Kotlin Ktor Exposed Starter

This is a starter project for a RESTful API application, implemented in Kotlin using Ktor, Exposed, and an H2 in-memory database.

Author: Ebubekir Yiğit

Objective: The application serves as a demonstration of a simple financial transfer system, allowing customers to transfer funds from their wallet to a restaurant's account upon making a purchase.

Features

The application can transfer funds from a customer's wallet to a restaurant's account.
The transfer operation validates that the customer has sufficient funds in their wallet and that the transfer amount does not exceed their daily limit.
The application can display the balances in both customer and restaurant accounts.

Prerequisites

You need to have Kotlin and Java installed on your local machine. This guide assumes you have the Java Development Kit (JDK) version 11 or higher installed.

Getting Started

Running the Application

To start the application, run the following command in the root directory of the project:

./gradlew run

Running the Tests

To run the tests, use the following command:

./gradlew test

Endpoints

POST /transactions: Takes the TransferRequest object and transfers the amount from the customer's account to the restaurant's account.

Transaction Request:

{
    "customerId": 2,
    "restaurantId": 1,
    "amount": 3.5
}

Transaction Response:

{
    "success": true,
    "data": {
        "transactionId": 1,
        "customerId": 2,
        "restaurantId": 1,
        "amount": 3.5
    }
}

GET /accounts/customer/{id}: Returns the balance of the customer's account with the given id.
GET /accounts/restaurant/{id}: Returns the balance of the restaurant's account with the given id.

Account Balance Response:

{
    "success": true,
    "data": {
        "accountId": 2,
        "balance": 26.5
    }
}

Project Structure

├── main
│   ├── kotlin
│   │   ├── database       # Database initialization, migration etc.
│   │   ├── models         # Request, Response and DB Models
│   │   ├── repositories   # Database actions, storage layer
│   │   ├── routes         # Endpoint definitions
│   │   └── services       # Business logic
└── test
    └── kotlin
        ├── api            # API tests
        └── service        # Service tests

Acknowledgments

This project uses the following libraries:

ebubekiryigit/kotlin-ktor-exposed-starter