This is an currency exchange application which utilizes external web services for currency conversions.
This is a Spring Boot application which serves HTTP requests in order to convert between currencies at latest rates. The application utilizes multiple exchange rates providers.
Running these commands:
mvn clean install
java -jar target/exchange-0.0.1-SNAPSHOT.jar
After running the application, you can hit localhost:8081/api/v1/convert endpoint with a POST request, which body is as below:
{
"from" : string ("EUR", "USD", etc) ,
"to" : string ("EUR", "USD", etc) ,
"amount" : number
}
By validating inputs such as currency names and amount, /convert endpoint returns the amount calculated by rates which are stored in a Caffeine cache. If one of the providers API is down for any reason, a circuit breaker is used for falling back into another provider API.
For every request, there is an async update of the cache in case the cache is empty, and also there is a scheduled job in place which updates the cache once in a while.
Sequence diagram:
This application uses Swagger for API documentation. In this case there is only one endpoint:
There is a 92% testing coverage using Mockito and JUnit libraries for mocking and asserting.
