结构型模式之适配器模式

设计模式 

创建模式之单例模式

问题：

假如你正在开发一款股票市场监测程序(client)， 它会从不同来源下载 XML 格式的股票数据， 然后向用户呈现出美观的图表。

在开发过程中， 你决定在程序中整合一个第三方智能分析函数库(server)。 但是遇到了一个问题， 那就是分析函数库只兼容 JSON 格式的数据。

你可以创建一个适配器。 这是一个特殊的对象， 能够转换对象接口， 使其能与其他对象进行交互。

 

 main.cc: 概念示例   ：同时继承client和server，

/** * The Target defines the domain-specific interface used by the client code. */ class Target { public: virtual ~Target() = default; virtual std::string Request() const { return "Target: The default target's behavior."; } }; /** * The Adaptee contains some useful behavior, but its interface is incompatible * with the existing client code. The Adaptee needs some adaptation before the * client code can use it. */ class Adaptee { public: std::string SpecificRequest() const { return ".eetpadA eht fo roivaheb laicepS"; } }; /** * The Adapter makes the Adaptee's interface compatible with the Target's * interface using multiple inheritance. */ class Adapter : public Target, public Adaptee { public: Adapter() {} std::string Request() const override { std::string to_reverse = SpecificRequest(); std::reverse(to_reverse.begin(), to_reverse.end()); return "Adapter: (TRANSLATED) " + to_reverse; } }; /** * The client code supports all classes that follow the Target interface. */ void ClientCode(const Target *target) { std::cout << target->Request(); } int main() { std::cout << "Client: I can work just fine with the Target objects:\n"; Target *target = new Target; ClientCode(target); std::cout << "\n\n"; Adaptee *adaptee = new Adaptee; std::cout << "Client: The Adaptee class has a weird interface. See, I don't understand it:\n"; std::cout << "Adaptee: " << adaptee->SpecificRequest(); std::cout << "\n\n"; std::cout << "Client: But I can work with it via the Adapter:\n"; Adapter *adapter = new Adapter; ClientCode(adapter); std::cout << "\n"; delete target; delete adaptee; delete adapter; return 0; }

Output.txt: 执行结果

Client: I can work just fine with the Target objects: Target: The default target's behavior. Client: The Adaptee class has a weird interface. See, I don't understand it: Adaptee: .eetpadA eht fo roivaheb laicepS Client: But I can work with it via the Adapter: Adapter: (TRANSLATED) Special behavior of the Adaptee.