advice needed on checking for null object references

[Arne Vajhøj]

I find Java's sloppy distinctions between null and empty needs some
work. See http://mindprod.com/jgloss/empty.html

Java has very well defined distinction between null and empty string.

> Java is going to check it for you anyway. So you can count on stack
> dump and termination.

There is not too much point in

assert x != null : "x null";

since that will happen anyway.

There is absolutely point.

There is always point in getting the exception where the
problem arise instead of some random place further ahead/down
the code.

Arne

 

[Lew]

That will most assuredly not happen anyway. What will happen "anyway" is a
NullPointerException, not an assertion failure.

There is absolutely point.

There is always point in getting the exception where the
problem arise instead of some random place further ahead/down
the code.

Exactly so. Furthermore, there is a world of difference between an assertion
and an exception. Exceptions enforce invariants; they cause them to be true.
Assertions do not. Assertions prove and document invariants, but they are
explicitly incapable of enforcing them.