quartz启动后不执行

按照老师的方式 配置好了配置文件但是启动后不执行 是什么原因

<bean id="SimpleTrigger" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">

<property name="targetObject" ref="timing" />

<property name="targetMethod" value="run" />

<property name="concurrent" value="false"/>

</bean> 

 <bean id="myCronTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">

   <property name="jobDetail"  ref="SimpleTrigger"/>

   <property name="cronExpression"  value="0/5 * * ? * *"/>

</bean> 

<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">

   <property name="triggers">

       <list>

           <ref bean="myCronTrigger"/>

       </list>

   </property>

</bean>

@Component("timing")

public class Timing {

public void run() {

Date date = new Date();

SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

System.out.println("MyBean Executes!" + sf.format(date));

}

}