public void move() {
//		TODO: 根据窗口大小判断
		if (x <= 0)
			moveToRight = true;
		else if (y >= 400)
			isAlive = false;
		else if (x >= 585)
			moveToRight = false;
		else if (y <= 25)
			moveToDown = true;
		if(moveToDown)
			y += YSPEED;
		else
			y -= YSPEED;
		if(moveToRight)
			x += XSPEED;
		else
			x -= XSPEED;
	}