@Override
 public Product get(String id, boolean cascade) throws Exception {
   Product product = productDao.findById(id);
   if (cascade) {
     Article article = articleDao.findById(product.getParentId());
     BeanUtils.copyProperties(product, article);
   }
   return product;
 }
 @Override
 public boolean delete(String id) {
   Product findById = null;
   try {
     findById = productDao.findById(id);
   } catch (Exception e) {
     e.printStackTrace();
   }
   if (findById == null) return false;
   try {
     productDao.delete(findById);
     Article article = articleDao.findById(findById.getParentId());
     articleDao.delete(article);
   } catch (Exception e) {
     e.printStackTrace();
     return false;
   }
   return true;
 }