This api was built using spring boot with spring data and spring cache api. For simplicity the database is H2 and the cache is Caffeine, that is an in-memory cache.
When a get is performed, the api try to get the conversion rate in the treasury api, but first try to get the conversion in cache. Conversion rate of the last 6 month does not change with frequency, so caching this data is a good way to improve performance.
It's possible to get a purchase converted to a specific currency in 3 ways:
- By passing a currency in a request query param:
/purchage/1?currency=BRL - By passing a country name in english in a request query param:
/purchage/1?country=Brazil - By not passing anything. This way the api will get the locale of the request and convert to the corresponding currency.
Saving a purchase is required to specify the description. This validation is made using the validation framework of spring boot. The amount, the minimum accepted is 1.0.
The database used in this api is an H2 database and the schema is initialized with liquibase.
All the responses are translated for english and portuguese using resource bundle, and it's treated using ResponseEntityExceptionHandler in GlobalAdviceHandler class.
For simplicity only unit tests was made.