public synchronized Product addProduct(Product product) {
		if (product != null) {
			try {
				listProduct.put(product);
				logger.info("Product: " + product.getName() + " Code: "
						+ product.getCode() + " ,successfully added!");
			} catch (InterruptedException e) {
				e.getMessage();
			} catch (NullPointerException e) {
				e.getMessage();
			}
			return product;

		} else {
			return null;
		}
	}