I have decided to use DDD concept, mainly on Length class for some reasons:
No classes inside my application knows that internally I'm using a BigDecimal, I could have used anything. I would be able to exchange the implementation if needed for performance reasons or memory reasons and my code base would not be affected. It's encapsulation.
I decided to use factory methods in order to produce objects in place of using new Length()
constructor. The problem of new Length()
that is not a refactor-friendly. In my implementation, if I want to create another type of Length I just need to create another factory method because all the logic of object creation will be inside of the factory methods.
I can check the state of the object on the factory method. I'm reducing the logic validation to only one method on my code, if there is a Length object on my application I know that it is correct, because it's being validated before the object creation, by doing this I can assure that my object will always be valid.