摘要：什么是访问者模式？ Definition：Represent an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which... 阅读全文

摘要：什么是状态模式？ Definition: Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. 当对象有几种状态时，不同状态时有不同的表现，为了避免复杂的ifelse逻辑，将每个状态的逻辑单独封装... 阅读全文

摘要：什么是中介者模式？ Mediator Pattern Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it ... 阅读全文

摘要：什么是备忘录模式？ Without violating encapsulation, capture and externalize an object’s internal state so that the object can be returned to this state later. 其实‘人’如其名，备忘模式就是为了对一个对象做备忘，允许做类似“重播”、... 阅读全文

摘要：什么是命令模式？ GoF的书的定义为：“Command pattern encapsulate request as an object, thereby letting you parameterize clients with different request, queue or log request, and support undoable operations” 换言之，讲命令封... 阅读全文

摘要：什么是责任链模式？ wikipedia的定义为：CoR pattern consists of a source of command objects and a series of processing objects. Each processing object contains a set of logic that describes the types of comman... 阅读全文

摘要：什么是策略模式？ wikipedia的定义为：Strategy Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from clients that use it.... 阅读全文