我有多个带有@Scheduled
注释的组件,我发现Spring一次只启动一个,即使它们被安排在同一时间运行。
我的用例如下。我希望每个@Scheduled注释都在自己的线程中运行,但每个线程只运行一次。
鉴于这个带有两个调度程序的伪代码:
@Scheduled(cron = "0 * * * * *") //run every minute
public void methodA() {
log.info("Running method A");
executeLongRunningJob("Finished method A");
}
@Scheduled(cron = "0 * * * * *") //run every minute
public void methodB() {
log.info("Running method B");
executeLongRunningJob("Finished method B");
}
private void executeLongRunningJob(String msg) {
Thread.sleep(70 seconds);
System.out.println(msg);
}
请注意,任务所需的时间比计划运行的调度程序要长。这很关键。我不希望调度程序在完成运行之前重新启动。
运行此代码开箱即可获得此输出:
Running method A
Finished method A
Running method B
Finished method B
Running method A
Finished method A
Running method B
Finished method B
... and so on
很明显,它在一个线程中运行两个调度程序。
当我将@Async
放在我的昂贵方法上时,我几乎得到了正确的行为,除了在新的调度程序启动之前没有完成昂贵的方法。
Running method A
Running method B
Running method A
Running method B
Finished method A
Finished method B
... and so on
我想要的是这个输出:
Running method A
Running method B
Finished method A
Finished method B
Running method A
Running method B
Finished method A
Finished method B
... and so on
我怎样才能做到这一点? 我希望每个调度程序同时运行,但等到它完成后再允许再次运行。 请记住,我有两个以上的调度程序在相同且有时不同的时间运行。
答案 0 :(得分:11)
您是对的 - 默认情况下,调度程序使用大小为1的线程池,因此每个任务都按顺序处理。您可以通过配置具有所需池大小的TaskScheduler
bean来实现。请考虑以下示例:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import java.util.Date;
@SpringBootApplication
@EnableScheduling
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Bean
public TaskScheduler taskScheduler() {
final ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
scheduler.setPoolSize(10);
return scheduler;
}
@Scheduled(fixedDelay = 2 * 1000L, initialDelay = 3 * 1000L)
public void scheduled1() throws InterruptedException {
System.out.println(new Date() + " " + Thread.currentThread().getName() + ": scheduled1");
Thread.sleep(1000);
}
@Scheduled(fixedDelay = 3 * 1000L, initialDelay = 3 * 1000L)
public void scheduled2() throws InterruptedException {
System.out.println(new Date() + " " + Thread.currentThread().getName() + ": scheduled2");
Thread.sleep(1000);
}
}
它将在单独的线程中运行每个计划任务,例如:
Tue Jul 18 20:21:50 CEST 2017 taskScheduler-1: scheduled2
Tue Jul 18 20:21:50 CEST 2017 taskScheduler-2: scheduled1
Tue Jul 18 20:21:53 CEST 2017 taskScheduler-1: scheduled1
Tue Jul 18 20:21:54 CEST 2017 taskScheduler-3: scheduled2
Tue Jul 18 20:21:56 CEST 2017 taskScheduler-2: scheduled1
Tue Jul 18 20:21:58 CEST 2017 taskScheduler-4: scheduled2
Tue Jul 18 20:21:59 CEST 2017 taskScheduler-1: scheduled1