title: Get all Fields of class hierarchy
body: <p>I have classes:</p>
  
  <pre><code>ClassA{
   public String filedA;
  }
  
  ClassB extends ClassA{
   public String filedB;
  }
  
  ClassC extends ClassB{
   public String filedC;
  }
  </code></pre>
  
  <p>Then I create object:</p>
  
  <pre><code>ClassC c=new ClassC();
  c.fieldC="TestC";
  c.fieldA="TestA";
  c.fieldB="TestB";
  </code></pre>
  
  <p>After I try get all fields, I call</p>
  
  <pre><code>Field[] fields=c.getClass().getDeclaredFields();
  </code></pre>
  
  <p>But I get array with only one item</p>
  
  <pre><code>fields[fieldC]
  </code></pre>
  
  <p>How to get all fields from all classes include extends?</p>