I think it's little bit difficult to give you a correct answer. Frankly speaking, cap file debugging is possible if you have sufficient devices and knowledge to do that. Converting cap file to java source code is also possible only if the cap file has descriptor component in it. Names of variables, functions will not be completely restored because cap file doesn't have the names in it. But I am not sure that there is a publicly opened tool to do that. JCVM chapter 6 may show you the way even it's not the direct one.