A quick look at two Microservice Frameworks for Java.

Dropwizard

Dropwizard is a lightweight (for Java) 1 framework to build microservice back-ends with Java.

Dropwizard is a Java framework for developing ops-friendly, high-performance, RESTful web services. dropwizard.io

I became aware of Dropwizard as an engineer at Groupon, where it is used heavily as the basis for the official method of developing Java microservices. I know from a previous colleague it was used at HubSpot as well. Perhaps at other startups that started as a Rails monolithic app, reached a certain scale, and were broken up into microservices. The Ruby-to-Java history is discussed here 2 with the Coda Hale and Yammer background. This slide 3 shows roughly equivalent Rails and Dropwizard functionality for those coming from Rails.

I made a Hello World Dropwizard App to get a sense for developing with it, and deployed it to Heroku. I found Dropwizard to be ok to use, maybe not sparking the “Joy” of Sinatra and Ruby, but relatively lightweight for Java, and with very fast performance.

Javalin

Javalin is described as:

A simple web framework for Java and Kotlin

I made a Hello World App with Javalin and deployed it on Heroku, as a comparison with Dropwizard, in search of the lightest weight Java web framework.

I found it easy to use, and having even less code and setup compared with Dropwizard. For a very small API, if I was using Java, I’d consider implementing it with Javalin. If I was starting from scratch, I’d probably choose Kotlin over Java as well!

Wrapping Up

There are loads more Java microservice frameworks out there. What is your favorite one and why?

  1. Ruby frameworks like Sinatra are much lighter/less lines of code to get going ↩

  2. Dropping Rails for Dropwizard ↩

  3. Slide title: What does an application look like? ↩