我有一个Spring MVC Web应用程序，该应用程序具有Quartz Scheduler，用于每分钟执行一次特殊操作。为此，我开设了以下课程：
public class QuartzJobRunner {
public void run() {
log.debug("start");
log.debug("end");
}
}
和调度程序servlet中的XML配置：
<bean id="quartzJobRunner" class="com.demo.quartz.QuartzJobRunner" />
<bean id="methodInvokingJobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean"
p:targetObject-ref="quartzJobRunner" p:targetMethod="run"/>
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean"
p:jobDetail-ref="methodInvokingJobDetail" p:cronExpression="0 0/1 * * * ?"/>
<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean" p:triggers-ref="cronTrigger"/>
此处的预期行为是每分钟执行一次run方法。但是该方法执行了两次。
当我查看日志时，看到创建了两个调度程序：
2018-11-28 10:54:04.483 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Using default implementation for ThreadExecutor
2018-11-28 10:54:04.518 INFO [on(5)-127.0.0.1] org.quartz.core.SchedulerSignalerImpl.<init> Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl
2018-11-28 10:54:04.519 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.<init> Quartz Scheduler v.2.3.0 created.
2018-11-28 10:54:04.520 INFO [on(5)-127.0.0.1] org.quartz.simpl.RAMJobStore.initialize RAMJobStore initialized.
2018-11-28 10:54:04.522 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.initialize Scheduler meta-data: Quartz Scheduler (v2.3.0) 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' with instanceId 'NON_CLUSTERED'
Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
NOT STARTED.
Currently in standby mode.
Number of jobs executed: 0
Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads.
Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered.
2018-11-28 10:54:04.522 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Quartz scheduler 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' initialized from an externally provided properties instance.
2018-11-28 10:54:04.522 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Quartz scheduler version: 2.3.0
2018-11-28 10:54:04.525 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.setJobFactory JobFactory set to: org.springframework.scheduling.quartz.AdaptableJobFactory@4e6e5412
2018-11-28 10:54:04.569 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.start Scheduler org.springframework.scheduling.quartz.SchedulerFactoryBean#0_$_NON_CLUSTERED started.
2018-11-28 10:54:04.570 DEBUG [SchedulerThread] org.quartz.core.QuartzSchedulerThread.run batch acquisition of 0 triggers
2018-11-28 10:54:04.842 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Using default implementation for ThreadExecutor
2018-11-28 10:54:04.844 INFO [on(5)-127.0.0.1] org.quartz.core.SchedulerSignalerImpl.<init> Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl
2018-11-28 10:54:04.844 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.<init> Quartz Scheduler v.2.3.0 created.
2018-11-28 10:54:04.845 INFO [on(5)-127.0.0.1] org.quartz.simpl.RAMJobStore.initialize RAMJobStore initialized.
2018-11-28 10:54:04.845 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.initialize Scheduler meta-data: Quartz Scheduler (v2.3.0) 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' with instanceId 'NON_CLUSTERED'
Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
NOT STARTED.
Currently in standby mode.
Number of jobs executed: 0
Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads.
Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered.
2018-11-28 10:54:04.845 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Quartz scheduler 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' initialized from an externally provided properties instance.
2018-11-28 10:54:04.846 INFO [on(5)-127.0.0.1] org.quartz.impl.StdSchedulerFactory.instantiate Quartz scheduler version: 2.3.0
2018-11-28 10:54:04.846 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.setJobFactory JobFactory set to: org.springframework.scheduling.quartz.AdaptableJobFactory@27473d57
2018-11-28 10:54:04.864 DEBUG [SchedulerThread] org.quartz.core.QuartzSchedulerThread.run batch acquisition of 0 triggers
2018-11-28 10:54:04.864 INFO [on(5)-127.0.0.1] org.quartz.core.QuartzScheduler.start Scheduler org.springframework.scheduling.quartz.SchedulerFactoryBean#0_$_NON_CLUSTERED started.
这可能是什么原因？这里类似的问题没有明确的答案。