And to go even lighter I use pippo(https://github.com/decebals/pippo). I like the modular way that allows me to tailor my apps to be <1MB final size. Really helps with lightning fast deployments on my many DigitalOcean smallest 512MB instances.It also works great on raspberry pies - I was using nodejs webapps until pippo because they were lighter on resources(I rather hate js and nodejs and hence the praise for pippo) .
I also pair it with jooq for db access when needed.
I'm trying pippo for the last couple of weeks, its quite lightweight and really fast. I could customize it for whenever the need arises, better than sparkjava. For eg: I couldn't customize the Jetty server params with sparkjava, I could with pippo.
Unfortunately the actual documentation of Pippo it's a little bit behind of the implementation (from documentation are missing some nice concepts: named routes, finally filters, custom route context, ...) and from this reason I cannot give you more useful links but I will fix this aspect asap.
Another difference in Pippo to other (micro) java web framework (spark, ninja) is that a RouteHandler it's a real endpoint (the handle method return void). You can finalize/commit the response using send, render, redirect. Everything is transparent.
