<?php

interface SendMessage
{
 public function Send();
}

class RealSendMessage implements SendMessage
{
 public function Send()
 {
 echo '短信发送中...', PHP_EOL;
 }
}

class ProxySendMessage implements SendMessage
{
 private $realSendMessage;

 public function __construct($realSendMessage)
 {
 $this->realSendMessage = $realSendMessage;
 }

 public function Send()
 {
 echo '短信开始发送', PHP_EOL;
 $this->realSendMessage->Send();
 echo '短信结束发送', PHP_EOL;
 }
}

$sendMessage = new ProxySendMessage(new RealSendMessage());
$sendMessage->Send();