Spring Task实现定时任务的示例

@SpringBootApplication
@MapperScan("com.hospital.mapper")
@EnableCaching
@EnableScheduling  // 开启定时任务
public class SpringBootSystemApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootSystemApplication.class, args);
    }
}

package com.example.task;
import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.example.entity.Appointment;
import com.example.mapper.AppointmentMapper;
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.LocalDate;
import java.time.ZoneId;
import java.util.Date;
@Slf4j
@Component
public class AppointmentTask {
    @Autowired
    private AppointmentMapper appointmentMapper;
    /**
     * 每天凌晨1点执行，将已过期未就诊的预约状态改为"已过期"
     * cron表达式：秒 分 时 日 月 星期
     */
    @Scheduled(cron = "0 0 1 * * ?")
    public void cancelExpiredAppointments() {
        log.info("开始执行过期预约取消任务");
        // 获取当前日期之前的所有预约（预约日期小于今天）
        Date today = Date.from(LocalDate.now().atStartOfDay(ZoneId.systemDefault()).toInstant());
        LambdaUpdateWrapper<Appointment> wrapper = new LambdaUpdateWrapper<>();
        wrapper.lt(Appointment::getAppointmentDate, today)
               .eq(Appointment::getStatus, "已预约")
               .set(Appointment::getStatus, "已过期");
        int rows = appointmentMapper.update(null, wrapper);
        log.info("过期预约取消任务完成，共更新{}条记录", rows);
    }
    /**
     * 测试用：每30秒执行一次（取消后注释）
     */
    // @Scheduled(fixedDelay = 30000)
    // public void testTask() {
    //     log.info("定时任务测试");
    // }
}