Cron 表达式生成与解析器

# 显式声明 PATH 环境变量，结合 flock 文件锁与 stdout/stderr 联合重定向
SHELL=/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

0 2 * * * /usr/bin/flock -n /var/lock/db_backup.lock /opt/scripts/backup.sh >> /var/log/backup.log 2>&1

apiVersion: batch/v1
kind: CronJob
metadata:
  name: telemetry-sync
spec:
  schedule: "*/15 * * * *"
  concurrencyPolicy: Forbid
  successfulJobsHistoryLimit: 3
  failedJobsHistoryLimit: 1
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: sync-worker
            image: registry.example.com/worker:v1.4
          restartPolicy: OnFailure

import cron from 'node-cron';

// 显式指定 IANA 标准时区，规避宿主机本地时钟偏移影响
cron.schedule('0 9 * * 1-5', () => {
  console.log('执行工作日早间业务批处理任务');
}, {
  scheduled: true,
  timezone: 'Asia/Shanghai'
});

from datetime import datetime, timezone
from croniter import croniter

base_time = datetime.now(timezone.utc)
iter = croniter('0 2 * * *', base_time)

# 计算并打印接下来的三次执行时间点
for _ in range(3):
    next_run = iter.get_next(datetime)
    print(f"预计下一次 UTC 执行时刻: {next_run.isoformat()}")

package main

import (
    "fmt"
    "github.com/robfig/cron/v3"
)

func main() {
    // 使用默认 5 位标准解析器（不含秒）
    c := cron.New()
    _, err := c.AddFunc("0 0 1 * *", func() {
        fmt.Println("启动月度财务账单对账批处理")
    })
    if err != nil {
        panic(err)
    }
    c.Start()
    select {}
}

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class ScheduledTasks {

    // Spring 6 位规范：秒 分 时 日 月 周
    @Scheduled(cron = "0 0 2 * * ?", zone = "Asia/Shanghai")
    public void executeNightlyBatch() {
        // 核心批处理逻辑
    }
}