springboot 通过SchedulingConfigurer实现多定时任务注册及动态修改执行周期

Spring 中定时任务有两种实现方式:
1.@Scheduled(cron表达式)
2.基于SchedulingConfigurer注册定时任务
这两者的区别主要有
1.@Scheduled不支持动态修改定时周期，只能停止服务器，修改cron表达式，再启动服务器；SchedulingConfigurer可以动态修改
2.@Scheduled只能是单线程，而SchedulingConfigurer默认是单线程，可以通过添加线程池，实现多线程下定时任务的运行

import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.stereotype.Component;

import java.util.concurrent.Executors;

@Component
@EnableScheduling
public class Task implements SchedulingConfigurer {
    @Override
    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {

        //设置线程池
        scheduledTaskRegistrar.setScheduler(Executors.newScheduledThreadPool(20));
        //taskConfig中配置定时任务的相关信息
        TaskConfig taskConfig = dutyConfigs.get(taskType);
        //异步任务
        Runnable runnable = () -> createByConfig(taskConfig);
        Trigger trigger = triggerContext -> {
            CronTrigger cronTrigger = new CronTrigger(taskConfig.getCron());
            return cronTrigger.nextExecutionTime(triggerContext);
        };
        scheduledTaskRegistrar.addTriggerTask(runnable, trigger);
    }
}