"软件体系结构与设计模式-第七章策略模式详解"

The Strategy Pattern, also known as the Policy Pattern, is a design pattern that defines a family of algorithms, encapsulates each algorithm, and makes them interchangeable. This pattern allows the algorithms to vary independently from the clients that use them. The Strategy Pattern is a mature pattern for handling different variants of algorithms. It encapsulates the identification of the algorithm through an interface or abstract class, defining an abstract method in the interface, and the classes implementing the interface will implement the abstract method. The structure of the Strategy Pattern includes three roles: the Strategy, the ConcreteStrategy, and the Context. The Strategy represents the interface or abstract class encapsulating the algorithm. The ConcreteStrategy represents the classes implementing the Strategy interface. The Context uses a Strategy and provides a method for clients to set the strategy. The key benefit of the Strategy Pattern is that it allows for the algorithm to vary independently from the clients using them. This makes the system more flexible, easier to maintain, and easier to extend. It also enables the swapping of different algorithms without affecting the clients using the algorithms. In summary, the Strategy Pattern is a powerful design pattern for encapsulating algorithms, making them interchangeable, and allowing for independent variation. It provides a flexible and maintainable solution for handling different variants of algorithms within a software system.