Hello, I'm a beginner in Java and I'm trying to create a jpanel that
creates 10 concentric circles with random radius. But I'm having a bit trouble with it.

Here are my codes:

When I run this, I get only one circle (sometimes none...)
if i set radius = generator.nextInt(MAX_DIAMETER) + 1;

But if i replace MAX_DIAMETER which is 600, to something small maybe 100.
radius = generator.nextInt(100)+1;
than i get 5-10 circles...

When I run this, I get only one circle (sometimes none...)
if i set radius = generator.nextInt(MAX_DIAMETER) + 1;

But if i replace MAX_DIAMETER which is 600, to something small maybe 100.
radius = generator.nextInt(100)+1;
than i get 5-10 circles...

What am i doing wrong??

The radius of the circle is (diameter/2)
"generator.nextInt(MAX_DIAMETER) "when you are using this function that's mean you are expecting a random number from 0-600
so when you write the code diameter=2*radius....actually the diameter at most of the time becomes as big as 1200,and your panel size is (600,600) so it won't suit the created circles.