how to properly handle case when theres no records in the db table?

Optional<Customer> customer=customerRepository.findById(Long.valueOf(paymentInformationRequest.getClientId()));
        if (customer.isEmpty()) {
            log.info("BGWService.createPaymentInformation. no customer with id: {}", paymentInformationRequest.getClientId());
            throw new IllegalArgumentException("BGWService.createPaymentInformation. no customer with id:"+paymentInformationRequest.getClientId());
        }