Java Web应用中的任务调度

public void init(ActionServlet actionServlet,
                 ModuleConfig moduleConfig) {

  System.out.println("Initializing Scheduler PlugIn for Jobs!");
  // Retrieve the ServletContext
// 获取ServletContext
  ServletContext ctx = actionServlet.getServletContext();
  // The Quartz Scheduler
  // Quartz Scheduler对象
  Scheduler scheduler = null;

  // Retrieve the factory from the ServletContext.
  // It will be put there by the Quartz Servlet
  // 从ServletContext取得由Quartz Servlet放置在此的factory对象。
  StdSchedulerFactory factory =  (StdSchedulerFactory)
      ctx.getAttribute(QuartzInitializerServlet.QUARTZ_FACTORY_KEY);
   
  try{
        // Retrieve the scheduler from the factory
        // 从factory取得scheduler
        scheduler = factory.getScheduler();

        // Start the scheduler in case, it isn't started yet
        // 如果scheduler尚未启动，则启动它
        if (m_startOnLoad != null &&
            m_startOnLoad.equals(Boolean.TRUE.toString())){
            System.out.println("Scheduler Will start in " +
            m_startupDelayString + " milliseconds!");
            //wait the specified amount of time before
            // starting the process.
            // 在启动之前等待指定长度的时间
            Thread delayedScheduler =
                new Thread(new DelayedSchedulerStarted (
                                   scheduler, m_startupDelay));
            //give the scheduler a name. All good code needs a name
            //给任务调度器命名。好的代码总该有名字！
            delayedScheduler.setName("Delayed_Scheduler");
            //Start out scheduler
            //启动任务调度器
            delayedScheduler.start();
        }
  } catch (Exception e){
     e.printStackTrace();
  }
    sm_scheduler = scheduler;
}

  <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>1</load-on-startup>
  <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>false</param-value>
    </init-param>

 </servlet>

import org.quartz.JobDataMap;
import org.quartz.JobDetail;
import org.quartz.JobExecutionContext;

//extend the proper Quartz class
//继承适当的Quartz类
public class HelloWorld extends Job {

//override the execute method
//覆盖execute方法
    public void execute(JobExecutionContext context) {

// Every job has it's own job detail
//每个Job都有独立的JobDetail
    JobDetail jobDetail = context.getJobDetail();
// The name is defined in the job definition
//name在Job定义中指定
    String jobName = jobDetail.getName();
//Every job has a Job Data map for storing extra information
//每个Job都有一个Job Data map来存放额外的信息
    JobDataMap dataMap = jobDetail.getJobDataMap();
      
       System.out.println("Hello World!!!");
   }
 }

每5秒执行一次的触发器
/*  *
 * 方法一：makeSecondlyTrigger
 * 注意以下代码将创建一个立即启动的触发器。要控制启动时间，使用
 * trigger.setStartTime(Date)方法。
 */
Trigger trigger = TriggerUtils.makeSecondlyTrigger(5);
trigger.setName("MyFiveSecondTrigger");
trigger.setGroup("MyTriggerGroup");

 /*
 *
 * 方法二：设置SimpleTrigger的重复次数和间隔时间。
 * 注意以下代码将创建一个立即启动的触发器。要控制启动时间，使用
 * trigger.setStartTime(Date)方法。
 */
Trigger trigger = new SimpleTrigger("trigger1", "group1");
trigger.setRepeatCount(SimpleTrigger.REPEAT_INDEFINITELY);
trigger.setRepeatInterval(5000L); // milliseconds