Case Study - Foreign Exchange Example

📖 Information

• This project demonstrates a Spring Boot application for managing foreign exchange operations. It allows users to convert currencies, retrieve current exchange rates, and view conversion history.
• The application integrates with an external service provider for fetching exchange rates and performing currency conversion calculations.
• The application includes three main endpoints:
  • Exchange Rate Endpoint: Fetches the current exchange rate between two currencies.
  • Currency Conversion Endpoint: Converts a given amount from one currency to another and returns a unique transaction identifier.
  • Conversion History Endpoint: Retrieves the history of currency conversions based on transaction identifiers or dates.

Explore Rest APIs

Endpoints Summary

Method	Url	Description	Request Body	Path Variable	Response
POST	/api/v1/exchange-rate	Fetches the current exchange rate between two currencies.	ExchangeRateRequest	None	ExchangeRateResponse
POST	/api/v1/convert	Converts currency based on the provided ConvertRequest.	ConvertRequest	None	ConvertResponse
POST	/api/v1/history	Retrieves the conversion history based on the provided ConversionHistoryFilterRequest.	ConversionHistoryFilterRequest	None	CustomPage<ConvertHistoryResponse>

Technologies

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• Java 21
• Spring Boot 3.0
• Restful API
• Mapstruct
• Open Api (Swagger)
• Maven
• Junit5
• Mockito
• Integration Tests
• Docker
• Docker Compose
• CI/CD (Github Actions)
• Postman
• H2 Database (In-Memory)
• Spring Boot Actuator
• Spring Cache
• Resilience4j (Rate Limiter)

Postman

Import postman collection under postman_collection folder

Prerequisites

Define Variable in .env file for http://api.currencylayer.com/

EXCHANGE_API_API_KEY={EXCHANGE_API_API_KEY}

Open Api (Swagger)

http://localhost:1331/swagger-ui/index.html

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• Maven or Docker

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Docker Run

The application can be built and run by the Docker engine. The Dockerfile has multistage build, so you do not need to build and run separately.

Please follow directions shown below in order to build and run the application with Docker Compose file;

$ cd foreignexchangeexample
$ docker-compose up -d

If you change anything in the project and run it on Docker, you can also use this command shown below

$ cd foreignexchangeexample
$ docker-compose up --build

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Maven Run

To build and run the application with Maven, please follow the directions shown below;

$ cd foreignexchangeexample
$ mvn clean install
$ mvn spring-boot:run

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Docker Image Location

https://hub.docker.com/repository/docker/noyandocker/foreignexchangeexample/general

Screenshots

Click here to show the screenshots of project

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Contributors

• Sercan Noyan Germiyanoğlu