Payment Gateway

Requirements

• JDK 17
• Docker

Setup

• Run Docker then create a container using the docker-compose file
• Import the API collection in Postman
• Run the application

API Documentation

For documentation openAPI is included, and it can be found under the following url: http://localhost:8090/swagger-ui/index.html

Usage

Create payment endpoint

POST http://localhost:8090/payment

Example request

{
  "cardNumber": "2222405343248877",
  "cvv": "123",
  "expiryMonth": 4,
  "expiryYear": 2025,
  "currency": "GBP",
  "amount": 100
}

Example response

{
  "id": "5a5dab4d-b07c-41a9-a1a8-f7c96c609cb5",
  "status": "Authorized",
  "cardNumberLastFour": "8877",
  "expiryMonth": 4,
  "expiryYear": 2025,
  "currency": "GBP",
  "amount": 100
}

Get payment endpoint

POST http://localhost:8090/payment/{{paymentId}}

Example response

{
  "id": "19f3c9f1-1384-45c2-ac36-b41f90111446",
  "status": "Authorized",
  "cardNumberLastFour": "8877",
  "expiryMonth": 4,
  "expiryYear": 2025,
  "currency": "GBP",
  "amount": 100
}

Note:

• The unauthorized scenario cannot be tested as the bank simulator expects an invalid card number.
• The payment gateway will return a 400 status code if the request is invalid.
• The payment gateway will return a 500 status code if the bank simulator cannot handle the request.

Possible improvements

• Merchant accounts with API authentication
• Persistent storage for payments
• More detailed Swagger documentation with examples