protected function _parsePostData() {
        $postData = $this->getRequest()->getRawBody();
        if (!$postData) {
            return array();
        }
        try {
            $postData = Zend_Json::decode($postData);
        } catch (Zend_Json_Exception $e) {
            throw new Garp_Content_Api_Rest_Exception(
                sprintf(Garp_Content_Api_Rest::EXCEPTION_INVALID_JSON, $e->getMessage())
            );
        }
        return $postData;
    }