public function downLink($key)
    {
        $key = urlencode($key);
        $key = self::qiniuEscapequotes($key);
        $url = "http://{$this->domain}/{$key}";
        return $url;
    }
public function downLink($key)
    {
        $key = urlencode($key);
        $key = self::qiniuEscapequotes($key);
        $url = "http://{$this->domain}/{$key}";
        return $url;
    }
获取文件下载资源链接