This library solves the problem of ensuring that sensitive endpoints do not trigger side-effects multiple times - this is especially useful for any endpoints that handle financial operations. Currently, the library supports Spring MVC (Servlet-based) applications and MySQL and PostgreSQL with jdbc regarding storage backends. It is very simple to integrate, all that you have to do is add @Idempotent to any endpoints that need idempotency.

Full explanation of the functionalities and configuration is available in the readme of the repository. Repository : https://github.com/josipmusa/idempotency4j

I would love any feedback or review regarding the implementation - also, any recommendation is welcome.