title: MapStruct object inheritance mapping
body: <p>I have a given scenario like below</p>
  <pre><code>&gt; class Curve {
        private List&lt;Point&gt; points = new ArrayList&lt;&gt;();
    }
  
  &gt; class Points {
        private Axis xAxis;
        private Axis yAxis;
        private Axis zAxis;
     }
  
  &gt; abstract class Axis {}
  
  &gt; class XAxis extends Axis {}
  &gt; class YAxis extends Axis {}
  &gt; class ZAxis extends Axis {}
  </code></pre>
  <p>I am creating a Mapper for Curve class like :</p>
  <pre><code>@Mapper
  public interface CurveMapper {
  
   CurveMapper INSTANCE = Mappers.getMappers(CurveMapper.class);
   
   com.entity.Curve map(com.dto.Curve dtoCurve);    
  
  }
  </code></pre>
  <blockquote>
  <p>The build fails asking for concrete class/Object factory for <code>Axis</code>
  class.</p>
  </blockquote>
  <p>I can add the <code>objectFactory</code> for Axis class but how can I map all 3 different concrete classes by single <code>objectFactory</code>.</p>