quartz 动态更改执行时间

说明:Quartz + Servlet, 参考国外著名站点的文章：http://stackoverflow.com/questions/12208309/need-to-set-the-quartz-cron-expression-dynamically  看域名，大家就知道了吧。

 

1、简单编写一个 quartz 例子

package cn.demo.quartz;

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

public class CountJob implements Job
{

    public void execute(JobExecutionContext arg0) throws JobExecutionException
    {
        System.out.println("5s execute");
        
    }

}

2、在 src 目录下，添加2个配置文件

quartz_job.xml

?

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<?xml version="1.0" encoding="UTF-8"?> <job-scheduling-data     xmlns="http://www.quartz-scheduler.org/xml/JobSchedulingData"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation="http://www.quartz-scheduler.org/xml/JobSchedulingData                               http://www.quartz-scheduler.org/xml/job_scheduling_data_2_0.xsd"     version="2.0">       <pre-processing-commands>         <delete-jobs-in-group>*</delete-jobs-in-group>         <!-- clear all jobs in scheduler -->         <delete-triggers-in-group>*</delete-triggers-in-group>         <!-- clear all triggers in scheduler -->     </pre-processing-commands>       <processing-directives>         <!-- if there are any jobs/trigger in scheduler of same name (as in this file), overwrite them -->         <overwrite-existing-data>true</overwrite-existing-data>         <!-- if there are any jobs/trigger in scheduler of same name (as in this file), and over-write is false, ignore them rather then generating an error -->         <ignore-duplicates>false</ignore-duplicates>     </processing-directives>         <schedule>         <job>             <name>job1</name>             <job-class>cn.demo.quartz.CountJob</job-class>         </job>         <trigger>             <cron>                 <name>trigger_name1</name>                 <group>trigger_group1</group>                 <job-name>job1</job-name>                 <cron-expression>0/5 * * * * ?</cron-expression>             </cron>         </trigger>     </schedule>                   </job-scheduling-data>

还有 quartz.properties

?

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org.quartz.scheduler.instanceName=MyQuartzScheduler  org.quartz.scheduler.rmi.export=false  org.quartz.scheduler.rmi.proxy=false  org.quartz.scheduler.wrapJobExecutionInUserTransaction=false  org.quartz.threadPool.class=org.quartz.simpl.SimpleThreadPool  org.quartz.threadPool.threadCount=10  org.quartz.threadPool.threadPriority=5  org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread=true  org.quartz.jobStore.misfireThreshold=60000  org.quartz.jobStore.class=org.quartz.simpl.RAMJobStore  org.quartz.plugin.jobInitializer.class=org.quartz.plugins.xml.XMLSchedulingDataProcessorPlugin  #job and trigger configuration file  org.quartz.plugin.jobInitializer.fileNames=quartz_job.xml

 

3、添加一个 Servlet, ChangeTimeServlet

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package cn.demo.servlet;   import java.io.IOException;   import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;   import org.quartz.CronExpression; import org.quartz.CronTrigger; import org.quartz.Scheduler; import org.quartz.SchedulerFactory; import org.quartz.impl.StdSchedulerFactory;   public class ChangeTimeServlet extends HttpServlet {       /**      *      */     private static final long serialVersionUID = 4586397924078936339L;       public void doGet(HttpServletRequest request, HttpServletResponse response)             throws ServletException, IOException     {           this.doPost(request, response);     }       public void doPost(HttpServletRequest request, HttpServletResponse response)             throws ServletException, IOException     {         try         {             SchedulerFactory factory = new StdSchedulerFactory();               Scheduler scheduler = factory.getScheduler();                            CronTrigger cronTrigger = (CronTrigger) scheduler.getTrigger("trigger_name1", "trigger_group1");                       CronTrigger newTriggerIns = new CronTrigger();                           newTriggerIns.setJobName(cronTrigger.getJobName());             newTriggerIns.setName("abc");             newTriggerIns.setCronExpression(new CronExpression("0/20 * * * * ?"));                           scheduler.rescheduleJob("trigger_name1", "trigger_group1", newTriggerIns);         } catch (Exception e)         {             e.printStackTrace();         }     }   }

4、web.xml 配置文件添加

<!-- quartz start -->
    <servlet>
        <servlet-name>QuartzInitializer</servlet-name>
        <display-name>Quartz Initializer Servlet</display-name>
        <servlet-class>
            org.quartz.ee.servlet.QuartzInitializerServlet
        </servlet-class>
        <load-on-startup>3</load-on-startup>
        <init-param>
            <param-name>config-file</param-name>
            <param-value>/quartz.properties</param-value>
        </init-param>
        <init-param>
            <param-name>shutdown-on-unload</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>start-scheduler-on-load</param-name>
            <param-value>true</param-value>
        </init-param>
    </servlet>

    <!-- quartz end -->

    <servlet>
        <servlet-name>ChangeTimeServlet</servlet-name>
        <servlet-class>cn.demo.servlet.ChangeTimeServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>ChangeTimeServlet</servlet-name>
        <url-pattern>/change</url-pattern>
    </servlet-mapping>

 

5、启动 tomcat

每间隔 5s，控制台会打印语句

System.out.println("5s execute");

访问servlet http://localhost:8660/change

这时候，会间隔 20s 打印语句。

 

感谢 http://stackoverflow.com，帮我解决了无数次的问题。现在也越来越佩服自己了，太会模仿了。