中介者模式

【1】什么是中介者模式？

中介者模式：

【2】中介者模式代码示例：

代码示例：

#include<iostream>
#include <string>
using namespace std;

class Mediator;
class ConcreteColleague1;
class ConcreteColleague2;

class Colleague
{
protected:
    Mediator *mediator;
public:
    Colleague(Mediator *mediator)
    {
        this->mediator = mediator;
    }
};


class ConcreteColleague1 : public Colleague
{
public:
    ConcreteColleague1(Mediator *mediator) : Colleague(mediator)
    {}
    void send(string message);
    void notify(string message)
    {
        cout << "同事1得到消息: " << message << endl;
    }
};

class ConcreteColleague2 : public Colleague
{
public:
    ConcreteColleague2(Mediator *mediator) : Colleague(mediator)
    {}
    void send(string message);
    void notify(string message)
    {
        cout << "同事2得到消息: " << message << endl;
    }
};

class Mediator
{
public:
    virtual void send(string name, Colleague *colleague)=0;
};

class ConcreteMediator : public Mediator
{
public:
    ConcreteColleague1 *colleague1;
    ConcreteColleague2 *colleague2;
public:
    void send(string message, Colleague *colleague)
    {
        if (colleague == colleague1)
        {
            colleague2->notify(message);
        }
        else
        {
            colleague1->notify(message);
        }
    }
};

  
void ConcreteColleague1::send(string message) 
{
    mediator->send(message, this);
}

void ConcreteColleague2::send(string message) 
{
    mediator->send(message, this);
}

int main()
{
    ConcreteMediator *m = new ConcreteMediator();
    ConcreteColleague1 *c1 = new ConcreteColleague1(m);
    ConcreteColleague2 *c2 = new ConcreteColleague2(m);

    m->colleague1 = c1;
    m->colleague2 = c2;

    c1->send("吃饭啦");
    c2->send("去 ");

    return 0;
}
//Result:
/*
同事2得到消息: 吃饭啦
同事1得到消息: 去
*/

#include<iostream>
#include <string>
using namespace std;

class Country;

class UniteNations
{
public:
    virtual void declare(string message, Country *colleague) = 0;
}; 

class Country
{
protected:
    UniteNations *mediator;
public:
    Country(UniteNations *mediator)
    {
        this->mediator = mediator;
    }
};

class USA : public Country
{
public:
    USA(UniteNations *mediator) : Country(mediator)
    {}
    void declare(string message)
    {
        mediator->declare(message, this);
    }
    void getMessage(string message)
    {
        cout << "美国获得对方信息: " << message << endl;
    }
};

class Iraq : public Country
{
public:
    Iraq(UniteNations *mediator):Country(mediator)
    {}
    void declare(string message)
    {
        mediator->declare(message, this);
    }
    void getMessage(string message)
    {
        cout << "伊拉克获得对方信息: " << message << endl;
    }
};

class UnitedNationsSecurityCouncil:public UniteNations
{
public:
    USA *usa;
    Iraq *iraq;
    void declare(string message, Country *colleague)
    {
        if (colleague == usa)
        {
            iraq->getMessage(message);
        }
        else
        {
            usa->getMessage(message); 
        }
    }
};

int main()
{
    UnitedNationsSecurityCouncil *unsc = new UnitedNationsSecurityCouncil();
    
    USA *c1 = new USA(unsc);
    Iraq *c2 = new Iraq(unsc);

    unsc->usa = c1;
    unsc->iraq = c2;

    c1->declare("不准开发核武器，否则打你！");
    c2->declare("他妈的美国去死！");

    return 0;
}
//Result:
/*
伊拉克获得对方信息: 不准开发核武器，否则打你！
美国获得对方信息: 他妈的美国去死！
*/