I recently discovered FRAPI for PHP. It's a REST Web Services High-level API provider that lets you build REST API web services easily, it has three great features:
In order to build a web services you just need to specify the end points using their web based GUI, and then you focus on writing your business logic without deal with HTTP complexity.
Do you know if exists a lightweight open source alternative that provides one or more of this features like FRAPI but for Java?
I found WSO2 Api Manager that lets you do this similarly and it's language agnostic because it's like an Enterprise Service Bus, it's great but I'm searching for something that it's more lightweight and simple.
Any info will be highly appreciated, thanks.
You can use the Spring MVC to build your Rest Web Services easily. Spring ROO can help you to set up a skeleton project from which you can learn how to set it up for your project.
Here is a demo which shows you how to use Spring ROO to build a RESTful Web Services: http://www.youtube.com/watch?v=TNE7NBLseRA
I don't know if there is any ROO addon can generate API keys for your web services but you can use Spring Security to secure your web services.