title: JSR303's primitive and iterable primitive validator
body: <p>Is it somehow possible to implement a custom validator which handles both <code>T</code> and <code>Iterable&lt;T&gt;</code> objects, where <code>T</code> is either primitive type or object?
  The goal is to implement only a single ConstraintValidator object instead of two: <code>*ConstraintValidator</code> and <code>*ListConstraintValidator</code>
  Thank you in advance</p>