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一個cron表達式有至少6個（也可能是7個）由空格分隔的時間元素。從左至右，這些元素的定義如下：
1．秒（0–59）
2．分鐘（0–59）
3．小時（0–23）
4．月份中的日期（1–31）
5．月份（1–12或JAN–DEC）
6．星期中的日期（1–7或SUN–SAT）
7．年份（1970–2099）
每一個元素都可以顯式地規定一個值（如6），一個區間（如9-12），一個列表（如9，11，13）或一個通配符（如*）。“月份中的日期”和“星期中的日期”這兩個元素是互斥的，因此應該通過設置一個問號（？）來表明你不想設置的那個字段。表中顯示了一些cron表達式的例子和它們的意義：
Cron 表達式包括以下 7 個字段：
一些cron表達式的例子
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表 達 式
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意 義
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0 0 10,14,16 * * ?
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每天上午10點，下午2點和下午4點
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0 0,15,30,45 * 1-10 * ?
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每月前10天每隔15分鐘
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30 0 0 1 1 ? 2012
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在2012年1月1日午夜過30秒時
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0 0 8-5 ? * MON-FRI
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每個工作日的工作時間
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對于cronReportTrigger，我們設置cronExpression為0 0 6 * * ?可以把它讀作“在任何月份任何日期（不管是星期幾）的6時0分0秒執行觸發器。換句話說，這個觸發器會在每天早晨6:00執行。
使用CronTriggerBean完全能夠滿足課程主任的期望了。現在剩下要做的只是啟動這個工作了。
- 秒
- 分
- 小時
- 月內日期
- 月
- 周內日期
- 年（可選字段）
特殊字符
Cron 觸發器利用一系列特殊字符，如下所示：
- 反斜線（/）字符表示增量值。例如，在秒字段中“5/15”代表從第 5 秒開始，每 15 秒一次。
- 問號（?）字符和字母 L 字符只有在月內日期和周內日期字段中可用。問號表示這個字段不包含具體值。所以，如果指定月內日期，可以在周內日期字段中插入“?”，表示周內日期值無關緊要。字母 L 字符是 last 的縮寫。放在月內日期字段中，表示安排在當月最后一天執行。在周內日期字段中，如果“L”單獨存在，就等于“7”，否則代表當月內周內日期的最后一個實例。所以“0L”表示安排在當月的最后一個星期日執行。
- 在月內日期字段中的字母（W）字符把執行安排在最靠近指定值的工作日。把“1W”放在月內日期字段中，表示把執行安排在當月的第一個工作日內。
- 井號（#）字符為給定月份指定具體的工作日實例。把“MON#2”放在周內日期字段中，表示把任務安排在當月的第二個星期一。
- 星號（*）字符是通配字符，表示該字段可以接受任何可能的值。
SimpleJob.java
/*
* Copyright 2005 OpenSymphony
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy
* of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
*/
package org.quartz.examples.example3;
import java.util.Date;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
/**
* <p>
* This is just a simple job that gets fired off many times by example 1
* </p>
*
* @author Bill Kratzer
*/
public class SimpleJob implements Job {
private static Log _log = LogFactory.getLog(SimpleJob.class);
/**
* Quartz requires a public empty constructor so that the
* scheduler can instantiate the class whenever it needs.
*/
public SimpleJob() {
}
/**
* <p>
* Called by the <code>{@link org.quartz.Scheduler}</code> when a
* <code>{@link org.quartz.Trigger}</code> fires that is associated with
* the <code>Job</code>.
* </p>
*
* @throws JobExecutionException
* if there is an exception while executing the job.
*/
public void execute(JobExecutionContext context)
throws JobExecutionException {
// This job simply prints out its job name and the
// date and time that it is running
String jobName = context.getJobDetail().getFullName();
_log.info("SimpleJob says: " + jobName + " executing at " + new Date());
System.out.println(context.getTrigger().getFullName());
}
}
CronTriggerExample.java
/*
* Copyright 2005 OpenSymphony
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy
* of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
*/
package org.quartz.examples.example3;
import java.util.Date;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.CronTrigger;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerFactory;
import org.quartz.SchedulerMetaData;
import org.quartz.impl.StdSchedulerFactory;
/**
* This Example will demonstrate all of the basics of scheduling capabilities of
* Quartz using Cron Triggers.
