Why do you use the Boolean Java Wrapper class?

[manuelkollus]

In my opinion, it is unnecessary to use the wrapper class from Boolean. But one would have used the primitive boolean.

kio-client-java/kio-client-java-api/src/main/java/org/zalando/stups/clients/kio/CreateOrUpdateApplicationRequest.java

Line 17 in 377ba2c

private Boolean active;

I don't know this project, neither do I know what it is used for but I can tell why they're using the Boolean object.

The reasoning behind it is to allow for JSON properties to serialize to null or deserialize from null. Sure, one could say that you can use primitives and let the primitive boolean initialize with a standard value, but then you couldn't tell whether or not the JSON was parsed correctly. You couldn't tell if the user or developer even provided a value for the active property which might or might not be a necessary value under some circumstances.

Using the Boolean allows a developer to check for null, where the primitive boolean cannot obtain a null value. It's either true or false.

Furthermore, REST requests/posts are also a thing. You don't want to default initialize the boolean primitive because this would be undefined behavior and you don't want that. Undefined behavior needs to be handled either by the client or the server.

Using the Boolean object instead of the primitive is totally legitimate. Happy to oblige.

[manuelkollus]

The sane design choice would be to create an Enum: BoolProperty (or some similair Name) and have following fields: TRUE, FALSE, UNINTIALIZED, where the third field indicates that the value did either not occur in the unstructured document or the parsing failed (even if a failed parsing should never return some invalid objects, but rather throw an exception). This way you are not playing around with dangerous null references and you have a third possible state.
Enums are prefect for that. Cheers

This issue is most likely to turn into a heated discussion. Suggesting to close this issue. @harti2006 @ChristianLohmann @mawenzel