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

 1 #ifndef Mediator_H_H
 2 #define Mediator_H_H
 3 
 4 #include <iostream>
 5 using namespace std;
 6 
 7 class Student;
 8 
 9 class Mediator
10 {
11 public:
12     Mediator() : src(NULL), target(NULL) {}
13     void send(string strMessage);
14     void setTarget(Student *target0) { target = target0; }
15 
16 private:
17     Student *src, *target;
18 };
19 
20 class Student
21 {
22 public:
23     Student() : mediator(NULL) {}
24     virtual void recvMessage(string strMessage) = 0;
25     virtual ~Student() {}
26     void sendMessage(Student *student, string strMessage){
27         mediator->setTarget(student);
28         mediator->send(strMessage);
29     }
30     void setMediator(Mediator *mediator0) { mediator = mediator0; }
31 
32 protected:
33     Mediator *mediator;
34 
35 };
36 
37 class Student1 : public Student
38 {
39 public:
40     virtual void recvMessage(string strMessage){
41         cout << "Student1 recv: " << strMessage << endl;
42     }
43 };
44 
45 class Student2 : public Student
46 {
47 public:
48     virtual void recvMessage(string strMessage){
49         cout << "Student2 recv: " << strMessage << endl;
50     }
51 
52 };
53 
54 
55 void Mediator::send(string strMessage)
56 {
57     target->recvMessage(strMessage);
58 }
59 
60 
61 void MediatorTest()
62 {
63     Student *student1 = new Student1();
64     Student *student2 = new Student2();
65     Mediator *mediator = new Mediator();
66     student1->setMediator(mediator);
67     student2->setMediator(mediator);
68 
69     student1->sendMessage(student2, "How are you?");
70     student2->sendMessage(student1, "Very well, Thank you!");
71 
72     delete mediator;
73 
74     delete student1;
75     delete student2;
76 
77 }
78 
79 
80 #endif

运行结果：

创建两个student，他们通过中介者实现了交互过程。