Java @Scheduled定时器用法解析

    @Scheduled(cron="0 0 21 * * ?") //每天晚上九点执行一次    21点
    public void taskCycle() throws  Exception{
        System.out.println("############定时校验代金券过期任务开始执行");
        }

@Scheduled(cron="0 0 21 * * ?") 

@Configuration
@EnableScheduling
public class ScheduleConfig implements SchedulingConfigurer {
    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.setScheduler(taskExecutor());
    }
    @Bean(destroyMethod="shutdown")
    public Executor taskExecutor() {
        return Executors.newScheduledThreadPool(2);
    }
}