how does a swing timer work?

Question

hello i am having trouble trying to understand swing timers. to help me could someone show me a simple flickering animation? i have looked arround on the internet but still

Answer 1

I think a paint method would work.like this:

public void paint(Graphics g){
super.paint(g);

g.setColor(Color.green);
g.filloval(30,40,50,50);
 }