Timed out while waiting for executor ‘taskScheduler‘ to terminate

使用@Scheduled 注解，我们一般会为其配置上一个线程池，我在写一个简单demo的时候，发现配上线程池后，关闭程序时，会打印出如下日志，

2021-07-12 23:50:10.381 [tid: ][skId: ] [SpringContextShutdownHook] INFO o.s.s.c.ThreadPoolTaskScheduler:218 - Shutting down ExecutorService ‘taskScheduler’
2021-07-12 23:50:12.387 [tid: ][skId: ] [SpringContextShutdownHook] WARN o.s.s.c.ThreadPoolTaskScheduler:256 - Timed out while waiting for executor ‘taskScheduler’ to terminate
2021-07-12 23:50:12.387 [tid: ][skId: ] [SpringContextShutdownHook] INFO o.s.s.c.ThreadPoolTaskScheduler:218 - Shutting down ExecutorService ‘taskScheduler’
2021-07-12 23:50:14.391 [tid: ][skId: ] [SpringContextShutdownHook] WARN o.s.s.c.ThreadPoolTaskScheduler:256 - Timed out while waiting for executor ‘taskScheduler’ to terminate
2021-07-12 23:50:14.405 [tid: ][skId: ] [SpringContextShutdownHook] INFO c.z.hikari.HikariDataSource:350 - village_test-POOL - Shutdown initiated…
2021-07-12 23:50:14.419 [tid: ][skId: ] [SpringContextShutdownHook] INFO c.z.hikari.HikariDataSource:352 - village_test-POOL - Shutdown completed.

我的线程池配置如下

	@Bean(destroyMethod = "shutdown")
    public ThreadPoolTaskScheduler taskScheduler() {
        ThreadPoolTaskScheduler executor = new ThreadPoolTaskScheduler();
        executor.setPoolSize(2);
        executor.setThreadNamePrefix("selfSchedule@");
        executor.setAwaitTerminationSeconds(2);
        executor.setWaitForTasksToCompleteOnShutdown(true);
        return executor;
    }

我要执行的任务，其实只是一个很简单的遍历任务，循环一次耗时远小于1s，我给的等待时间有2s，为什么还是会报超时问题呢？

查询了下Stack Overflow ，记录下原因。

Because by default the ScheduledThreadPoolExecutor will wait for all delayed scheduled tasks to finish executing, even if scheduled tasks aren’t running at that time.

即使任务并不在执行中，ScheduledThreadPoolExecutor还是会等待任务结束执行。

解决方式如下：

@Bean
public TaskScheduler taskScheduler() {
    ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler() {
        private static final long serialVersionUID = -1L;
        @Override
        public void destroy() {
            this.getScheduledThreadPoolExecutor().setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
            super.destroy();
        }
    };
    scheduler.setWaitForTasksToCompleteOnShutdown(true);
    scheduler.setAwaitTerminationSeconds(60);
    return scheduler;
}

原文地址,我搜索了一圈没找到答案，特此记录下。