title: Sorting arraylist of objects based on the date time
body: <p>I have two arraylists that consist of the datetime objects and merging both the list using.</p>
  
  <pre><code>list1.addAll(list2);
  </code></pre>
  
  <p>I want to now sort this arraylist on the order of the date time object that the arraylist consists of. Can anyone guide me how to sort this arraylist.</p>