解析spring schedule 任务调度

Spring在schedule这块支持JDK Timer、concurrent、quartz三种，这三种任务调度方案在实现机制和调用方法上都不同，但spring通过对其包装，使得基于spring能用统一的配置和编码风格来使用这三种schedule方案。

总得来说这三种schedule都是基于scheduler->trigger->job的基本流程，因此spring通过TimerFactoryBean、ScheduledExecutorFactoryBean和SchedulerFactoryBean分别实现JDK Timer、concurrent和quartz的基本流程。主要逻辑如下代码所示：

TimerFactoryBean

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1. public void afterPropertiesSet() {  
2.         logger.info("Initializing Timer");  
3.         this.timer = createTimer(this.beanName, this.daemon);  
4.         // Register specified ScheduledTimerTasks, if necessary.  
5.         if (!ObjectUtils.isEmpty(this.scheduledTimerTasks)) {  
6. //注册task和timer          registerTasks(this.scheduledTimerTasks, this.timer);  
7.         }  
8.     }  

public void afterPropertiesSet() {logger.info("Initializing Timer");this.timer = createTimer(this.beanName, this.daemon);// Register specified ScheduledTimerTasks, if necessary.if (!ObjectUtils.isEmpty(this.scheduledTimerTasks)) {//注册task和timerregisterTasks(this.scheduledTimerTasks, this.timer);}}

ScheduledExecutorFactoryBean

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1. public void afterPropertiesSet() {  
2.         if (logger.isInfoEnabled()) {  
3.             logger.info("Initializing ScheduledExecutorService" +  
4.                     (this.beanName != null ? " '" + this.beanName + "'" : ""));  
5.         }  
6.         ScheduledExecutorService executor =  
7.                 createExecutor(this.poolSize, this.threadFactory, this.rejectedExecutionHandler);  
8.         // Register specified ScheduledExecutorTasks, if necessary.  
9.         if (!ObjectUtils.isEmpty(this.scheduledExecutorTasks)) {  
10.             registerTasks(this.scheduledExecutorTasks, executor);  
11.         }  
12.         // Wrap executor with an unconfigurable decorator.  
13.         this.executor = (this.exposeUnconfigurableExecutor ?  
14.                 Executors.unconfigurableScheduledExecutorService(executor) : executor);  
15.     }  

public void afterPropertiesSet() {if (logger.isInfoEnabled()) {logger.info("Initializing ScheduledExecutorService" +(this.beanName != null ? " '" + this.beanName + "'" : ""));}ScheduledExecutorService executor =createExecutor(this.poolSize, this.threadFactory, this.rejectedExecutionHandler);// Register specified ScheduledExecutorTasks, if necessary.if (!ObjectUtils.isEmpty(this.scheduledExecutorTasks)) {registerTasks(this.scheduledExecutorTasks, executor);}// Wrap executor with an unconfigurable decorator.this.executor = (this.exposeUnconfigurableExecutor ?Executors.unconfigurableScheduledExecutorService(executor) : executor);}

SchedulerFactoryBean

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1. public void afterPropertiesSet() throws Exception {  
2.     .....  
3.         // 初始化sceduler   
4.         initSchedulerFactory(schedulerFactory);  
5.         this.scheduler = createScheduler(schedulerFactory, this.schedulerName);  
6.                 //注册listener、trigger和job   
7.         registerListeners();  
8.         registerJobsAndTriggers();  
9.        ......  
10.                 //启动scheduler   
11.         startScheduler(this.scheduler, this.startupDelay);  
12.        ......  
13.         }  
14.     }  

public void afterPropertiesSet() throws Exception {.....// 初始化scedulerinitSchedulerFactory(schedulerFactory);this.scheduler = createScheduler(schedulerFactory, this.schedulerName); //注册listener、trigger和jobregisterListeners();registerJobsAndTriggers(); ...... //启动schedulerstartScheduler(this.scheduler, this.startupDelay); ......}}

顺着scheduler->trigger->job的思路，Spring又分别对JDK Timer、concurrent、quartz的trigger进行了封装，暴露出时间调度的配置参数，三种封装类分别为ScheduledTimerTask、ScheduledExecutorTask和CronTriggerBean+SimpleTriggerBean。三种trigger封装类分别根据实现机制的特点暴露出时间调度配置并串联起scheduler和具体job任务