Matlab中介者模式

Posted 2021-12-15 usaddew

中介者模式（Mediator Pattern）是用来降低多个对象和类之间的通信复杂性。这种模式提供了一个中介类，该类通常处理不同类之间的通信，并支持松耦合，使代码易于维护。想象一个乱糟糟的开发小组的工作状态，组员之间虽然在一起协同工作，但是意见难以统一，总是相互指挥，导致工作进度滞后。这时候，就需要一个仲裁者。所有的组员将自己的情况汇报给仲裁者，仲裁者会从团队的整体考虑，然后下达指令。仲裁者负责统一大家的意见。这样，团队的交流过程就变成了组员向仲裁者报告，仲裁者向组员下达指令的形式，而组员之间不再询问和沟通，这就是Mediator模式。

本文根据https://blog.csdn.net/niunai112/article/details/79913833所给的实例，用Matlab语言实现中介者模式

Mediator.m （抽象的中介者类）

classdef Mediator < handle 
    properties
        userlist = User.empty();
    end
    methods(Abstract)
        sendToAll(~,~);
        sendToPerson(~,~,~);
        join(~,~);
        leave(~,~);
    end
end

ChatPlatform.m （具体的中介者类，ConcreteMediator）

classdef ChatPlatform < Mediator
    methods
        function sendToAll(obj,msg)
           for i=1:length(obj.userlist)
               obj.userlist(i).accept(msg);
           end
        end
        function sendToPerson(obj,name,msg)
            user = obj.userlist([obj.userlist.name] == name);
            for i = 1:length(user)
                user.accept(msg);
            end
        end
        function join(obj,user)
            obj.userlist(end + 1) = user;
        end
        function leave(obj,user)
            obj.userlist = obj.userlist(obj.userlist ~= user);
        end
    end
end

User.m (抽象的同事类， Colleague)

classdef User < handle & matlab.mixin.Heterogeneous
    properties
        mediator
        name
    end
    
    methods
        function obj = User(name, mediator)
            obj.name = name;
            obj.mediator = mediator;
        end
        function sendToAll(obj,msg)
            obj.mediator.sendToAll(msg);
        end
        function sendToPerson(obj,name,msg)
            obj.mediator.sendToPerson(name,msg);
        end
        function join(obj)
            obj.mediator.join(obj);
        end
        function leave(obj)
            obj.mediator.leave(obj);
        end
    end
    methods(Abstract)    
        accept(~,~);
    end
end

NormalUser.m (具体的同事类， ConcreteColleague)

classdef NormalUser < User
    methods
        function obj = NormalUser(name, mediator)
            obj = [email protected](name, mediator);
        end      
        function accept(obj,msg)
            disp("[" + datestr(now) + "]" + obj.name + " accepted msg: " + msg);
        end
    end
end

测试代码：

chatPlatform = ChatPlatform();
a = NormalUser("A", chatPlatform);
b = NormalUser("B", chatPlatform);
c = NormalUser("C", chatPlatform);
a.join();
b.join();
c.join();
disp("-----------------A群发送消息------------------");
a.sendToAll("A：大家听得到吗?");
disp("-----------------A给B私发消息------------------");
a.sendToPerson("B", "A：B,我只想和你说");
disp("-----------------B给A私发消息------------------");
b.sendToPerson("A","B:可以，请说" );
disp("-----------------A离开聊天室------------------");
a.leave();
disp("-----------------B群发送消息------------------");
b.sendToAll("B:A能听到吗");

参考资料

https://www.runoob.com/design-pattern/mediator-pattern.html
https://blog.csdn.net/qq_39384184/article/details/80631275

https://blog.csdn.net/niunai112/article/details/79913833