How to create a picture in swing after some time?

Question

Java

https://github.com/DeadSidert/myGame
It's like a fight, 2 teams participate, there are archers and infantry.
Dealt with the infantry. but the archers ... how to create an arrow, so that later it can be manipulated like an infantryman?
I'm trying to do so. what if there are enemies on the battlefield. then the archers will try to shoot. but on condition. which is less on the battlefield. than 1 arrow per side. but create arrows then. when there are 0 of them on the battlefield