quartz 定时器周期设定

V2EX = way to explore

V2EX 是一个关于分享和探索的地方

现在注册

已注册用户请登录

• 请不要在回答技术问题时复制粘贴 AI 生成的内容

这是一个创建于 1904 天前的主题，其中的信息可能已经有所发展或是发生改变。

"* * * */7 * ?"
请问这样是否是每七天执行一次呢？

Quartz

请问

定时

设定

11 条回复 • 2019-09-25 16:23:47 +08:00

airfling

2019-09-25 11:15:51 +08:00

那你为啥不直接直接设置为每周几执行一次

qian88199496

2019-09-25 11:17:10 +08:00

@airfling #1 因为想在启动的时候直接运行啊，相隔一周执行一次

airfling

2019-09-25 11:23:56 +08:00

@qian88199496 那你这样写就是每次启动都会执行一遍，如果出现上线问题，重启什么的就是每次重启都执行，这样写是没问题，不过不利于分布式部署和突发情况

qian88199496

2019-09-25 11:31:20 +08:00

就是为了收集分布式部署，服务器信息和应用信息，才想要这样设置

fuxinya

2019-09-25 11:48:57 +08:00 via Android

百度在线 cron 表达式

k9990009

2019-09-25 12:47:12 +08:00

你每天都跑，程序里判断要不要执行，不就好了

diyhi

2019-09-25 13:02:58 +08:00

这样?可以指定每周星期几

rancc

2019-09-25 13:06:17 +08:00

Expression Meaning
"0 0 12 * * ?" Fire at 12pm (noon) every day
"0 15 10 ? * *" Fire at 10:15am every day
"0 15 10 * * ?" Fire at 10:15am every day
"0 15 10 * * ? *" Fire at 10:15am every day
"0 15 10 * * ? 2005" Fire at 10:15am every day during the year 2005
"0 * 14 * * ?" Fire every minute starting at 2pm and ending at 2:59pm, every day
"0 0/5 14 * * ?" Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day
"0 0/5 14,18 * * ?" Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day
"0 0-5 14 * * ?" Fire every minute starting at 2pm and ending at 2:05pm, every day
"0 10,44 14 ? 3 WED" Fire at 2:10pm and at 2:44pm every Wednesday in the month of March.
"0 15 10 ? * MON-FRI" Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday
"0 15 10 15 * ?" Fire at 10:15am on the 15th day of every month
"0 15 10 L * ?" Fire at 10:15am on the last day of every month
"0 15 10 ? * 6L" Fire at 10:15am on the last Friday of every month
"0 15 10 ? * 6L" Fire at 10:15am on the last Friday of every month
"0 15 10 ? * 6L 2002-2005" Fire at 10:15am on every last Friday of every month during the years 2002, 2003, 2004 and 2005
"0 15 10 ? * 6#3" Fire at 10:15am on the third Friday of every month

Pay attention to the effects of '?' and '*' in the day-of-week and day-of-month fields!

rancc

2019-09-25 13:07:32 +08:00

接上条，所以需要指定时间。哪一分那一秒都要指定

zifangsky

2019-09-25 16:15:31 +08:00

你找一个在线在线 Cron 表达式的工具验证一下不就明白了吗？
比如： http://cron.qqe2.com/

yesterdaysun

2019-09-25 16:23:47 +08:00

就像上面说的, 你必须指定时分秒, 否则就是一秒钟运行一次, 你可以写个测试看一下执行时间就知道了, 网上有些模拟器和 Quartz 的语法不太一样, 而且 Quartz 语法不同版本也不一样, 跑测试最直接了:

```java
@Test
public void test() throws ParseException {
CronTrigger cronTrigger = new CronTrigger("test", "test", "* * * */7 * ?");

Date nextFireTime = new Date();
for (int i = 0; i < 10; i++) {
nextFireTime = cronTrigger.getFireTimeAfter(nextFireTime);
String result = DateFormatUtils.format(nextFireTime, "yyyy-MM-dd HH:mm:ss");
System.out.println(result);
}
}
```