title: Apache Camel doneFileName with changing name
body: <p>I'm currently creating some route and for one of them I have a problem.
  Usually I have a data file and then a done file which have the same name prefixed by &quot;ACK&quot; and this works perfectly with camel and the doneFileName option.</p>
  <p>But for one of my route I have to work with a different situation, I still receive two files but they have the same typology, it's like: <code>MyFILE-{{timestamp}}</code>. The data file contains the data, and the done file contains just &quot;done&quot;.</p>
  <p>So I need something to check the content of the file, and if it's juste &quot;done&quot; then process the other file.</p>
  <p>Is there a way to handle this with camel?</p>