Question

I'm getting the error java.lang.NullPointerException even though I'm not using null in my code.
Can you tell me why and how I can fix it?

Answer 1

Not with the information provided. Sorry.

Answer 2

Maybe you haven't initialized some value?

Answer 3

This is a rough example of what can cause that error:

Lets say I have MainProgram.java and Data.java. In MainProgram.java I have:
```
ArrayList<Data> data;
```
So that `data` can be used as an array list of Data.java defined objects. Then I go on my merry way and use it:
```
data.add(new Data(1,2));
```
This will generate a null pointer error.

That first thing above is a declaration of what type `data` is. If I forget to do something like `data = new ArrayList<Data>` to initialize it in there, then I can't use it.

You probably have some situation like that going on, which is what blurbendy is talking about.