How to trace a NullPointerException in a chain of getters

Question

If I get a NullPointerException in a call like this:

someObject.getSomething().getSomethingElse().
    getAnotherThing().getYetAnotherObject().getValue();
         


        

Answer 1

If you're having to get to the point where you're splitting up the line or doing elaborate debugging to spot the problem, then that's generally God's way of telling you that your code isn't checking for the null early enough.

If you have a method or constructor that takes an object parameter and the object/method in question cannot sensibly deal with that parameter being null, then just check and throw a NullPointerException there and then.

I've seen people invent "coding style" rules to try and get round this problem such as "you're not allowed more than one dot on a line". But this just encourages programming that spots the bug in the wrong place.