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     * 处理数据
     * @access protected
     * @param  mixed $data 要处理的数据
     * @return mixed
     * @throws \Exception
     */
    protected function output($data)
    {
        if (!$this->isContent && !is_file($data)) {
            throw new Exception('file not exists:' . $data);
        }

        ob_end_clean();

        if (!empty($this->name)) {
            $name = $this->name;
        } else {
            $name = !$this->isContent ? pathinfo($data, PATHINFO_BASENAME) : '';
        }