SpringBoot使用@Scheduled實現(xiàn)定時任務(wù)的并行執(zhí)行

更新時間：2024年06月02日 15:37:02 作者：シ風(fēng)箏

在SpringBoot中,如果使用@Scheduled注解來定義多個定時任務(wù),默認情況下這些任務(wù)將會被安排在一個單線程的調(diào)度器中執(zhí)行,這意味著,這些任務(wù)將會串行執(zhí)行,而不是并行執(zhí)行,本文介紹了SpringBoot使用@Scheduled實現(xiàn)定時任務(wù)的并行執(zhí)行,需要的朋友可以參考下

引言

在SpringBoot中，如果使用@Scheduled注解來定義多個定時任務(wù)，默認情況下這些任務(wù)將會被安排在一個單線程的調(diào)度器中執(zhí)行。這意味著，這些任務(wù)將會串行執(zhí)行，而不是并行執(zhí)行。當(dāng)一個任務(wù)正在執(zhí)行時，其他被觸發(fā)的任務(wù)將會等待當(dāng)前任務(wù)完成后再開始執(zhí)行，這可能導(dǎo)致任務(wù)執(zhí)行上的阻塞，特別是當(dāng)某個任務(wù)執(zhí)行時間較長時，可能會延遲后續(xù)任務(wù)的啟動時間，影響定時任務(wù)的準時性。

1.問題代碼及測試結(jié)果

問題代碼：

    @Scheduled(cron = "*/1 * * * * *")
    public void a() throws InterruptedException {
        log.info("A Start {}!", System.currentTimeMillis());
        Thread.sleep(2000);
        log.info("A End {}!", System.currentTimeMillis());
    }

    @Scheduled(cron = "*/1 * * * * *")
    public void b() {
        log.info("B Start {}!", System.currentTimeMillis());
        log.info("B End {}!", System.currentTimeMillis());
    }

部分測試結(jié)果：

15:38:29.001 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716968309001!
15:38:29.001 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716968309001!
15:38:29.001 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716968309001!

15:38:31.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716968311003!
15:38:31.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716968311003!
15:38:31.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716968311003!

15:38:32.002 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716968312002!

15:38:34.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716968314003!
15:38:34.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716968314003!
15:38:34.003 [scheduling-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716968314003!

結(jié)果分析：

A和B是串行的。

2.定時任務(wù)實現(xiàn)并行

2.1 使用自定義線程池（添加類）

可以通過配置一個自定義的TaskScheduler或者ThreadPoolTaskScheduler來為@Scheduled任務(wù)提供一個線程池，從而允許多個任務(wù)并行執(zhí)行。例如，可以在配置類中定義一個ThreadPoolTaskScheduler Bean：

@Configuration
public class AsyncConfig {
    @Bean
    public ThreadPoolTaskScheduler taskScheduler() {
        ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
        // 設(shè)置線程池大小
        scheduler.setPoolSize(10); 
        scheduler.setThreadNamePrefix("my-scheduled-task-");
        return scheduler;
    }
}

并確保你的配置類被掃描到，且在@EnableScheduling注解的上下文中。

測試代碼：

    @Scheduled(cron = "*/1 * * * * *")
    public void a() throws InterruptedException {
        log.info("A Start {}!", System.currentTimeMillis());
        Thread.sleep(2000);
        log.info("A End {}!", System.currentTimeMillis());
    }

    @Scheduled(cron = "*/1 * * * * *")
    public void b() {
        log.info("B Start {}!", System.currentTimeMillis());
        log.info("B End {}!", System.currentTimeMillis());
    }

部分測試結(jié)果：

15:16:18.003 [my-scheduled-task-2] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716966978003!
15:16:18.003 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966978003!
15:16:18.003 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966978003!

15:16:19.002 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966979002!
15:16:19.002 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966979002!

15:16:20.004 [my-scheduled-task-2] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716966980004!
15:16:20.004 [my-scheduled-task-3] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966980004!
15:16:20.004 [my-scheduled-task-3] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966980004!

15:16:21.003 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716966981003!
15:16:21.003 [my-scheduled-task-4] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966981003!
15:16:21.003 [my-scheduled-task-4] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966981003!

15:16:22.001 [my-scheduled-task-2] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966982001!
15:16:22.001 [my-scheduled-task-2] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966982001!

15:16:23.004 [my-scheduled-task-1] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716966983004!
15:16:23.004 [my-scheduled-task-3] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716966983004!
15:16:23.004 [my-scheduled-task-3] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716966983004!

結(jié)果分析：

A和B是并行的；
A和A或者B和B是串行的。

2.2 使用異步處理（添加類和注解）

結(jié)合@Async注解和@EnableAsync可以使得每個@Scheduled任務(wù)在獨立的線程中異步執(zhí)行。
首先需要在配置類中啟用異步支持，并配置一個線程池，然后在每個定時任務(wù)方法上添加@Async注解。

@EnableAsync
@Configuration
public class AsyncConfig {
    @Bean
    public Executor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(10);
        executor.setMaxPoolSize(20);
        executor.setQueueCapacity(200);
        executor.setThreadNamePrefix("Async-");
        executor.initialize();
        return executor;
    }
}

測試代碼：

    @Async
    @Scheduled(cron = "*/1 * * * * *")
    public void a() throws InterruptedException {
        log.info("A Start {}!", System.currentTimeMillis());
        Thread.sleep(2000);
        log.info("A End {}!", System.currentTimeMillis());
    }

    @Async
    @Scheduled(cron = "*/1 * * * * *")
    public void b() {
        log.info("B Start {}!", System.currentTimeMillis());
        log.info("B End {}!", System.currentTimeMillis());
    }

部分測試結(jié)果：

15:26:52.008 [Async-2] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967612008!
15:26:52.008 [Async-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967612008!
15:26:52.009 [Async-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967612009!

15:26:53.002 [Async-4] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967613002!
15:26:53.002 [Async-3] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967613002!
15:26:53.002 [Async-3] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967613002!

15:26:54.001 [Async-6] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967614001!
15:26:54.001 [Async-5] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967614001!
15:26:54.001 [Async-5] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967614001!
15:26:54.010 [Async-2] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716967614010!

15:26:55.002 [Async-8] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967615002!
15:26:55.002 [Async-7] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967615002!
15:26:55.002 [Async-7] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967615002!
15:26:55.002 [Async-4] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716967615002!

15:26:56.001 [Async-10] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967616001!
15:26:56.001 [Async-9] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967616001!
15:26:56.001 [Async-9] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967616001!
15:26:56.002 [Async-6] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716967616002!

15:26:57.001 [Async-3] INFO  c.x.e.m.SchedulerTask - [a,44] - A Start 1716967617001!
15:26:57.001 [Async-1] INFO  c.x.e.m.SchedulerTask - [b,52] - B Start 1716967617001!
15:26:57.001 [Async-1] INFO  c.x.e.m.SchedulerTask - [b,53] - B End 1716967617001!
15:26:57.002 [Async-8] INFO  c.x.e.m.SchedulerTask - [a,46] - A End 1716967617002!

測試結(jié)果分析：

A和B是并行的；
A和A或者B和B也是并行的。

3.總結(jié)

到此這篇關(guān)于SpringBoot使用@Scheduled實現(xiàn)定時任務(wù)的并行執(zhí)行的文章就介紹到這了,更多相關(guān)SpringBoot @Scheduled任務(wù)并行執(zhí)行內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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