How to fill all the fields in the class?

Question

Suppose I have a class that has a lot of different fields. This class is a DTO and for testing purposes, I do not care about actual values, just it exists. Is there any tool

Answer 1

Is there any tool that can traversal through all fields and set primitives, 0 for Number (0.0 for Float, Double, 0 for Integer, 0L for Long, but not null as default), something like "test" for String? Also I want that tool to populate Collections (List, Set, Map).

AFAIK, there is nothing that will save you much effort over doing it the simple way. It is a trivial matter to declare the fields with an initializer, or to do some simple default initialization in the constructor(s).

It is probably a good idea to use primitive types rather than wrapper types; e.g. int rather Integer. One advantage is that fields with primitive types are default initialized to 0, 0.0 or false ... saving you the bother.