How to avoid null checking in Java?

Question

I use object != null a lot to avoid NullPointerException.

Is there a good alternative to this?

For example I often use:

Answer 1

Sometimes, you have methods that operate on its parameters that define a symmetric operation:

a.f(b); <-> b.f(a);

If you know b can never be null, you can just swap it. It is most useful for equals: Instead of foo.equals("bar"); better do "bar".equals(foo);.