What does this error mean?

General Discussion Other

Alex Pilk..

in General Discussion • Other • 5 months ago

java.lang.NullPointerException

at processing.mode.java.runner.Runner.findException(Runner.java:925)

at processing.mode.java.runner.Runner.reportException(Runner.java:870)

at processing.mode.java.runner.Runner.exceptionEvent(Runner.java:813)

at processing.mode.java.runner.Runner$2.run(Runner.java:699)

Replies(8)

tfguy44

Re: What does this error mean?

5 months ago

It probably means that you've tried to access an object that you didn't create.
It's kind of hard for us to help you fix it without seeing the code that generated this error.

Alex Pilk..

Re: What does this error mean?

5 months ago

Thanks! The code is really big, and contains lots of images and music, so I don't think someone's gonna read this.

Could it happen because I didn't remove an object from ArrayList? This error happens eventually.

tfguy44

Re: What does this error mean?

5 months ago

Does it highlight a line of code when it generates this error?

You can check all the objects on that line to make sure you've created them.

Did you remember to initialize your ArrayList with "myArrayListName = new ArrayList()"?
Are you trying to access an object that was deleted from the ArrayList?
Are you trying to access an object in an ArrayList that is empty?

Alex Pilk..

Re: What does this error mean?

5 months ago

1. It doesn't highlight it.

2. Yes, I did, but outside setup() like this: "ArrayList<myClass> myArrayListName = new ArrayList()"

3. I don't think that there are empty objects. This is how I access them:

void access() {
if ( millis() > t1 ) {
myArrayListName.add(new myClass());
t1+=1950;
}
for(myClass a : myArrayListName){
a.appear();
}
if(myArrayListName.size() > 0){
for (int i = myArrayListName.size()-1; i > 0; i--){
if(myArrayListName.get(i).isDone()){ //This returns true if an image leaves the screen
myArrayListName.remove(i);
}
}
}

PhiLho

Re: What does this error mean?

5 months ago

The error happens not in your code, but in some internal part of Processing.
Is auto-format OK on your code?
Have you tried to close the PDE and restart it?

Alex Pilk..

Re: What does this error mean?

5 months ago

Yes, Ctrl+T works fine. I tried to close PDE and restart it, but I do not always get this error.

It happens sometimes, but usually sketch runs fine.

PhiLho

Re: What does this error mean?

5 months ago

I looked at Runner.java source code. It seems you have some kind of exception in your code, it tries to find which line fails in your code, from the exception information, and somehow fails doing so.
If it is still happens in 2.0b9, it might be worth reporting, but then it would be interesting to be able to reproduce it.
Do you use any special library in your code? Or only Minim?