Linux C++ 047-设计模式之责任链模式

Linux C++ 047-设计模式之责任链模式

本节关键字：Linux、C++、设计模式、责任链模式
相关库函数：

简介

责任链模式是面向对象中的一种软件设计模式，它包含了一些命令对象和一些处理对象，每个处理对象决定它能处理那些命令对象，它也知道应该把自己不能处理的命令对象交下一个处理对象，该模式还描述了往该链添加新的处理对象的方法。

代码示例

class Request
{
public:
    string requestType;
    string requestContent;
    int number;
};
class Manager
{
protected:
    string name;
    Manager* superior;
public:
    Manager(string name) {
        this->name = name;
    }
    void setSuperior(Manager* superior) {
        this->superior = superior;
    }
    virtual void requestApplications(Request* request) = 0;
};
class CommonManager : public Manager
{
public:
    CommonManager(string name) :Manager(name)
    { }
    void requestApplications(Request* request) {
        if (request->requestType == "qingjia" && request->number <= 2) {
            cout << name << " " << "pizhun" << request->requestContent << "number: " << request->number << endl;
        }
        else {
            if (superior != NULL) {
                superior->requestApplications(request);
            }
        }
    }
};
class Majordomo : public Manager
{
public:
    Majordomo(string name) : Manager(name)
    { }
    void requestApplications(Request* request) {
        if (request->requestType == "qingjia" && request->number <= 5) {
            cout << name << " " << "pizhun" << request->requestContent << "number: " << request->number << endl;
        }
        else {
            if (superior != NULL) {
                superior->requestApplications(request);
            }
        }
    }
};
class GeneralManager : public Manager
{
public:
    GeneralManager(string name) : Manager(name)
    { }
    void requestApplications(Request* request) {
        if (request->requestType == "qingjia") {
            cout << name << " " << "pizhun" << request->requestContent << "number: " << request->number << endl;
        }
    }
};
int main_Request()
{
    CommonManager* jingli = new CommonManager("jingli");
    Majordomo* zongjian = new Majordomo("zongjian");
    GeneralManager* zongjingli = new GeneralManager("zongjingli");

    jingli->setSuperior(zongjian);
    zongjian->setSuperior(zongjingli);

    Request* request = new Request();

    request->requestType = "qingjia";
    request->requestContent = "LI qingjia";
    request->number = 1;
    jingli->requestApplications(request);

    request->requestType = "qingjia";
    request->requestContent = "LI qingjia";
    request->number = 4;
    jingli->requestApplications(request);

    request->requestType = "qingjia";
    request->requestContent = "LI qingjia";
    request->number = 10;
    jingli->requestApplications(request);
    return 0;
}
/* 运行结果：
jingli  pizhun LI qingjia number: 1
zongjian  pizhun LI qingjia number: 4
zongjingli  pizhun LI qingjia number: 10
*/
// 对于抽象基类的派生类：经理类，总监类，总经理类都能够处理请求，只不过根据请求的内容不同，他们自己如果不能处理，需要请求自己的上级处理，那么在这里面需要定义设置自己的上级以及处理请求的成员函数
// 客户端：实例化请求对象，以及经理对象，并初始化请求对象的内容以及经理之间的上下级关系，请求直接交给最底层的经理来处理即可（它内部直到这个请求最终谁有权力处理）
//