title: collections.sort to define the sort order on two elements?
body: <p>I am writing my own comparator class called <code>PercentComparator</code> and called the sort as follows</p>
  
  <pre><code>Collections.sort(engineList, new PercentageComparator());
  </code></pre>
  
  <p>where <code>engineList</code> is List of objects, where each object has percent complete values, and above sort functionality is working fine. </p>
  
  <p>Now customer is asking to add another order by element by its product type along with percent. Can we do sort order by two elements of objects?</p>