说明：  贪吃蛇 Java源代码 此类是贪吃蛇的简单实现方法 * 自己可以加入在开始时的设置，比如 * 选关，初始的蛇的长度等等
(Snake Java source code of these are the easy implementation Snake Ways* they can add at the beginning of the settings, such as* elected clearance, the initial length of the snake and so on)