class ProductCartService extends WebService {

   @PreAuthorize("hasRole('ROLE_DOWNLOAD')")
   @Transactional(propagation = Propagation.REQUIRED)
   public void clearCart(String uuid) throws UserNotExistingException
   {
      ProductCart cart = getCartOfUser(uuid);
      if ((cart != null) && (cart.getProducts() != null))
      {
         cart.getProducts().clear();
         productCartDao.update(cart);
      }
   }

}