Stripe Cart to Order

Stripe is a cloud-based service that enables businesses and individuals to receive payments over the internet and offers both client-side libraries (JavaScript and native mobile) and server-side libraries (Java, Ruby, Node.js, etc.).

Stripe provides a layer of abstraction that reduces the complexity of receiving payments. As a result, we don't need to deal with credit card details directly – instead, we deal with a token symbolizing an authorization to paymentintent, intent confirm and capture.

Simple Spring Boot project that allows users browse prodcuts, add to cart, input customer info and a credit card and later will charge the card for a certain amount using the Stripe API for Java.

Dependencies

To make use of the Stripe API for Java in the project, we add the corresponding dependency to our pom.xml:

		<dependency>
			<groupId>com.stripe</groupId>
			<artifactId>stripe-java</artifactId>
			<version>20.128.0</version>
		</dependency>

General Flow

1. User Clicks on Product List link on top menu
   • Pre configured products are fetched from Stripe with Products API (https://stripe.com/docs/api/products)
2. Add Product to cart
3. Click on my cart
4. Add customer informtion
5. Add credit card information
   • Card input fileds are rendered with the help of Stripe html elements
   • Send card details to Stripe and generate the token. for more of token (https://stripe.com/docs/js/tokens_sources/create_token)
6. Submit the Cart for Order
7. Backend does the following steps
   • Create Customer information on Stripe
   • Create payment intent for cart amount with token (generated at step 5) and customer id
   • Covert Cart to Order
   • Capture the Payment Intent
8. Display Payment Intent Id along with Order Id on Order Confirmation Screen

Flow Diagram

Frontend

• Create Stripe Element for card payment.

<div id="card-element"></div>

• Mount the card element div with javascript

      document.addEventListener("DOMContentLoaded",  () => {
        const stripe = Stripe('pk_test_xxxxx');
        const element = stripe.elements();
        const cardElement = element.create("card");
        cardElement.mount("#card-element");
}

• Generate Token for the user entered card details

    <script>
      document.addEventListener("DOMContentLoaded",  () => {
        const stripe = Stripe('pk_test_xxxxxx');
        const element = stripe.elements();
        const cardElement = element.create("card");
        cardElement.mount("#card-element");


        $('#cardForm').off('click').on('click', function(e) {
      //  $("#cardForm").submit(function (e) {
          e.preventDefault();
          stripe.createToken(cardElement).then(function (result) {
            console.log(result);
            if (result.error) {
              console.log(result.error.message);
              $("#paymentError").html(result.error.message);
            } else {
              console.log(result.token.id);
             // $("#cardForm").html(result.token.id);
              $('#paymentToken').val(result.token.id);
              // alert($('#paymentToken').val())
              $("#cardForm").submit();
            }
          });
        });
      });
    </script>

Backend

• Get Prodcut information from Stripe

	public List<Product> getProducts() {

		try {
			Stripe.apiKey = stripeSecretKey;
			ProductListParams params = ProductListParams.builder().setActive(Boolean.TRUE).setLimit(Long.valueOf(3))
					.build();

			ProductCollection products = Product.list(params);
			return products.getData();
		} catch (Exception e) {
			LOG.error("",e);
		}
		return List.of();

	}

• Register Customer with Stripe

	private String createCustomer(CustomerInfo customer) throws StripeException {
		Stripe.apiKey = stripeSecretKey;

		CustomerCreateParams params = CustomerCreateParams.builder().setEmail(customer.getEmail())
				.setSource(customer.getPaymentToken()).build();
		Customer customerStripe = Customer.create(params);
		return customerStripe.getId();
	}

• Create PaymentInetent with Stripe

	public String createIntent(CartInfo cartInfo) throws StripeException {
		Stripe.apiKey = stripeSecretKey;

		String customerId = this.createCustomer(cartInfo.getCustomerInfo());
		PaymentIntentCreateParams paramsIntent = PaymentIntentCreateParams.builder()
				.setAmount((long) cartInfo.getAmountTotal()).setCurrency("jpy").setCustomer(customerId)
				.setConfirm(Boolean.TRUE).setCaptureMethod(CaptureMethod.MANUAL)
				.setDescription("Order for Customer " + cartInfo.getCustomerInfo().getEmail()).build();

		PaymentIntent charge = PaymentIntent.create(paramsIntent);
		return charge.getId();
	}

• Capture PaymentIntent with Stripe

	public String captureIntent(String id) throws StripeException {
		Stripe.apiKey = stripeSecretKey;

		PaymentIntent intent = PaymentIntent.retrieve(id);

		PaymentIntent updatedCharge = intent.capture();
		return updatedCharge.getId();
	}

Stripe also Provides the APIs something called Charge for businesses where payment intent is not a must. Like countries Japan

• Create Payment Charge with Strip

	public String createCharge(CartInfo cartInfo) throws StripeException {
		Stripe.apiKey = stripeSecretKey;
		String customerId = this.createCustomer(cartInfo.getCustomerInfo());
		ChargeCreateParams params = ChargeCreateParams.builder().setAmount((long) cartInfo.getAmountTotal())
				.setCurrency("jpy").setCustomer(customerId)
				// .setSource(cartInfo.getCustomerInfo().getPaymentToken())
				.setCapture(Boolean.FALSE).setDescription("Order for Customer " + cartInfo.getCustomerInfo().getEmail())
				.build();
		Charge charge = Charge.create(params);
		return charge.getId();
	}

• To run the application

java -jar stripecart-0.0.1-SNAPSHOT.jar

http://localhost:8080/