添加Person抽象类，要求属性包括用户名，性别等，方法包括各种构造函数，getter/setter方法、toString方法，equals方法，以及compareTo抽象方法。其中compareTo抽象方法原型如下：

　　public abstract int compareTo(Object another) //比较用户大小-Add Person abstract class, the attribute is required, including user name, gender, etc., methods including constructors, getter/setter methods, toString method, equals methods, and abstract method compareTo. One abstract method compareTo prototype is as follows:

public abstract int compareTo (Object another)// compare the size of the user