Mediator 中介者模式
GOOD：用一个中介对象来封装一系列的对象交互，中介者使各对象不需要显示的相互引用，从而降低耦合；而且可以独立地改变它们之间的交互。
例：
#include <iostream>
#include <string>
#include <vector>
using namespace std;
class Colleague;
//中介者类
class Mediator
{
public:
virtual void Send(string message,Colleague* col) = 0;
};
//抽象同事类
class Colleague
{
protected:
Mediator* mediator;
public:
Colleague(Mediator* temp)
{
mediator = temp;
}
};
//同事一
class Colleague1 : public Colleague
{
public:
Colleague1(Mediator* media) : Colleague(media){}
void Send(string strMessage)
{
mediator->Send(strMessage,this);
}
void Notify(string strMessage)
{
cout<<"同事一获得了消息"<<strMessage<<endl;
}
};
//同事二
class Colleague2 : public Colleague
{
public:
Colleague2(Mediator* media) : Colleague(media){}
void Send(string strMessage)
{
mediator->Send(strMessage,this);
}
void Notify(string strMessage)
{
cout<<"同事二获得了消息"<<strMessage<<endl;
}
};
//具体中介者类
class ConcreteMediator : public Mediator
{
public:
Colleague1 * col1;
Colleague2 * col2;
virtual void Send(string message,Colleague* col)
{
if(col == col1)
col2->Notify(message);
else
col1->Notify(message);
}
};
//客户端：
int main()
{
ConcreteMediator * m = new ConcreteMediator();
//让同事认识中介
Colleague1* col1 = new Colleague1(m);
Colleague2* col2 = new Colleague2(m);
//让中介认识具体的同事类
m->col1 = col1;
m->col2 = col2;
col1->Send("吃饭了吗？");
col2->Send("还没吃，你请吗？");
return 0;
}