java casting problem

so I have a class called "test", In another class i have created an arraylist<objects> list but it wont let me cast the test object into the arraylist. It is giving me a null.pointer.exception

so I use list.add(new test());

What am I missing or what am i doing wrong

well, as much as I'd like to hone my psychic powers in figuring out your problem with a basic description, it appears my powers are sadly limited, so you'll have to post the code so that I can see the problem.

i would but we got the problem solved. The arraylist wasn't initialized correctly