I was looking at your tutorial: http://happycoding.io/tutorials/java-server/libraries
My question is, may I run Processing in the backend? For instance, if I want to create a service that accepts images, I use processing to create a B&W of it, and I deliver it. Would I need to run in headless mode ( I mean, simulating a graphic output in case the server does not have one running?) Would this work in any server hosting provider as discussed in your tutorial Hosting.
I am very interested in exploring this option and I hope I can get some insight from your wisdom.