Show HN: Java-tutorial for forms and upload

Looks very nice and concise. A few suggestions:

- You should make those endpoints restful with resources rather than using action verbs (just a best practice so that APIs are consistent and readable)

- Maybe this is a nitpick, but ctx/context is a term that appears across many Java frameworks. When I think of context, it has to do with global framework full (Spring Context, base framework classes, etc) rather than request/response objects.

- Can you provide a snippet of unit test code for the class?

- Any advice on advanced input validation?

Very good work.