title: How to extract values of particular instance variable from Map using Java Stream API?
body: <p>I have a HashMap, for each key the value is a User Defined Object. This user defined object has variable of type ArrayList. How can I extract this ArrayList into one List using Java stream API. So, the size of my HashMap is 3. Size of the array list inside each user defined object is   1. Final out should be an arraylist of size 3</p>
  
  <p>My object is</p>
  
  <pre><code>class XYZ{
      List&lt;ABC&gt; list;
  } 
  </code></pre>
  
  <p>My map has values <code>{"1", XYZ_1},{"2",XYZ_2},{"3",XYZ_3}.</code> I want to extract list from each object <code>XYZ_1, XYZ_2,XYZ_3</code> </p>