Spring quartz中取得ServletContext

在开发javaWeb定时任务的时候，有些处理要取得应用的相对路径，这就需要用到ServletContext取得到这个路径

解决思路是在web应用启动时，把ServletContext提前注入到Scheduler的Context中

注册一个应用启动的listener

   <listener>
      <listener-class>com.krm.slsint.common.web.listener.StartupListener</listener-class>
   </listener>

在listener中给scheduler加入ServletContext

需要引入：

import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.impl.StdSchedulerFactory;

 public class StartupListener implements ServletContextListener,HttpSessionAttributeListener,HttpSessionListener
  {
      public void contextInitialized(ServletContextEvent event)
      {
          try{
              Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
              scheduler.getContext().put("ServletContextForScheduler", event.getServletContext());
              event.getServletContext().setAttribute(Constants.SCHEDULER_KEY,
                 scheduler);
          catch (SchedulerException e){
                      e.printStackTrace();
              }
          }
      }

     public void contextDestroyed(ServletContextEvent event) {
         Scheduler scheduler = (Scheduler) event.getServletContext().getAttribute(
                 Constants.SCHEDULER_KEY);
         if (scheduler != null) {
             try {
                 scheduler.shutdown(true);
             } catch (SchedulerException e) {
                 if (log.isDebugEnabled()) {
                     log.debug(e.getMessage());
                 }
             }
         }
         servletContext = null;
     }

从JobExecutionContext中读出ServletContext，可以取得中间件路径

 public class BatchMailSendJob extends QuartzJobBean {
     @Override
     protected void executeInternal(JobExecutionContext context) throws JobExecutionException {
         try {
             ServletContext servletContext = (ServletContext) context.getScheduler()
                     .getContext().get("ServletContextForScheduler");
             String dir = servletContext.getRealPath(File.separator);
         } catch (FileNotFoundException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (SchedulerException se) {
             // TODO Auto-generated catch block
             se.printStackTrace();
         }
     }
 }

下面是quartz的配置applicationContext-timertask.xml

<beans>
    <bean name="mailJob"  class="org.springframework.scheduling.quartz.JobDetailBean">
        <property name="jobClass">
            <value>com.krm.slsint.mail.task.BatchMailSendJob</value>
        </property>
        <property name="jobDataAsMap">
            <map>
                <entry key="timeout">
                    <value>5</value>
                </entry>
            </map>
        </property>
    </bean>
    <bean id="mailCronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
        <property name="jobDetail">
            <ref bean="mailJob"/>
        </property>
        <property name="cronExpression">
             <value>0 0/10 9-23 * * ? </value>
        </property>
    </bean>
    <bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
        <property name="triggers">
            <list>
                <ref local="mailCronTrigger"/>
            </list>
        </property>
    </bean>
</beans>