Object hierarchical call in JAVA

Question

I have a question regarding the Object hierarchical call.

I have four classes namely A, B, C, D.

D will be set in C; C will be in B; B will be in A.

If I want to do something in class D, I have to call a.b.c.d.setWidth("50%");(a, b, c, d are instance of Class A, B, C, d).

Is that fine to call like that? Will that compromise the performance?

Answer 1

The effect on performance will be very slight... the bigger issue is what that does to your object-oriented model.

Having direct access to the members of a class is frowned apon, and you are running risks of NullPointerExceptions.

What you should be more worried about is the readability and maintainability of your code.

Answer 2

It is perfectly legal to call like that. I dnt think it will have performance issues. But the design is not good. You should use getters and setters inside the code. For example : In your case : a.getB().getC().getD().setWidth("50%").

In class A , declare variable of B as private and similarly with class B and C. It will ensure data hiding and encapsulation principles of an Object Oriented design.