NullPointerException where there's no possibility for one

Question

I'm trying to find a solution for a programme which I'm writing. The problem occurs even though I tried to prevent it and I don't seem to be able to find a mistake. This is the ''problematic'' part of my code:

if (this.s != null) {
        if (s.s != null && s.s.sta.length != 0) {
            for (int n = x; n < s.s.sta.length + x; n++) {
                    this.sos[n] = s.s.sta[n-x];
            }
            x = x + s.s.sta.length;
        }
}

I have an array STA which I'm using and a method which gives me the ''s'' neighbour of an object, so s.s is a neighbour of a neighbour.. What I'm trying to do is copy the objects from more than one specific neighbour into one array with many different if sentences. This one is an example but it doesn't work. Thank you and I really hope I get some info because I'm completely lost.

It would really help if you'd show a short but *complete* program demonstrating the problem - as well as identifying which line shows the error. — Jon Skeet, Jan 01 '15 at 21:34
You are checking if `s.s` is not null but I don't see nay check for `s.s.sta` or `this.sos`. — Pshemo, Jan 01 '15 at 21:35
The problem is that a program is meant for a school assignment and is very long. But the error comes from the line 4 of this part of programme. — Neža Đukič, Jan 01 '15 at 21:50
Ok will try this, but this.sos I'm still creating and therefore it is null now but I change it in this line. — Neža Đukič, Jan 01 '15 at 21:51
`"NullPointerException where there's no possibility for one"` -- 99.9% of the time, you're wrong and the JVM is right when you make such statements. — Hovercraft Full Of Eels, Jan 01 '15 at 21:52

score 1 · Answer 1 · answered Jan 01 '15 at 21:37

1

In the second line of your code you have:

if (s.s != null && s.s.sta.length != 0) {

You do check if s.s is null, but you do not check if s.s.sta is null.

answered Jan 01 '15 at 21:37

Paul

66
3

I did that and it solves this problem but in the other part that is identical to this which I also fixed, it is still giving me the same error. – Neža Đukič Jan 01 '15 at 21:56

NullPointerException where there's no possibility for one

1 Answers1