idempotency4j - Java/Spring Boot Idempotency Library
The last couple of months, I ended up implementing idempotency in 2 different Spring Boot projects back to back.
As I was implementing it in the second project, I decided to look up any existing solutions/libraries for Java/Spring Boot, but I honestly couldn't find one that felt clean and flexible enough for what I needed (and what most people probably need).
So I decided to build my own and open source it.
I released it about a month ago:
Repository : https://github.com/josipmusa/idempotency4j
Maven spring boot starter : https://central.sonatype.com/artifact/io.github.josipmusa/idempotency-spring-boot-starter
The goal was to make idempotency implementations feel straightforward and easy, but also to not scope it only to spring boot or a certain storage implementation. The library has a core which can be used on any method with pluggable storage backends. It also has an integration with spring web (servlet-based for now) and a spring boot starter to simplify usage.
Usage example for a spring boot project:
@PostMapping("/payments")
@Idempotent
public ResponseEntity<Payment> createPayment(@RequestBody PaymentRequest request) {
// Runs exactly once per unique Idempotency-Key value.
// Subsequent identical requests get the stored response replayed.
return ResponseEntity.ok(paymentService.charge(request));
}
Right now it supports:
- Spring MVC (Servlet-based apps)
- JDBC storage (so it works out of the box with MySQL / PostgreSQL setups most people already have)
- In-memory storage
- duplicate request detection
- replaying previous responses
- concurrent request protection
- request fingerprinting
- configurable TTLs
- pluggable storage backends
Curious whether others have run into this same problem and whether this library helps solve it for them.
Open to any feedback, suggestions, or reviews.