php curl 发送jso数据

php curl 发送jso数据代码如下：

class curl_data{
    public function send_data($url,$data){
        $httpheader = array('Content-type: application/json','Content-length:'.strlen($data)); #设置头
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch,CURLOPT_HTTPHEADER,$httpheader);
        $rs = curl_exec($ch);
        echo $rs;
        curl_close($ch);

    }
}

接收json数据使用：$GLOBALS['HTTP_RAW_POST_DATA'];