*
* @author Bill Kratzer
*/
public class CronTriggerExample {
public void run() throws Exception {
Log log = LogFactory.getLog(CronTriggerExample.class);
log.info("------- Initializing -------------------");
// First we must get a reference to a scheduler
SchedulerFactory sf = new StdSchedulerFactory();
Scheduler sched = sf.getScheduler();
log.info("------- Initialization Complete --------");
log.info("------- Scheduling Jobs ----------------");
// jobs can be scheduled before sched.start() has been called
// job 1 will run every 20 seconds
JobDetail job = new JobDetail("job1", "group1", SimpleJob.class);
CronTrigger trigger = new CronTrigger("trigger1", "group1", "job1",
"group1", "0/20 * * * * ?");
sched.addJob(job, true);
Date ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 2 will run every other minute (at 15 seconds past the minute)
job = new JobDetail("job2", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger2", "group1", "job2", "group1",
"15 0/2 * * * ?");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 3 will run every other minute but only between 8am and 5pm
job = new JobDetail("job3", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger3", "group1", "job3", "group1",
"0 0/2 8-17 * * ?");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 4 will run every three minutes but only between 5pm and 11pm
job = new JobDetail("job4", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger4", "group1", "job4", "group1",
"0 0/3 17-23 * * ?");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 5 will run at 10am on the 1st and 15th days of the month
job = new JobDetail("job5", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger5", "group1", "job5", "group1",
"0 0 10am 1,15 * ?");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 6 will run every 30 seconds but only on Weekdays (Monday through
// Friday)
job = new JobDetail("job6", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger6", "group1", "job6", "group1",
"0,30 * * ? * MON-FRI");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
// job 7 will run every 30 seconds but only on Weekends (Saturday and
// Sunday)
job = new JobDetail("job7", "group1", SimpleJob.class);
trigger = new CronTrigger("trigger7", "group1", "job7", "group1",
"0,30 * * ? * SAT,SUN");
sched.addJob(job, true);
ft = sched.scheduleJob(trigger);
log.info(job.getFullName() + " has been scheduled to run at: " + ft
+ " and repeat based on expression: "
+ trigger.getCronExpression());
log.info("------- Starting Scheduler ----------------");
// All of the jobs have been added to the scheduler, but none of the
// jobs
// will run until the scheduler has been started
sched.start();
log.info("------- Started Scheduler -----------------");
log.info("------- Waiting five minutes ------------");
try {
// wait five minutes to show jobs
Thread.sleep(300L * 1000L);
// executing
} catch (Exception e) {
}
log.info("------- Shutting Down ---------------------");
sched.shutdown(true);
log.info("------- Shutdown Complete -----------------");
SchedulerMetaData metaData = sched.getMetaData();
log.info("Executed " + metaData.numJobsExecuted() + " jobs.");
}
public static void main(String[] args) throws Exception {
CronTriggerExample example = new CronTriggerExample();
example.run();
}
}
運行結果：
2008-12-22 21:25:22 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Initializing -------------------
2008-12-22 21:25:23 org.quartz.simpl.SimpleThreadPool initialize
信息: Job execution threads will use class loader of thread: main
2008-12-22 21:25:23 org.quartz.core.SchedulerSignalerImpl <init>
信息: Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl
2008-12-22 21:25:23 org.quartz.core.QuartzScheduler <init>
信息: Quartz Scheduler v.1.6.4 created.
2008-12-22 21:25:23 org.quartz.simpl.RAMJobStore initialize
信息: RAMJobStore initialized.
2008-12-22 21:25:23 org.quartz.impl.StdSchedulerFactory instantiate
信息: Quartz scheduler 'DefaultQuartzScheduler' initialized from default resource file in Quartz package: 'quartz.properties'
2008-12-22 21:25:23 org.quartz.impl.StdSchedulerFactory instantiate
信息: Quartz scheduler version: 1.6.4
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Initialization Complete --------
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Scheduling Jobs ----------------
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job1 has been scheduled to run at: Mon Dec 22 21:25:40 CST 2008 and repeat based on expression: 0/20 * * * * ?
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job2 has been scheduled to run at: Mon Dec 22 21:26:15 CST 2008 and repeat based on expression: 15 0/2 * * * ?
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job3 has been scheduled to run at: Tue Dec 23 08:00:00 CST 2008 and repeat based on expression: 0 0/2 8-17 * * ?
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job4 has been scheduled to run at: Mon Dec 22 21:27:00 CST 2008 and repeat based on expression: 0 0/3 17-23 * * ?
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job5 has been scheduled to run at: Thu Jan 01 10:00:00 CST 2009 and repeat based on expression: 0 0 10AM 1,15 * ?
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job6 has been scheduled to run at: Mon Dec 22 21:25:30 CST 2008 and repeat based on expression: 0,30 * * ? * MON-FRI
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: group1.job7 has been scheduled to run at: Sat Dec 27 00:00:00 CST 2008 and repeat based on expression: 0,30 * * ? * SAT,SUN
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Starting Scheduler ----------------
2008-12-22 21:25:23 org.quartz.core.QuartzScheduler start
信息: Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED started.
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Started Scheduler -----------------
2008-12-22 21:25:23 org.quartz.examples.example3.CronTriggerExample run
信息: ------- Waiting five minutes... ------------
group1.trigger6
2008-12-22 21:25:30 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job6 executing at Mon Dec 22 21:25:30 CST 2008
group1.trigger1
2008-12-22 21:25:40 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job1 executing at Mon Dec 22 21:25:40 CST 2008
group1.trigger1
2008-12-22 21:26:00 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job1 executing at Mon Dec 22 21:26:00 CST 2008
group1.trigger6
2008-12-22 21:26:00 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job6 executing at Mon Dec 22 21:26:00 CST 2008
group1.trigger2
2008-12-22 21:26:15 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job2 executing at Mon Dec 22 21:26:15 CST 2008
group1.trigger1
2008-12-22 21:26:20 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job1 executing at Mon Dec 22 21:26:20 CST 2008
group1.trigger6
2008-12-22 21:26:30 org.quartz.examples.example3.SimpleJob execute
信息: SimpleJob says: group1.job6 executing at Mon Dec 22 21:26:30 CST 2008
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