public void act() 
    {
        // Add your action code here.
        getImage().scale(50,50);
        animationCounter++;
        patrol();
    }    
    
    public boolean canMove()
    {
        if(getObjectsInRange(20, Rock.class).isEmpty())
        {
            return(true);
        }
        else
        {
            return(false);
        }
    }
    
    public void patrol()
    {
            if(getY() <= 200 && getY() >= 50)
            {
                moveDown();
            }
            else
            {
                moveUp();
            }
    }

private int direction = 1; //1=down, -1=up

public void act()
{
    //do not scale the image in the act method. You can do that in the constructor (it only needs to be done once)
    if (getY()>200 || getY()<50) direction *= -1;
    setLocation(getX(), getY() + direction /** * speed */;
}