Quartz.net官方开发指南 第七课 : TriggerListeners和JobListeners

监听器是在scheduler事件发生时能够执行动作的对象。可以看出，TriggerListeners接收与triggers相关的事件，而JobListeners则接收与Job相关的事件。

Trigger相关的事件包括：trigger触发、trigger未触发，以及trigger完成（由trigger触发的任务被完成）。

/// <summary>

/// The interface to be implemented by classes that want to be informed when a

/// <see cref="Trigger" /> fires. In general, applications that use a

/// <see cref="IScheduler" /> will not have use for this mechanism.

/// </summary>

/// <seealso cref="IScheduler" />

/// <seealso cref="Trigger" />

/// <seealso cref="IJobListener" />

/// <seealso cref="JobExecutionContext" />

/// <author>James House</author>

public interface ITriggerListener

{

/// <summary>

/// Get the name of the <see cref="ITriggerListener" />.

/// </summary>

string Name { get; }

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />

/// has fired, and it's associated <see cref="JobDetail" />

/// is about to be executed.

/// <p>

/// It is called before the <see cref="VetoJobExecution" /> method of this

/// interface.

/// </p>

/// </summary>

/// <param name="trigger">The <see cref="Trigger" /> that has fired.</param>

/// <param name="context">

/// The <see cref="JobExecutionContext" /> that will be passed to the <see cref="IJob" />'s<see cref="IJob.Execute" /> method.

/// </param>

void TriggerFired(Trigger trigger, JobExecutionContext context);

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />

/// has fired, and it's associated <see cref="JobDetail" />

/// is about to be executed.

/// <p>

/// It is called after the <see cref="TriggerFired" /> method of this

/// interface.

/// </p>

/// </summary>

/// <param name="trigger">The <see cref="Trigger" /> that has fired.</param>

/// <param name="context">

/// The <see cref="JobExecutionContext" /> that will be passed to

/// the <see cref="IJob" />'s<see cref="IJob.Execute" /> method.

/// </param>

bool VetoJobExecution(Trigger trigger, JobExecutionContext context);

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />

/// has misfired.

/// <p>

/// Consideration should be given to how much time is spent in this method,

/// as it will affect all triggers that are misfiring. If you have lots

/// of triggers misfiring at once, it could be an issue it this method

/// does a lot.

/// </p>

/// </summary>

/// <param name="trigger">The <see cref="Trigger" /> that has misfired.</param>

void TriggerMisfired(Trigger trigger);

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="Trigger" />

/// has fired, it's associated <see cref="JobDetail" />

/// has been executed, and it's <see cref="Trigger.Triggered" /> method has been

/// called.

/// </summary>

/// <param name="trigger">The <see cref="Trigger" /> that was fired.</param>

/// <param name="context">

/// The <see cref="JobExecutionContext" /> that was passed to the

/// <see cref="IJob" />'s<see cref="IJob.Execute" /> method.

/// </param>

/// <param name="triggerInstructionCode">

/// The result of the call on the <see cref="Trigger" />'s<see cref="Trigger.Triggered" /> method.

/// </param>

void TriggerComplete(Trigger trigger, JobExecutionContext context, SchedulerInstruction triggerInstructionCode);

}

与任务相关的事件包括：即将被执行的任务的通知和任务已经执行完毕的通知。

The.JobListener Interface

/// <summary>

/// The interface to be implemented by classes that want to be informed when a

/// <see cref="JobDetail" /> executes. In general, applications that use a

/// <see cref="IScheduler" /> will not have use for this mechanism.

/// </summary>

/// <seealso cref="IScheduler" />

/// <seealso cref="IJob" />

/// <seealso cref="JobExecutionContext" />

/// <seealso cref="JobExecutionException" />

/// <seealso cref="ITriggerListener" />

/// <author>James House</author>

public interface IJobListener

{

/// <summary>

/// Get the name of the <see cref="IJobListener" />.

/// </summary>

string Name { get; }

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="JobDetail" />

/// is about to be executed (an associated <see cref="Trigger" />

/// has occured).

/// <p>

/// This method will not be invoked if the execution of the Job was vetoed

/// by a <see cref="ITriggerListener" />.

/// </p>

/// </summary>

/// <seealso cref="JobExecutionVetoed(JobExecutionContext)" />

void JobToBeExecuted(JobExecutionContext context);

/// <summary>

/// Called by the <see cref="IScheduler" /> when a <see cref="JobDetail" />

/// was about to be executed (an associated <see cref="Trigger" />

/// has occured), but a <see cref="ITriggerListener" /> vetoed it's

/// execution.

/// </summary>

/// <seealso cref="JobToBeExecuted(JobExecutionContext)" />

void JobExecutionVetoed(JobExecutionContext context);

/// <summary>

/// Called by the <see cref="IScheduler" /> after a <see cref="JobDetail" />

/// has been executed, and be for the associated <see cref="Trigger" />'s

/// <see cref="Trigger.Triggered" /> method has been called.

/// </summary>

void JobWasExecuted(JobExecutionContext context, JobExecutionException jobException);

}

使用你自定义的监听器

创建监听器很简单，创建一个实现Quartz.ITriggerListener或（和）Quartz.IJobListener的接口。监听器然后在执行的时候注册到scheduler中，而且必须给定一个名字（或者，它们必须通过他们的Name属性来介绍自己）。监听器可以被注册为“全局”的或者“非全局”。“全局”监听器接收所有triggers/jobs产生的事件，而“非全局”监听器只接受那些通过TriggerListenerNames属性 或 JobListenerNames()方法显式指定监听器名的triggers/jobs所产生的事件。

正如上面所说的那样，监听器在运行时向scheduler注册，并且不被存储在jobs 和triggers的JobStore中。Jobs和Trigger只存储了与他们相关的监听器的名字。因此，每次应用运行的时候，都需要向scheduler重新注册监听器。

向 Scheduler中加入一个JobListener

scheduler.AddGlobalJobListener(myJobListener);

或者

scheduler.AddJobListener(myJobListener);

Quartz的大多数用户不使用监听器，但是当应用需要创建事件通知而Job本身不能显式通知应用，则使用监听器非常方便。