一、文档：
【cron表达式在线生成器】https://cron.qqe2.com/
二、案例： @EnableScheduling //开启任务调度 package com.sky.task;import com.sky.entity.Orders;import com.sky.mapper.OrderMapper;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Component;import java.time.LocalDateTime;import java.util.List;/*** 定时任务类，定时处理订单状态*/@Component@Slf4jpublic class OrderTask {@Autowiredprivate OrderMapper orderMapper;/*** 处理超时订单的方法*/@Scheduled(cron = "0 * * * * ? ") //每分钟触发一次public void processTimeoutOrder(){log.info("定时处理超时订单：{}", LocalDateTime.now());LocalDateTime time = LocalDateTime.now().plusMinutes(-15);// select * from orders where status = ? and order_time < (当前时间 - 15分钟)List<Orders> ordersList = orderMapper.getByStatusAndOrderTimeLT(Orders.PENDING_PAYMENT, time);if(ordersList != null && ordersList.size() > 0){for (Orders orders : ordersList) {orders.setStatus(Orders.CANCELLED);orders.setCancelReason("订单超时，自动取消");orders.setCancelTime(LocalDateTime.now());orderMapper.update(orders);}}}/*** 处理一直处于派送中状态的订单*/@Scheduled(cron = "0 0 1 * * ?") //每天凌晨1点触发一次public void processDeliveryOrder(){log.info("定时处理处于派送中的订单：{}",LocalDateTime.now());LocalDateTime time = LocalDateTime.now().plusMinutes(-60);List<Orders> ordersList = orderMapper.getByStatusAndOrderTimeLT(Orders.DELIVERY_IN_PROGRESS, time);if(ordersList != null && ordersList.size() > 0){for (Orders orders : ordersList) {orders.setStatus(Orders.COMPLETED);orderMapper.update(orders);}}}}
