title: How to change cron expression in CronTrigger (quartz 2.2, spring 4.1)
body: <p>I'm a bit stuck migrating to latest quartz 2.2 and spring 4.1... Here's a cron trigger, I omit the job and other fluff for clarity:</p>
  
  <pre><code>...
         &lt;bean id="timeSyncTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean"&gt;
           &lt;property name="jobDetail" ref="timeSyncJob"/&gt;
           &lt;property name="startDelay" value="10000"/&gt;
           &lt;property name="cronExpression" value="0 0 1 * * ? *"/&gt;
         &lt;/bean&gt;
  ...
  </code></pre>
  
  <p>Now, I need to change its <em>cronExpression</em> at run time, and it's not as simple as I thought. I can't reference the bean and change the property because its a factory giving <em>CronTrigger</em> interface which in turn doesn't have <em>setCronExpression</em> method any longer, it has become immutable. Before I could simply fish out a trigger from the context and set its new cron expression. It worked very well for many years, until the upgrade become unavoidable.</p>
  
  <p>So, how do we accomplish this simple task today? Totally lost in documentations and versions.. Thanks in advance!</p>