MoneyTransfer API 💸 💸

Table of Contents

• Introduction
• Documentation
• Data Model
• Architecture
• Testing
• Docker

Introduction

This project includes a SpringBoot application for handling financial transactions 💸 .
Update: Currency exchange is now performed to the transferred amount (if necessary) by fetching the latest exchange rates from "https://freecurrencyapi.com/"! 💱

Documentation

Powered by Swagger. Visit "http://localhost:8080/api/swagger-ui/index.html" to explore endpoints and try-out the app! 😊

Data Model

Account

The Account entity represents a bank account with the following properties:

Field	Description
account_id	Unique identifier of the account
balance	Decimal number representing the account balance
currency	Currency of the account (e.g., "GBP")
createdAt	Date and time when the account was created

Transaction

The Transaction entity represents a financial transaction between two accounts and includes the following properties:

Field	Description
transaction_id	Unique identifier of the transaction
source_account_id	ID of the account sending the funds
target_account_id	ID of the account receiving the funds
amount	Amount being transferred
currency	Currency of the transaction

TransactionRequest

The TransactionRequest entity provides idempotent behavior for POST transfer requests.

Field	Description
transactionRequest_id	Unique identifier of the TransactionRequest
transaction_id	ID of the successful Transaction
errorMessage	Error message
requestStatus	Status of the TransactionRequest
jsonBody	String representation of the jsonBody of the request

Architecture

Controller

• TransactionController

Data Transfer Objects (Dtos)

Container classes, read-only purposes.

Services

TransactionRequestService

Business Logic for executing a request for a financial transaction.

TransactionService

Business logic for performing a financial transactions between two accounts.

CurrencyExchangeService

Business logic for performing currency exchange.

Entities

• TransactionRequest
• Transaction
• Account

Repositories

JPA repository for each entity.

Exceptions

• Custom exceptions
• GlobalAPIExceptionHandler returns the appropriate HTTP status for each custom exception.

Testing

At the moment, integration tests for services are provided. More to come, as the app progresses! Note: Integration tests use H2 embedded db.

Acceptance Criteria

• AC 1: Happy path
• AC 2: Insufficient balance
• AC 3: Transfer in the same account
• AC 4: Source/target account does not exist

Docker

The app and (Postgres) db are now dockerized! ❤️ Let the magic happen by executing the following commands:

First-time setup:

docker compose up db --build
docker compose up app --build

Note: allow database setup to complete before starting the app container.

Subsequent runs:

docker compose up