责任链模式

                   责任链模式（Chain of Responsibility）的目标是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。将这些对象连成一条链，并沿着这条链传递请求，直到有一个对象处理它为止。

              举个例子。你到银行去办理业务，只是简单的存个钱，也许ATM就解决你的问题。如果你是为了交费用的，那等去柜台，但你却是来咨询金融产品的，会有专员接待你，事实上你是一个大客户，经理就会把你请到他办公室好好和你谈谈，就这样。

               类图的关系如下：

                   

                

 

                  代码实现：

#ifndef BANKWORKER_H

#define BANKWORKER_H

#include <iostream>

using namespace std;

class BankWorker

{

public:

    BankWorker(int _standard, BankWorker *_pNext);

    virtual ~BankWorker();

    virtual void handle(int) = 0;

protected:

    int getStandard() const {return standard;}

    BankWorker* getNextWorker() const {return p_nextWorker;}

private:

    int standard;

    BankWorker *p_nextWorker;

};

#endif // BANKWORKER_H

 

#include "bankworker.h"

BankWorker::BankWorker(int _standard, BankWorker *_pNext):standard(_standard)

  ,p_nextWorker(_pNext)

{

}

BankWorker::~BankWorker()

{

    delete p_nextWorker;

    cout << "~~~\n";//能够帮助你了解析构的过称，更好的掌握继承

}

#ifndef ATM_H

#define ATM_H

#include "bankworker.h"

class ATM : public BankWorker

{

public:

    ATM(int _s,BankWorker *_p);

    ~ATM(){cout <<"ATM\n";}

    void handle(int client);

};

#endif // ATM_H

#include "atm.h"

ATM::ATM(int _s, BankWorker *_p):BankWorker(_s,_p)

{

}

void ATM::handle(int client)

{

    if (getStandard() > client) {

        cout << "ATM fall for you!\n";

    }

    else {

        if (getNextWorker() != NULL) {

            getNextWorker()->handle(client);

        }

    }

}

#ifndef COUNTERBOY_H

#define COUNTERBOY_H

#include "bankworker.h"

class Counterboy : public BankWorker

{

public:

    Counterboy(int _s,BankWorker *_p);

    ~Counterboy(){cout << "Counterboy\n";}

    void handle(int client);

};

#endif // COUNTERBOY_H

#include "counterboy.h"

Counterboy::Counterboy(int _s, BankWorker *_p):BankWorker(_s, _p)

{

}

void Counterboy::handle(int client)

{

    if (getStandard() > client) {

        cout << "Counterboy fall for you!";

    }

    else {

        if (getNextWorker() != NULL) {

            getNextWorker()->handle(client);

        }

    }

}

#ifndef MANAGER_H

#define MANAGER_H

#include "bankworker.h"

class Manager : public BankWorker

{

public:

    Manager(int _s = 0,BankWorker *_p = NULL);

    ~Manager(){cout << "manager\n";}

    void handle(int client);

};

#endif // MANAGER_H

#include "manager.h"

Manager::Manager(int _s, BankWorker *_p):BankWorker(_s, _p)

{

}

void Manager::handle(int client)

{

    cout << "I am Manager, I can do anything for you!" << '\n';

}

#include <iostream>

using namespace std;

#include "atm.h"

#include "counterboy.h"

#include "manager.h"

int main()

{

    Manager *p_m = new Manager();

    Counterboy *p_c = new Counterboy(10000,p_m);

    ATM *p_atm = new ATM(2000,p_c);

    p_atm->handle(30000);

    delete p_atm;

    return 0;

}

注：在此处只是以业务钱数的大小来分类，而且经理很牛，能解决一切问题，所以不会使请求得不到解决。