Parsing only methods specified in JsonBuilder interface from a given json

When I have a chance I'll do the same in the client.

Have a look and if you notice something wrong, let me know.
You have to check both getter and setters, because we can define interfaces only with setter, getters or both, but also you have to consider non getter/setter methods like:

interface A extends JsonBuilder {
   A xyz (int i);
   int xyz();
}