Passing Joda Time objects between the App layers

Question

I'm considering using Joda-Time.
I'm wondering if I should pay attention of what type of object my Interfaces are returning.
Returning Joda-Time objects from my interface signature on the service layer means that every module that use it will have be dependent on Joda-Time instead of the common java.util.Date API.
Are you passing Joda objects around your App modules or do you write wrappers in specific part of your app?

Answer 1

In the beginning, only return the most suitable type (Joda Objects in this case).

If you learn that someone has a problem with that (which probably won't happen too often), either add a converter method to the interface (so you have, say, getTime() and now getJavaTime() or getTimeInMillis()).

Or add a general purpose helper method which takes an Object (you can treat an unknown instance as Object anywhere in the code without having to import the actual Joda classes) and returns a plain Java object (java.util.Date).

Answer 2

What is the alternative ? Transforming jodaTime objects into infamous Calendar/Date objects ?

You chose to get rid of these objects and that's a good decision. Now, if you let other layers use the java date API, they'll go into the kind of bugs and non-sensical behaviours you got rid of by using jodaTime.

I think you should do your users a favor and let them use jodaTime.

Of course it's a design decision that'll add in their code a dependency to jodaTime, but I don't find it questionnable, as you chose jodaTime to write less and better code, and so should they.