Like any other built-in Java library - you need to import it. For example (make sure you know how to quit using Escape!)
import java.awt.Robot;
Robot robot;
int x,y;
void setup() {
try {
robot = new Robot();
} catch (Exception ex) {
println(ex);
}
}
void draw() {
x++;
x %= 500;
y++;
y %= 500;
robot.mouseMove(x,y);
}
If you’re using P2D / P3D it’s better to use the JOGL library for this though.