title: How to receive difference of maps in java?
body: <p>I have two maps:</p>
  
  <pre><code>Map&lt;String, Object&gt; map1;
  Map&lt;String, Object&gt; map2;
  </code></pre>
  
  <p>I need to receive difference between these maps. Does exist may be apache utils how to receive this difference?
  For now seems need take entry set of each map and found diff1 = set1 - set2 and diff2 = set2- set1.
  After create summary map =diff1 + diff2
  It looks very awkwardly. Does exist another way?
  Thanks.</p>