如何动态修改spring中定时任务的调度策略(2)_spring scheduler实现修改调度时间-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_45701550/article/details/136858875

本文探讨如何在Spring中为@Scheduled定义自定义线程池，并分析如何实现实时修改定时任务调度策略。虽然Spring默认不支持动态调整，但作者提出了一种通过自定义注解和接口来实现不停服更新任务调度的方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

上一篇文章中我们一下走读了一下spring中实现@Scheduled的源码，想必你对spring中实现定时调度的原理更加了解吧，文末我们两个问题，
1.spring在进行定时调度时，使用的线程池是默认，那么这个默认的线程池的配置是怎样的呢？

2.如何动态调整调度策略。

接下来我们详细分析一下这两个问题。

为@Scheduled定义一个线程池

spring在执行调度任务前，会按照好一定的策略，寻找一个可用的线程池来执行调度任务，寻找这个线程池的过程如下:

private void finishRegistration() {
   
		if (this.scheduler != null) {
   
			this.registrar.setScheduler(this.scheduler);
		}

		if (this.beanFactory instanceof ListableBeanFactory) {
   
			Map<String, SchedulingConfigurer> beans =
					((ListableBeanFactory) this.beanFactory).getBeansOfType(SchedulingConfigurer.class);
			List<SchedulingConfigurer> configurers = new ArrayList<>(beans.values());
			AnnotationAwareOrderComparator.sort(configurers);
			// 1.使用SchedulingConfigurer进行配置
			for (SchedulingConfigurer configurer : configurers) {
   
				configurer.configureTasks(this.registrar);
			}
		}

		if (this.registrar.hasTasks() && this.registrar.getScheduler() == null) {
   
			Assert.state(this.beanFactory != null, "BeanFactory must be set to find scheduler by type");
			try {
   
				// Search for TaskScheduler bean... // 2.寻找一个类型为 TaskScheduler 的bean
				this.registrar.setTaskScheduler(resolveSchedulerBean(this.beanFactory, TaskScheduler.class, false));
			}
			catch (NoUniqueBeanDefinitionException ex) {
   
				if (logger.isTraceEnabled()) {
   
					logger.trace("Could not find unique TaskScheduler bean - attempting to resolve by name: " +
							ex.getMessage());
				}
				try {
   
					this.registrar.setTaskScheduler(resolveSchedulerBean(this.beanFactory, TaskScheduler.class, true));
				}
				catch (NoSuchBeanDefinitionException ex2) {
   
					if (logger.isInfoEnabled()) {
   
						logger.info("More than one TaskScheduler bean exists within the context, and " +
								"none is named 'taskScheduler'. Mark one of them as primary or name it 'taskScheduler' " +
								"(possibly as an alias); or implement the SchedulingConfigurer interface and call " +
								"ScheduledTaskRegistrar#setScheduler explicitly within the configureTasks() callback: " +
								ex.getBeanNamesFound());
					}
				}
			}
			catch (NoSuchBeanDefinitionException ex) {
   
				if (logger.isTraceEnabled()) {
   
					logger.trace("Could not find default TaskScheduler bean - attempting to find ScheduledExecutorService: " +
							ex.getMessage());
				}
				// Search for ScheduledExecutorService bean next...
				try {
   
					this.registrar.setScheduler(resolveSchedulerBean(this.beanFactory, ScheduledExecutorService.class, false));
				}
				catch (NoUniqueBeanDefinitionException ex2) {
   
					if (logger.isTraceEnabled()) {
   
						logger.trace("Could not find unique Sch