title: Trigger jenkins build if only a specific file is changed
body: <p>I have my codebase in GIT. There are 5 files in the code base i.e. </p>
  
  <ul>
  <li>File1</li>
  <li>File2</li>
  <li>File3</li>
  <li>File4</li>
  <li>File5</li>
  </ul>
  
  <p>I want to trigger a jenkins build only if File 2 is changed.Please note that, post the build is triggered it should pull the entire codebase. </p>
  
  <p>I tried using poll SCM, but the problem is that the build gets triggered if any of the files in the repository are changed.I want to trigger it only if File 2 changes.</p>
  
  <p>Is it possible?</p>