Ray's playground

摘要： There are three common situations in which you would consider using this pattern: Your subsystem is getting complex. A lot of classes are evolved fromapplying patterns. You can use a façade to provide a simpler interfacefor the subsystem classes. You can use façades to layer your subsystem 阅读全文

摘要： Abstraction is the parent interface that defines the high-level abstraction interface usedby clients. It has a reference to an instance of Implementor, which defines the interfacefor implementation classes. This interface doesn’t need to correspond to Abstraction’sinterface; in fact, they can be qu. 阅读全文