Spring Boot: RxJava

Back to posting, this will be a bit old since I had been working on this integration back in the February.

Interestingly enough I had already prepared a blog post related to this feature within Spring Cloud that added tight RxJava integration with Spring MVC controllers. Remarkably it turn out that the implementation in one of the previous milestones had a flow within it.

I’ve been interested in trying to find a solution towards the problem, though I was keen to support mostly the widely used REST like approach in which (mostly) the entire payload is being returned upon computation, in contrast to streaming the response over HTTP. This approach has been reflected in this small project:

https://github.com/jmnarloch/rxjava-spring-boot-starter

Which work out very well as a reference project, in which I had opportunity to try out different API implementations. On it’s own you can use this in your own project, since the proposed implementation depends only on the Spring Boot and Spring Framework’s MethodReturnValueHandler so if you simply using Spring Boot without additional features provided through Spring Cloud feel free to test it out.

Later the code of project become a baseline for the implementation proposed to

Spring Cloud approach

The final approach that has been implemented in Spring Cloud is a bit different, first of all the support for rx.Observable has been removed, instead you can use rx.Single in similar manner like DeferedResult, to which the underlying implementation in fact maps the RxJava type. The reference describes this a bit more in detail: http://cloud.spring.io/spring-cloud-static/spring-cloud.html#netflix-rxjava-springmvc

Funny enough at my company one of my colleagues had to later on migrate the code of one the projects from the rx.Observable to rx.Single, which he wasn’t really happy about 😉