spring email scheduler sending out too many emails
<p>I've attempted to send out an email using the spring scheduler so that it will send out an email twice a day at 9AM and 4PM, but the issue that I'm running into is that the scheduler will send out 4 emails instead of 1 when it executes the job. Here's what I have at the moment in my spring configuration file :</p>

<pre><code>    &lt;!-- Email Notification Job --&gt;
&lt;bean id="emailJobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean"&gt;
    &lt;property name="name" value="emailNotification" /&gt;
    &lt;property name="group" value="notification" /&gt;
    &lt;property name="targetObject" ref="notificationService" /&gt;
    &lt;property name="targetMethod" value="createNotification" /&gt;
    &lt;property name="concurrent" value="false" /&gt;
&lt;/bean&gt;
    &lt;!-- Email job description --&gt;
&lt;bean id="emailNotification" class="org.springframework.scheduling.quartz.CronTriggerBean"&gt;
    &lt;property name="cronExpression" value="0 0 9,16 * * ?" /&gt;   &lt;!-- Starts at 9am and 4pm everyday --&gt;
    &lt;property name="jobDetail" ref="emailJobDetail" /&gt;
&lt;/bean&gt;
     &lt;!-- Scheduler --&gt;
&lt;bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean"&gt;
    &lt;property name="triggers"&gt;
        &lt;list&gt;
            &lt;ref bean="emailNotification"/&gt;
        &lt;/list&gt;
    &lt;/property&gt;
&lt;/bean&gt;
</code></pre>

<p>So this will execute the createNotification method in the spring service 'notificationService' which will send out the email to the user. Does anyone have a better understanding of this issue?</p>
