php设计模式之简单工厂模式代码实例

<?php
header("Content-type:text/html;charset=utf-8");
/**
* 共同接口
*/
 interface db
{
    function conn();
}

/**
* mysql类
*/
class DbMysql implements db
{
    public function conn()
    {
        echo "连接上了mysql<br>";
    }
}

/**
* sqlite类
*/
class DbSqlite implements db
{
    public function conn()
    {
        echo "连接上了sqlite<br>";
    }
}

/**
*
*/
class Factory
{
    public static function createDb($type)
    {
        if ($type == 'mysql') {
            $db = new DbMysql();
            return $db->conn();
        }elseif ($type == 'sqlite') {
            $db = new DbSqlite();
            return $db->conn();
        }else{
            return 'err:不支持该类型的数据库连接';
        }
    }
}

echo Factory::createDb('mysql');
echo Factory::createDb('sqlite');