Springboot动态定时任务

1、动态定时任务

重点在于Trigger。采用Cron格式设置时间，时间存在redis中。比如key为crontime，value设置为10分钟，

即crontime = "0 0/10 * * * ? "。在redis中人为修改时间，任务会在下个定时周期生效，不必重新启动程序。

package com.exm.springmybatis.scheduler.task;

import com.exm.springmybatis.service.RedisServer;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import java.util.Date;

/**
 * 重点在Trigger
 * Created by on xiabaobao 2018/11/19 16:40
 */
@Slf4j
@Component
public class DynamicTask implements SchedulingConfigurer {
    @Autowired
    private RedisServer redisServer;
    private static String cron;

    @Override
    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
        scheduledTaskRegistrar.addTriggerTask(doTask(), getTrigger());
    }

    private Runnable doTask(){
        return new Runnable() {
            @Override
            public void run() {
                log.info("**** mytask first to run: {}",new Date(System.currentTimeMillis()));
            }
        };
    }

    private Trigger getTrigger(){
        return new Trigger() {
            @Override
            public Date nextExecutionTime(TriggerContext triggerContext) {
                CronTrigger trigger = new CronTrigger(gerCron());
                return trigger.nextExecutionTime(triggerContext);
            }
        };
    }

    public String gerCron(){
        String newCron = redisServer.get("crontime");
        log.info("*** get time: {} ",newCron);
        if(StringUtils.isEmpty(newCron)){
            log.info(" get cron time fail");
        }else if(!newCron.equals(cron)){
            log.info("newCrontime: {} <-> oldCrontime: {}", newCron, cron);
            cron = newCron;
        }

        return  cron;
    }


}