curl使用，發送json格式

//curl
    function http($url, $data = NULL, $json = false)
    {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        if (!empty($data)) {

            if($json && is_array($data)){
                $data = json_encode( $data );
            }
            curl_setopt($curl, CURLOPT_POST, 1);
            curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            if($json){ //發送JSON數據
                curl_setopt($curl, CURLOPT_HEADER, 0);
                curl_setopt($curl, CURLOPT_HTTPHEADER,
                    array(
                        'Content-Type: application/json; charset=utf-8',
                        'Content-Length:' . strlen($data))
                );
            }
        }
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        $res = curl_exec($curl);
        $errorno = curl_error($curl);
        if ($errorno) {
            return array('errorno' => false, 'errmsg' => $errorno);
        }
        curl_close($curl);
        return json_decode($res, true);
    }