Chain of Responsibility 职责链模式

 

  GOOD：使多个对象都有机会处理请求，从而避免请求的发送者和接收者之间的耦合关系。将这个对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理为止。

 

例：

#include <iostream>

#include <string>

#include <vector>

using namespace std;

//请求

class Request

{

public:

       string m_strContent;

       int m_nNumber;

};

//管理者

class Manager

{

protected:

       Manager* manager;

       string name;

public:

       Manager(string temp)

       {

              name = temp;

       }

      void SetSuccessor(Manager* temp)

      {

             manager = temp;

      }

       virtual void GetRequest(Request* request) = 0;

};

//经理

class CommonManager : public Manager

{

public:

       CommonManager(string strTemp) : Manager(strTemp){}

       virtual void GetRequest(Request* request)

      {

             if ( request->m_nNumber>=0 && request->m_nNumber<10 )

             {

                    cout<<name<<"处理了"<<request->m_nNumber<<"个请求"<<endl;

             }

             else

             {

                    manager->GetRequest(request);

             }

      }

};

//总监

class MajorDomo : public Manager

{

public:

       MajorDomo(string name) : Manager(name){}

 

       virtual void GetRequest(Request* request)

       {

              if(request->m_nNumber>=10)

              {

                  cout<<name<<"处理了"<<request->m_nNumber<<"个请求"<<endl;

              }

       }

};

 

//客户端

int main()

{

       Manager * common = new CommonManager("张经理");

       Manager * major = new MajorDomo("李总监");

      

       common->SetSuccessor(major);

      

       Request* req = new Request();

       req->m_nNumber = 33;

       common->GetRequest(req);

      

       req->m_nNumber = 3;

       common->GetRequest(req);

       return 0;

}