Springboot使用@Scheduled配置定时任务

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本文链接： https://blog.csdn.net/a787373009/article/details/101631260

Springboot使用@Scheduled配置定时任务

串行方式

使用的注解： @Scheduled
应用启动类添加注解：@EnableScheduling
代码示例：

package com.bin.kong.csdnspider.job;
import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component
@Slf4j
public class TestJob {
    @Scheduled(cron = "0/5 * * * * ?")
    public void exec() {
        log.info("Hello World!");
    }
}

打印日志如下：

2019-09-28 19:02:15.002 INFO 40178 — [ scheduling-1] com.bin.kong.csdnspider.job.TestJob : Hello World!
2019-09-28 19:02:20.001 INFO 40178 — [ scheduling-1] com.bin.kong.csdnspider.job.TestJob : Hello World!
2019-09-28 19:02:25.003 INFO 40178 — [ scheduling-1] com.bin.kong.csdnspider.job.TestJob : Hello World!

定时任务Cron配置可参考：https://www.cnblogs.com/linjiqin/archive/2013/07/08/3178452.html

并行执行

串行执行的时候，可能会出现线程阻塞导致执行延时的情况.
代码示例：

package com.bin.kong.csdnspider.job;

import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class TestJob {

    @Scheduled(cron = "0/5 * * * * ?")
    public void exec() {
        try {
            Thread.sleep(1000*10);
            log.info("Hello World!");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Scheduled(cron = "0/5 * * * * ?")
    public void exec2() {
        log.info("World Hello!" );
    }
}

结果打印，exec2的执行时间延时变成了15秒：

解决办法

1.使用线程池的方式：
配置方法可参考： Springboot线程池配置管理
代码示例：

package com.bin.kong.csdnspider.job;

import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class TestJob {

    @Scheduled(cron = "0/5 * * * * ?")
    public void exec() {
        try {
            Thread.sleep(1000*10);
            log.info("Hello World!");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Scheduled(cron = "0/5 * * * * ?")
    @Async("threadExecutor")
    public void exec2() {
        log.info("World Hello!" );
    }
}

2.使用Executors的方式

代码示例：

package com.bin.kong.csdnspider.job;

import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

@Component
@Slf4j
public class TestJob {

    @Scheduled(cron = "0/5 * * * * ?")
    public void exec() {
        try {
            Thread.sleep(1000 * 10);
            log.info("Hello World!");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Scheduled(cron = "0/5 * * * * ?")
    public void exec2() {
        ExecutorService service = Executors.newFixedThreadPool(5);
        service.execute(() -> {
            log.info("World Hello!");
        });
    }
}

3.将Scheduled配置成多线程执行的方式
示例代码：

package com.bin.kong.csdnspider.job;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;

import java.util.concurrent.Executors;

@Configuration
public class ScheduleConfig implements SchedulingConfigurer {
    @Override
    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
        scheduledTaskRegistrar.setScheduler(Executors.newScheduledThreadPool(5));
    }
}