大话设计模式第七章---代理模式模式PHP实现

<?php
abstract class Subject {
    abstract public function request();
}

class Real_subject extends Subject {
    public function request() {
        echo "真实请求";
    }
}

class Proxy extends Subject {
    private $_real_subject = null;

    public function request() {
        if ($this->_real_subject == null) {
            $this->_real_subject = new Real_subject();
        }
        $this->_real_subject->request();
    }
}


$proxy = new Proxy();
$proxy->request();