设计模式12——中介者模式

中介者模式中，个体与个体之间不需要发生直接关联，而是只需要与中介者进行交互，并由中介完成一系列任务。

Mediator.h内容

#ifndef Mediator_H_H
#define Mediator_H_H

#include <iostream>
using namespace std;

class Student;

class Mediator
{
public:
    Mediator() : src(NULL), target(NULL) {}
    void send(string strMessage);
    void setTarget(Student *target0) { target = target0; }

private:
    Student *src, *target;
};

class Student
{
public:
    Student() : mediator(NULL) {}
    virtual void recvMessage(string strMessage) = 0;
    virtual ~Student() {}
    void sendMessage(Student *student, string strMessage){
        mediator->setTarget(student);
        mediator->send(strMessage);
    }
    void setMediator(Mediator *mediator0) { mediator = mediator0; }

protected:
    Mediator *mediator;

};

class Student1 : public Student
{
public:
    virtual void recvMessage(string strMessage){
        cout << "Student1 recv: " << strMessage << endl;
    }
};

class Student2 : public Student
{
public:
    virtual void recvMessage(string strMessage){
        cout << "Student2 recv: " << strMessage << endl;
    }

};


void Mediator::send(string strMessage)
{
    target->recvMessage(strMessage);
}


void MediatorTest()
{
    Student *student1 = new Student1();
    Student *student2 = new Student2();
    Mediator *mediator = new Mediator();
    student1->setMediator(mediator);
    student2->setMediator(mediator);

    student1->sendMessage(student2, "How are you?");
    student2->sendMessage(student1, "Very well, Thank you!");

    delete mediator;

    delete student1;
    delete student2;

}


#endif

运行结果：

创建两个student，他们通过中介者实现了交互过程。