Quartz实现固定执行次数

Quartz实现固定执行次数 
虽然上一讲中说明,在实际应用中很少用到Quartz实现固定执行次数，但是我就是那个钻牛角尖的人.废话不多，代码如下: 

实现思路: 
1. 在上一讲中说明Quartz的JobDetail可以是无状态的，也可以是有状态的。Trigger无状态的，所以只能使用JobDetail有状态的子接口StatefulJob.Job代码如下: 

 package test.quartz.spring;

 import java.util.Date;

 import org.quartz.Job;
 import org.quartz.JobDataMap;
 import org.quartz.JobExecutionContext;
 import org.quartz.JobExecutionException;
 import org.quartz.StatefulJob;

 public class TJob implements StatefulJob {

     /**
      * 不用挣扎了，Quartz都是无状态的，他不知道执行了几次。
      * 如果想要记录状态就需要持久化到数据库.
      */
     public void execute(JobExecutionContext cntxt) throws JobExecutionException {

         JobDataMap jobDataMap = cntxt.getJobDetail().getJobDataMap();
         Integer count = (Integer) jobDataMap.get("count");
         if(count==null){
             count=0;
         }
         count++;
          System.out.println("杨春龙,太帅了");
          System.out.println("不是我说的");
          System.out.println( " Generating report -  "
                 +  count
                 +  "-"
                 +   new  Date());
          jobDataMap.put("count", count);
          cntxt.getJobDetail().setJobDataMap(jobDataMap);


     }

 }

根据ApI描述，如果是有状态的Job，所有的Job都共享jobDataMap,所有把执行次数记录下来.虽然我记录了执行次数，但是因为Job是一个Thread，由ThreadPool来维持,那么如何监视Job的执行情况，在看源码中，发现有一个Listener，可以监听进程的执行，代码如下: 

 package test.quartz.spring;

 import org.quartz.CronTrigger;
 import org.quartz.JobExecutionContext;
 import org.quartz.SchedulerException;
 import org.quartz.Trigger;
 import org.quartz.listeners.TriggerListenerSupport;

 public class TriggerListener extends TriggerListenerSupport {

     private String name;

     private Integer count;
     public void setName(String name)
     {
         this.name=name;
     }

     public String getName() {
         // TODO Auto-generated method stub
         return this.name;
     }


     public Integer getCount() {
         return count;
     }

     public void setCount(Integer count) {
         this.count = count;
     }

     @Override
     public void triggerComplete(Trigger trigger, JobExecutionContext context,
             int triggerInstructionCode) {
         System.out.println("Trigger :"+trigger.getGroup()+"."+trigger.getName()+" completed with code:"+triggerInstructionCode);
         Integer current = (Integer) context.getJobDetail().getJobDataMap().get("count");
         System.out.println("调用次数:"+current);
         if(current == count){
             try {
                 context.getScheduler().shutdown();
             } catch (SchedulerException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
         super.triggerComplete(trigger, context, triggerInstructionCode);
     }



 }

在Job的执行中设置执行次数，在监听器中得到执行次数，当执行次数到达count的时候退出执行. 
JobQuartz.xml配置如下 

 "1.0" encoding="UTF-8"?>
 "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">




     "job" class="test.quartz.spring.TJob">
     "triggerListener" class="test.quartz.spring.TriggerListener">
         "name">
             triggerListener

         "count">
             3



     "jobtask" class="org.springframework.scheduling.quartz.JobDetailBean">
         "jobClass">
             test.quartz.spring.TJob




     "cron" class = "org.springframework.scheduling.quartz.CronTriggerBean">

         "jobDetail">
             "jobtask"/>

         "triggerListenerNames">

                triggerListener


         "cronExpression">
             0/10 * * * * ?



     "no" class = "org.springframework.scheduling.quartz.SchedulerFactoryBean">
         "triggers">

                 "cron"/>



         "triggerListeners">

                 "triggerListener"/>

在SchedulerFactoryBean中配置监听器列表，在CronTriggerBean配置监听器名称，这样这个监听器就可以监听这个Trigger了，当执行了3次后自动退出 
测试代码如下: 

 package test.quartz.spring;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 public class TestSpring {

     /**
      * @param args
      */
     public static void main(String[] args) {
         System.out.println("测试开始");
         ApplicationContext ctx = new ClassPathXmlApplicationContext("JobQuartz.xml");
         System.out.println("测试结束");

     }

 }

测试输出如下: 
测试开始 

 2010-09-27 09:33:39,640 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - @3e86d0: display name [org.springframework.context.support.ClassPathXmlApplicationContext@3e86d0]; startup date [Mon Sep 27 09:33:39 CST 2010]; root of context hierarchy>
 2010-09-27 09:33:39,718 INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - class path resource [JobQuartz.xml]>
 2010-09-27 09:33:39,781 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - for application context [org.springframework.context.support.ClassPathXmlApplicationContext@3e86d0]: org.springframework.beans.factory.support.DefaultListableBeanFactory@197a37c>
 2010-09-27 09:33:39,812 INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - @197a37c: defining beans [job,triggerListener,jobtask,cron,org.springframework.scheduling.quartz.SchedulerFactoryBean#0]; root of factory hierarchy>
 2010-09-27 09:33:39,953 INFO [org.quartz.core.SchedulerSignalerImpl] - class org.quartz.core.SchedulerSignalerImpl>
 2010-09-27 09:33:39,953 INFO [org.quartz.core.QuartzScheduler] - 1.8.3 created.>
 2010-09-27 09:33:39,953 INFO [org.quartz.simpl.RAMJobStore] -
 2010-09-27 09:33:39,953 INFO [org.quartz.core.QuartzScheduler] - 8.3) 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' with instanceId 'NON_CLUSTERED'
   Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
   NOT STARTED.
   Currently in standby mode.
   Number of jobs executed: 0
   Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads.
   Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered.
 >
 2010-09-27 09:33:39,953 INFO [org.quartz.impl.StdSchedulerFactory] - 'org.springframework.scheduling.quartz.SchedulerFactoryBean#0' initialized from an externally provided properties instance.>
 2010-09-27 09:33:39,953 INFO [org.quartz.impl.StdSchedulerFactory] - 1.8.3>
 2010-09-27 09:33:39,953 INFO [org.quartz.core.QuartzScheduler] - @1b09468>
 2010-09-27 09:33:39,953 INFO [org.springframework.scheduling.quartz.SchedulerFactoryBean] -
 2010-09-27 09:33:39,953 INFO [org.quartz.core.QuartzScheduler] -
 测试结束
 杨春龙,太帅了
 不是我说的
  Generating report -  1-Mon Sep 27 09:33:40 CST 2010
 Trigger :DEFAULT.cron completed with code:0
 调用次数:1
 杨春龙,太帅了
 不是我说的
  Generating report -  2-Mon Sep 27 09:33:50 CST 2010
 Trigger :DEFAULT.cron completed with code:0
 调用次数:2
 杨春龙,太帅了
 不是我说的
  Generating report -  3-Mon Sep 27 09:34:00 CST 2010
 Trigger :DEFAULT.cron completed with code:0
 调用次数:3
 2010-09-27 09:34:00,000 INFO [org.quartz.core.QuartzScheduler] -
 2010-09-27 09:34:00,000 INFO [org.quartz.core.QuartzScheduler] -
 2010-09-27 09:34:00,000 INFO [org.quartz.core.QuartzScheduler] -