On Mon, Jan 26, 2015 at 11:20 AM, Bernd Eckenfels <e...@zusammenkunft.net> wrote:
> Am Wed, 21 Jan 2015 05:45:08 -0700 (MST) > schrieb pike <pike...@hotmail.com>: > > > We frequently see NullPointerException in our logs. It's really a big > > headache when we see a NullPointerException and it is encapsulated in > > another exception as we don't know which object is null and it is > > throwing an Exception. Is there any way we can get to know the object > > type or the object variable name where the object is null and it is > > throwing a NullPointerException? i.e, instead of just saying there is > > a NullPointerException, can we add some friendly message? > > Note that if you keep the stack information in an exception it points > (most of the time) exactly to the location where the null access > happens. > > Maybe the objects in question are not talking only to their immediate friends <https://en.wikipedia.org/wiki/Law_of_Demeter>? This happens when we tend to do something like *a.getB().getC()* and we can't tell by looking at the NPE stack trace (which works on lines of source code) if *a* was null or what *a.getB()* returned was null. I can imagine it is rather hard for the VM to add more informations. > Your best bet is to avoid the NPEs and log the exceptions properly. > Gruss > Bernd >
