<?php

  //桥接模式

  abstract class info{

       protected $send=null;

       public function __construct($send){

           $this->send=$send;

       }

        abstract public function msg($content);

     public function send($to,$content){

          $content=$this->msg($content);

          $this->send->send($to,$content);

     }

 }

 class zn{

      public function send($to,$content){

         echo '站内信给',$to,'<br>','内容是',$content;

      }

 }

 class email{

     public function send($to,$content){

        echo 'email给',$to,'<br>','内容是',$content;

     }

 }

  class sms{

     public function send($to,$content){

        echo 'sms给',$to,'<br>','内容是',$content;

     }

 }

 class commoninfo extends info{

      public function msg($content){

            return '普通'.$content;

      }

 }

  class warninfo extends info{

      public function msg($content){

            return '紧急'.$content;

      }

 }

  class dangerinfo extends info{

      public function msg($content){

            return '特急'.$content;

      }

 }

 //用站内信发普通信息

 $commoninfo=new commoninfo(new zn());

 $commoninfo->send('小明','该去吃饭了');

 //用手机发送特急信息

 $dangerinfo=new dangerinfo(new sms());

 $dangerinfo->send('小刚','紧急回家');