code: public static boolean hasInterface(Class<?> has, Class<?> in)
      {
          if (has.equals(in))
          {
              return true;
          }
          boolean match = false;
          for (Class<?> intrface : in.getInterfaces())
          {
              if (intrface.getInterfaces().length > 0)
              {
                  match = hasInterface(has, intrface);
              }
              else
              {
                  match = intrface.equals(has);
              }
  
              if (match)
              {
                  return true;
              }
          }
          return false;
      }
docs: Checks for interface "has" in class "in".
  
  @param has
  the has
  @param in
  the in
  
  @return true, if exists?