder.Create()
                                                            .WithIdentity("trigger1", "group1")
                                                            .StartAt(startTime)
                                                            .WithSimpleSchedule(x => x.WithIntervalInSeconds().WithRepeatCount())
                                                            .Build();

             // 设置初始参数
             job1.JobDataMap.Put(JobWithParameters.tSQL, "SELECT * FROM [ACT_ID_USER]");
             job1.JobDataMap.Put(JobWithParameters.ExecutionCount, );

             // 设置监听器
             JobListener listener = new JobListener();
             IMatcher<JobKey> matcher = KeyMatcher<JobKey>.KeyEquals(job1.Key);
             sched.ListenerManager.AddJobListener(listener, matcher);

             // 绑定trigger和job
             sched.ScheduleJob(job1, trigger1);
             //启动
             sched.Start();

         }
     }
 }

　　JobWithParametersExample用来配置job和trigger,同时定义了一个监听器,来监听定义的job.

2 JobWithParameters

 using System;
 using Common.Logging;
 using Quartz;
 using Quartz.Impl;
 using Quartz.Job;
 using System.Windows.Forms;
 namespace QuartzDemo
 {

     [PersistJobDataAfterExecution]
     [DisallowConcurrentExecution]
     public class JobWithParameters : IJob
     {

         // 定义参数常量
         public const string tSQL = "tSQL";
         public const string ExecutionCount = "count";
         public const string RowCount = "rowCount";
         public const string tableAlert = "tAlert";
         //  Quartz 每次执行时都会重新实例化一个类, 因此Job类中的非静态变量不能存储状态信息
          private int counter = ;//都为1
         //private static  int counter = 1;//可以保存状态
         public virtual void Execute(IJobExecutionContext context)
         {

             JobKey jobKey = context.JobDetail.Key;
             // 获取传递过来的参数
             JobDataMap data = context.JobDetail.JobDataMap;
             string SQL = data.GetString(tSQL);
             int count = data.GetInt(ExecutionCount);

             if (isOpen("FrmConsole"))
             {
                 try
                 {
                     //获取当前Form1实例
                     __instance = (FrmConsole)Application.OpenForms["FrmConsole"];
                     //获取当前执行的线程ID
                     __instance.SetInfo(jobKey + "Thread ID " + System.Threading.Thread.CurrentThread.ManagedThreadId.ToString());
                     //数据库操作
                     System.Data.DataTable tAlert = SqlHelper.getDateTable(SQL, null);
                     //回写条数
                     data.Put(RowCount, tAlert.Rows.Count);
                     //通过方法更新消息
                     __instance.SetInfo(string.Format("{0} exec {1} = {2} get {3} rows\r\n           execution count (from job map) is {4}\r\n           execution count (from job member variable) is {5}",
                     jobKey,
                     tSQL,
                     SQL,
                     tAlert.Rows.Count,
                     count, counter));
                     //怎么取出Datatable ? json to datatable
                     //data.Put(tableAlert, tAlert);
                 }
                 catch (Exception ex)
                 {
                     Console.WriteLine(ex.Message);
                 }
             }
             // 修改执行计数并回写到job data map中
             count++;
             data.Put(ExecutionCount, count);
             // 修改本地变量,如果是非静态变量,不能存储状态
             counter++;
         }

         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;
         }

     }
 }

Quartz 每次执行时都会重新实例化一个类, 因此Job类中的非静态变量不能存储状态信息.如何要保存状态信息可以用静态变量进行处理,也可以用参数值进行传入传出来实现.

3 JobListener

 using System;
 using Common.Logging;
 using Quartz;
 using Quartz.Impl;
 using Quartz.Job;
 namespace QuartzDemo
 {
     public class JobListener : IJobListener
     {

         public virtual string Name
         {
             get { return "JobListener"; }
         }

         public virtual void JobToBeExecuted(IJobExecutionContext inContext)
         {
             //执行前执行
             Console.WriteLine("JobToBeExecuted");
         }

         public virtual void JobExecutionVetoed(IJobExecutionContext inContext)
         {
             //否决时执行
             Console.WriteLine("JobExecutionVetoed");
         }

         public virtual void JobWasExecuted(IJobExecutionContext inContext, JobExecutionException inException)
         {
             JobKey jobKey = inContext.JobDetail.Key;
             // 获取传递过来的参数
             JobDataMap data = inContext.JobDetail.JobDataMap;
             //获取回传的数据库表条目数
             int rowCount = data.GetInt(JobWithParameters.RowCount);

             try
             {
                 if (rowCount > )
                 {
                     inContext.Scheduler.PauseAll();
                     System.Windows.Forms.MessageBox.Show("预警已超9条");
                     inContext.Scheduler.ResumeAll();

                 }
                 Console.WriteLine(rowCount.ToString());
             }
             catch (SchedulerException e)
             {

                 Console.Error.WriteLine(e.StackTrace);
             }
         }

     }
 }

4 效果