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

Chained expressions like that are a pain to debug for NullPointerExceptions (and most other problems that can occur) so I would advise you to try and avoid it. You have probably heard that enough though and like a previous poster mentioned you can add break points on the actual NullPointerException to see where it occurred.

In eclipse (and most IDEs) you can also use watch expressions to evaluate code running in the debugger. You do this bu selecting the code and use the contet menu to add a new watch.

If you are in control of the method that returns null you could also consider the Null Object pattern if null is a valid value to return.