I'm making a game in Java with Slick2D and I want to create planes which shoots:

int maxBullets = 40;
static int bullet = 0;
Missile missile[] = new Missile[maxBullets];

I want to create/move my missiles in the most efficient way, I would appreciate your advise:

public void shoot() throws SlickException{
    if(bullet<maxBullets){
        if(missile[bullet] != null){
            missile[bullet].resetLocation(plane.getCentreX(), plane.getCentreY(), plane.image.getRotation());
        }else{
            missile[bullet] = 
            new Missile("resources/missile.png", plane.getCentreX(), plane.getCentreY(), plane.image.getRotation());
        }
    }else{
        bullet = 0;
        missile[bullet].resetLocation(plane.getCentreX(), plane.getCentreY(), plane.image.getRotation());
    }
    bullet++;
}

I created the method resetLocation in my Missile class in order to avoid loading again the resource. Is it correct?

In the update method I've got this to move all the missiles:

if(bullet > 0 && bullet < maxBullets){   
    float hyp = 0.4f * delta;
    if(bullet == 1){
        missile[0].move(hyp);
    }else{
        for(int x = 0; x<bullet; x++){
            missile[x].move(hyp);
        }
    }       
}