php实现设计模式之 中介者模式

<?php 

/*

 * 中介者模式：用一个中介对象来封装一系列的对象交互,使各对象不需要显式地相互引用从而使其耦合松散,而且可以独立地改变它们之间的交互

 */



/*

 * 以一个同学qq群为例说明，qq作为中介者，同学作为相互交互的对象

 */



//抽象中介者，利用中介发送消息

abstract class Mediator{

	abstract function send($message,$user);

}



//抽象同事类，利用中介发送消息

abstract class Colleague{

	private $mediator;

	

	public function __construct($mediator){

		$this->mediator = $mediator;

	}

	

	public function send($message){

		$this->mediator->send($message,$this);

	}

	

	abstract function notify($message);

}



//具体的同事类a b c d e

class StuA extends Colleague{

	public function notify($message){

		echo 'Stu A says: '.$message;

		echo "<br/>";

	}

}



class StuB extends Colleague{

	public function notify($message){

		echo 'Stu B says: '.$message;

		echo "<br/>";

	}

}



class StuC extends Colleague{

	public function notify($message){

		echo 'Stu C says: '.$message;

		echo "<br/>";

	}

}



class StuD extends Colleague{

	public function notify($message){

		echo 'Stu D says: '.$message;

		echo "<br/>";

	}

}



class StuE extends Colleague{

	public function notify($message){

		echo 'Stu E says: '.$message;

		echo "<br/>";

	}

}



//具体的中介者

class QQ extends Mediator{

	public $users = array();

	

	public function setUsers($user){//把对象添加进来

		$this->users[] = $user;

	}

	

	public function send($message, $user){//推送消息

		for($i=0;$i<count($this->users);$i++){

			if($user == $this->users[$i]){

				$this->users[$i]->notify($message);

			}

		}

	}

}



class Client{

	public static function main(){

		//流程：先建立中介者

		$qq = new QQ();

		//实例化交互对象

		$stu_a = new StuA($qq);

		$stu_b = new StuB($qq);

		$stu_c = new StuC($qq);

		$stu_d = new StuD($qq);

		$stu_e = new StuE($qq);

		//把对象加入中介者

		$qq->setUsers($stu_b);

		$qq->setUsers($stu_a);

		$qq->setUsers($stu_c);

		$qq->setUsers($stu_d);

		$qq->setUsers($stu_e);

		

		//交流

		$stu_a->send('昨天点名了吗，各位大神');

		$stu_c->send('难道你没去');

		$stu_a->send('是啊');

		$stu_b->send('恭喜你中奖了');

		$stu_d->send('恭喜你中奖了');

		$stu_e->send('恭喜你中奖了');

		$stu_a->send('我去');

	}

}



Client::main();

?>

　　UML类图如下