springboot + @scheduled 多任务并发

Posted 2020-10-22 那啥快看

一、问题

项目采用springboot搭建，想给方法添加@Scheduled注解，实现两个定时任务。可是运行发现，两个task并没有并发执行，而是执行完一个task才会执行另外一个。上代码：

package com.autohome.contentplatform.tasks;
 
import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
 
@Component
@Configurable
@EnableScheduling
public class task1 {
     @Scheduled(cron = "0/5 * *  * * ? ")
     public void startSchedule() {
         System.out.println("===========1=>");
         try {
             for(int i=1;i<=10;i++){
                 System.out.println("=1==>"+i);
                 Thread.sleep(1000);
             }
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
     }
     @Scheduled(cron = "0/5 * *  * * ? ")
     public void startSchedule2() {
         for(int i=1;i<=10;i++){
             System.out.println("=2==>"+i);
             try {
                 Thread.sleep(1000);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
         }
     }
}

运行发现任务没有并行执行。

二、解决

给类添加注解@EnableAsync，并给方法添加注解@Async。

@Component
@Configurable
@EnableScheduling
@EnableAsync
public class DemoTask {
     @Async
     @Scheduled(cron = "0/5 * *  * * ? ")
     public void startSchedule() {
         System.out.println("===========1=>");
         try {
             for(int i=1;i<=10;i++){
                 System.out.println("=1==>"+i);
                 Thread.sleep(1000);
             }
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
     }
 
    @Async
     @Scheduled(cron = "0/5 * *  * * ? ")
     public void startSchedule2() {
         for(int i=1;i<=10;i++){
             System.out.println("=2==>"+i);
             try {
                 Thread.sleep(1000);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
         }
     }
}

再次运行，发现两个任务可以并发执行了。

三、参考资料：

https://docs.spring.io/spring/docs/3.2.x/spring-framework-reference/html/scheduling.html