计划任务的顺序执行[Quartz Scheduler v.2.1.6]

使用Quartz做计划任务时，默认情况下，当前任务总会执行，无论前一个任务是否结束。从如下日志可以看出，job被并发执行，无视前面任务是否结束。

13:14:04,095 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:14:04,095 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - n=1
13:14:04,095 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 executing at Sun Apr 07 13:14:04 CST 2013
13:14:06,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:14:06,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - n=2
13:14:06,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - group1.job1 executing at Sun Apr 07 13:14:06 CST 2013
13:14:07,095 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 done.
13:14:08,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:14:08,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-3 - n=3
13:14:08,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-3 - group1.job1 executing at Sun Apr 07 13:14:08 CST 2013
13:14:09,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - group1.job1 done.

因此，如果采用默认条件，需要考虑并发执行的逻辑问题，否则需要设置为顺序执行。

第一种办法是为自定义的job加上@org.quartz.DisallowConcurrentExecution注解，告诉quartz不允许并发执行job任务。这个办法粗粒度地解决了并发问题，缺少灵活度，但很简单，也很简洁。

13:20:04,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:20:04,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - n=1
13:20:04,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 executing at Sun Apr 07 13:20:04 CST 2013
13:20:07,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 done.
13:20:07,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:20:07,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - n=2
13:20:07,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - group1.job1 executing at Sun Apr 07 13:20:07 CST 2013
13:20:10,017 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - group1.job1 done.

第二种办法是在job的执行方法体内编写处理代码

13:24:18,236 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:24:18,236 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - n=1
13:24:18,236 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 executing at Sun Apr 07 13:24:18 CST 2013
13:24:20,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:24:20,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-2 - <
13:24:21,236 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-1 - group1.job1 done.
13:24:22,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_QuartzSchedulerThread - new a simple job
13:24:22,001 INFO
[creative.air.schedule.quartz.SimpleJob] DefaultQuartzScheduler_Worker-3 - n=2

相关测试代码：

测试类

job生产类

job类

最后需要注意的是，quartz的发展出现了分支，目前存在并行版本

spring与quartz1集成更友好