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.
给定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,该任务所需的时间比计划的调度程序运行时间长.这很关键.我不希望调度程序在完成运行之前重新启动.
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
显然它在一个线程中运行两个调度程序.
当我把@Async放在我昂贵的方法上时,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
我怎么能做到这一点？
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.
解决方法
你没错 – 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.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
