springboot计划任务@EnableScheduling和@Scheduled

package ch2.scheduler;
 //时间处理，时间格式化
 import java.util.Date;
 import java.text.SimpleDateFormat;
 //spring计划任务声明(针对方法声明)
 import org.springframework.scheduling.annotation.Scheduled;
 //spring组件声明
 import org.springframework.stereotype.Service;
 //组件什么
 @Service
 public class SchedulerService {
     //创建日期模板
     private static final SimpleDateFormat  dateFormat = new mpleDateFormat("HH::MM::ss");
     //每5秒钟执行一次
     @Scheduled(fixedRate = 5000)
     public void reportCurrentTime()
     {
         System.out.println("每五秒执行一次: " + dateFormat.format( new Date() ));
     }
     //按照cron属性指定执行时间：秒分时
     @Scheduled(cron = "0 34 18 ? * *")
     public void fixTimeExecution()
     {
         System.out.println("在指定的时间内执行: " + dateFormat.format( new Date()) );
     }  
 }

package ch2.scheduler;
 //自动引入包
 import org.springframework.context.annotation.ComponentScan;
 //配置类声明
 import org.springframework.context.annotation.Configuration;
 //计划任务类声明
 import org.springframework.scheduling.annotation.EnableScheduling;
 //配置类声明
 @Configuration
 //自动引入包
 @ComponentScan("ch2.scheduler")
 //通过@EnableScheduling开启对计划任务的支持
 @EnableScheduling
 public class TaskSchedulerConfig {  
 }     

package ch2.scheduler;
 //引入容器
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 public class Main {
     public static void main(String[] args)
     {
         AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(TaskSchedulerConfig.class);
         //SchedulerService schedulerService  = context.getBean(SchedulerService.class);  
     }
 }

@Scheduled(cron = "0/1 * * * * ? ")
public void deleteFile() throws InterruptedException {
    log.info("111delete success, time:" + new Date().toString());
    Thread.sleep(1000 * 5);//模拟长时间执行，比如IO操作，http请求
}
@Scheduled(cron = "0/1 * * * * ? ")
public void syncFile() {
    log.info("222sync success, time:" + new Date().toString());
}

//构建一个合理的线程池也是一个关键，否则提交的任务也会在自己构建的线程池中阻塞
ExecutorService service = Executors.newFixedThreadPool(5);
@Scheduled(cron = "0/1 * * * * ? ")
public void deleteFile() {
    service.execute(() -> {
        log.info("111delete success, time:" + new Date().toString());
        try {
            Thread.sleep(1000 * 5);//改成异步执行后，就算你再耗时也不会印象到后续任务的定时调度了
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    });
}
@Scheduled(cron = "0/1 * * * * ? ")
public void syncFile() {
    service.execute(()->{
        log.info("222sync success, time:" + new Date().toString());
    });
} 

@Configuration
public class ScheduleConfig implements SchedulingConfigurer {
    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        //当然了，这里设置的线程池是corePoolSize也是很关键了，自己根据业务需求设定
        taskRegistrar.setScheduler(Executors.newScheduledThreadPool(5));
        /**为什么这么说呢？
        假设你有4个任务需要每隔1秒执行，而其中三个都是比较耗时的操作可能需要10多秒，而你上面的语句是这样写的：
        taskRegistrar.setScheduler(Executors.newScheduledThreadPool(3));
        那么仍然可能导致最后一个任务被阻塞不能定时执行
        **/
    }
}