策略模式简单应用（结合简单工厂模式）:策略模式属于对象行为模式，其用意是针对一组算法，将每一个算法封装到具有共同接口的独立的类中，从而使它们可以相互替换。-Simple Mode policy applied (simple factory binding mode): Policy behavior patterns belong to the object, which is intended for a set of algorithms, each algorithm is encaps