Try loading a class or properties file as a resource, then look at the path for the resource. That should get you the information you need.
I think this code will work (substituting the class names with classes in your app):
Class class1 = ClassInApp.class;
URL url = class1.getResource("ClassInApp.class");
String s = url.toString();
The string 's' should contain the full path to the class file, which contains the tmp/deploy directory.