How to paint a laser that shows gun heading

[z***@gmail.com]

I want to see the robot's gun aiming trajectory. Basically a line that
originates from the robot and ends at the at a point where the robot is
currently aiming at.

public void onPaint(Graphics2D g){

int laserLength = 200;
double heading =getGunHeading();
g.setColor(Color.RED);

double x = Math.sin(Math.toRadians(heading)) * laserLength;
double y = Math.cos(Math.toRadians(heading)) * laserLength;
g.drawLine((int)getX(),(int) getY(), (int)x,(int) y);

}

Laser points at an irrelevant direction. How can I fix it?