中介者模式

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式的相互引用，从而使其耦合松散，而且可以独立地改变他们的交互<br />这个就真的式中介了，你租房，他出租，中介在两边调节，<br />代理类只是返回一个类，用于代理控制,而不是交互<br />中介类处理两个交互类的关系，互相调用需要交互的对象的方法，而对象只需要调用中介提供的接口就可以<br />实现了用户之间的耦合，使得用户之间不用维护关系，都交给中介类，但是不适宜太多用户，不然，中介类会太过臃肿

<?php
//抽象中介类
abstract class Mediator
{
    abstract public function Send($message, $colleague);
}
//中介实现类
class ConcreteMediator extends Mediator
{
    //需要联系操作的类
    public $colleague1;
    public $colleague2;
    //处理的方法，信息和当前的操作类
    public function Send($message, $colleague)
    {
        if ($colleague == $this->colleague1) {
            //执行对应类的处理方法
            $this->colleague2->Notify($message);
        } else {
            $this->colleague1->Notify($message);
        }
    }
}
//联系抽象类
abstract class Colleague
{
    protected $mediator;
    protected $name;
    public function __construct($mediator, $name)
    {
        $this->mediator = $mediator;
        $this->name = $name;
    }
}
//联系类A
class ConcreteColleagueA extends Colleague
{
    //发送消息
    public function Send(string $message)
    {
        $this->mediator->Send($this->name . "说：" . $message, $this);
    }
    //接受消息
    public function Notify(string $message)
    {
        echo $this->name . "得到信息：" . $message, PHP_EOL;
    }
}
//联系类B
class ConcreteColleagueB extends Colleague
{
    public function Send(string $message)
    {
        $this->mediator->Send($this->name . "说：" . $message, $this);
    }
    public function Notify(string $message)
    {
        echo $this->name . "得到信息：" . $message, PHP_EOL;
    }
}
//实例化中介类
$ConcreteMediator = new ConcreteMediator();
//联系类
$ConcreteColleagueA = new ConcreteColleagueA($ConcreteMediator, '天天');
$ConcreteColleagueB = new ConcreteColleagueB($ConcreteMediator, '小明');
//中介类对应关系
$ConcreteMediator->colleague1=$ConcreteColleagueA;
$ConcreteMediator->colleague2=$ConcreteColleagueB;
//联系
$ConcreteColleagueA->Send('你在哪呢，还不回来');
$ConcreteColleagueA->Send('再不回来，没肉吃了');
$ConcreteColleagueB->Send('等我，马上');