In order to improve my kunFu (my TDD, my Java, and my work in general), I'm planning doing some katas, and publishing here. If somebody want to see how I solve them. Based on 12meses12katas web (thanks @kinisoftware for your effort on this initiative!!). The first one, String Calculator, I solved there: I've packaged the code here: String Calculator Java Kata. And you can see immediately at Git Hub repo. Hope you enjoy as much as I did programming it( sure, I enjoy pretty much programming!! I think that it isn't so weird, is it? ;-P )