c++ 中介者模式（mediator）

中介者模式:用一个中介对象来封装一系列的对象交互。中介者使各个对象不需要显示地相互引用，从而使其耦合松散，而且可以独立地改变他们之间的交互。中介者模式的例子很多，大到联合国安理会，小到房屋中介。下面以房屋中介来介绍中介者模式。

#include <iostream>
#include <string>

using namespace std;

class Mediator;

class Person
{
public:
    virtual void setMediator(Mediator* mediator){};
    virtual void sendMessage(string msg) = 0;
    virtual void getMessage(){};
protected:
    Mediator *m_mediator;
};

class Mediator 
{
public:
    virtual void setHost(Person* p) = 0;
    virtual void setClient(Person* p) = 0;
    virtual void sendMsg(Person* p,string msg)
    {
    
    }

}; 

class HouseMediator:public Mediator
{
public:
    void setHost(Person* p)
    {
        m_host = p;
    }
    void setClient(Person* p)
    {
        m_client = p;
    }
    void sendMsg(Person* p,string msg)
    {
        if(p == m_host)
        {
            m_client->getMessage();
        }
        else
        {
            m_host->getMessage();
        }
    }
private:
    Person* m_host;
    Person* m_client;
};

class HostPerson:public Person
{
public:
    void setMediator(Mediator* mediator)
    {
        m_mediator = mediator;
    }
    void sendMessage(string msg)
    {
        m_mediator->sendMsg(this,msg);
    }
    void getMessage(string msg)
    {
        cout << "房东收到消息！" <<endl;
    }

};

class ClientPerson:public Person
{
public:
    void setMediator(Mediator* mediator)
    {
        m_mediator = mediator;
    }
    void sendMessage(string msg)
    {
        m_mediator->sendMsg(this,msg);
    }
    void getMessage(string msg)
    {
        cout << "客户收到消息！" <<endl;
    }

};

接口使用

#include "mediator.h"

int main()
{
    HouseMediator *mediator = new HouseMediator();
    HostPerson *host = new HostPerson();
    host->setMediator(mediator);
    ClientPerson *client = new ClientPerson();
    client->setMediator(mediator);
    mediator->setClient(client);
    mediator->setHost(host);
    client->sendMessage("我要租房子!");
    host->sendMessage("有房子要出租!");

    return 0;
}

博客参照：

http://blog.csdn.net/wuzhekai1985/article/details/6673603