Spring动态添加定时任务的实现思路

package com.huan.study.task.jobs.tasks;

import lombok.extern.slf4j.slf4j;

import org.springframework.beans.factory.initializingbean;

import org.springframework.beans.factory.annotation.autowired;

import org.springframework.scheduling.concurrent.threadpooltaskscheduler;

import org.springframework.scheduling.support.cronexpression;

import org.springframework.scheduling.support.crontrigger;

import org.springframework.stereotype测试数据ponent;

import java.time.localdatetime;

import java.time.format.datetimeformatter;

import java.util.concurrent.scheduledfuture;

import java.util.concurrent.timeunit;

/**

  * @author huan.fu 2021/7/8 - 下午2:46

  */

@component

@slf4j

public class dynamiccrontask implements initializingbean {

     @autowired

     private threadpooltaskscheduler taskscheduler;

     private scheduledfuture<?> scheduledfuture;

     @override

     public void afterpropertiesset() throws exception {

         // 动态启动一个定时任务

         log.info( "注册一个定时任务:每隔1秒执行一次" );

         scheduledfuture = register( "* * * * * ?" );

         // 取消一个调度

         new thread(() -> {

             try {

                 timeunit.seconds.sleep( 5 );

                 log.info( "取消调度" );

                 scheduledfuture.cancel( false );

                 log.info( "取消结果:" + scheduledfuture.iscancelled());

                 log.info( "重新注册一个定时任务:每隔2秒执行一次" );

                 register( "*/2 * * * * ?" );

             } catch (interruptedexception e) {

                 e.printstacktrace();

             }

         }).start();

     }

     private scheduledfuture<?> register(string cron) {

         // 高版本使用 cronexpression，低版本使用 cronsequencegenerator

         boolean validexpression = cronexpression.isvalidexpression(cron);

         log.info( "cron:[{}]是合法的吗:[{}]" , cron, validexpression);

         cronexpression expression = cronexpression.parse(cron);

         localdatetime nextexectime = expression.next(localdatetime.now());

         if ( null != nextexectime) {

             log.info( "定时任务下次执行的时间为:[{}]" , nextexectime.format(datetimeformatter.ofpattern( "yyyy-mm-dd hh:mm:ss" )));

         }

         return taskscheduler.schedule( new runnable() {

             @override

             public void run() {

                 log.info( "我执行了" );

             }

         }, new crontrigger(cron));

     }

}