php工厂设计模式

class DbFactory {

    private $errmsg = '未找到类文件';

    static function factory($className){

        $className = strtoupper(substr($className,0,1)).substr($className, 1);

        if(include_once($className.'.php')){

            return new $className;

        }

        else{

            throw new Exception($this->errmsg);

        }

    }

}

DbFactory::factory('cars');

DbFactory::factory('animal');

Cars.php

<?php

class Cars{

    function __construct(){

        echo "汽车类";

    }

}

Animal.php

<?php

class Animal{

    function __construct(){

        echo '动物世界！';

    }

}