Eclipse suggests Null Pointer exception, though I believe I initialized my object

Question

As the title says I have NPE error. It happens on line:

while (getWidth() > bowl.getX()+10) {

If I remove it, it shows it happens on nex

Answer 1

The line:

GOval bowl = new GOval(10,10);

is declaring a new GOval and hiding the global GOval defined at the bottom.

That line should just be:

bowl = new GOval(10,10);

Answer 2

You are shadowing your bowl field at the class level in the init method,

private GOval bowl; 

public void init() {
  // GOval bowl = new GOval(10,10);
  bowl = new GOval(10,10);
  add(bowl);
  addMouseListeners();
}

Answer 3

Like most people already mentioned you are shadowing your bowl variable.

GOval bowl = new GOval(10,10);

should be replaced with

bowl = new GOval(10,10);

You can configure eclipse that he gives you a warning when you are doing this. In the preferences you have a dedicated part for this under java -> compiler -> errors/warnings