java 动态读取数据库执行定时任务

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
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 org.springframework.util.StopWatch;
import java.time.LocalDateTime;

@Component
@EnableScheduling
@Configuration
public class TestScheduled implements SchedulingConfigurer {
    @Autowired
    private MapperDao mapperDao;

    @Override
    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
        scheduledTaskRegistrar.addTriggerTask(
                //1.添加任务内容
                this::scheduleTask,
                //2.设置执行周期
                triggerContext -> {
                    //2.1 从数据库获取执行周期
                    CronInfo cronInfo= mapperDao.findById(20);
                    String cron = cronInfo.getCron();
                    //2.2 合法性校验.
                    if (StringUtils.isEmpty(cron)) {
                        System.out.println("null");
                    }
                    //2.3 返回执行周期(Date)
                    return new CronTrigger(cron).nextExecutionTime(triggerContext);
                }
        );
       
    }

    public void scheduleTask() {
        StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        System.out.println("开始执行业务：" + LocalDateTime.now());
        for (int i = 0; i < 10; i++) {
            System.out.println("==>" + i);

        }
        stopWatch.stop();
        System.out.println(stopWatch.getTotalTimeSeconds());
    }
}