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
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timer registerTasks(this.scheduledTimerTasks, this.timer); } }
ScheduledExecutorFactoryBean
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
public void afterPropertiesSet() throws Exception { ..... // 初始化sceduler initSchedulerFactory(schedulerFactory); this.scheduler = createScheduler(schedulerFactory, this.schedulerName); //注册listener、trigger和job registerListeners(); registerJobsAndTriggers(); ...... //启动scheduler startScheduler(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