PDD评论:需要登录，需要添加头信息
AccessToken $header[] = 'AccessToken:';

http://apiv4.yangkeduo.com/reviews/'.$goods_id.'/list?size=10&page='.$page
JD评论：
https://club.jd.com/comment/productPageComments.action?callback=fetchJSON_comment98&productId='.$goods_id.'&score='.$score.'&sortType='.$sortType.'&page='.$i.'&pageSize=10&isShadowSku=0&rid=0&fold=1
$sortType = 5;//排序
$score = 3;//0全部，1 差评，2中评，3好评，4带图评论，5追评

public function spider(){
        ini_set("display_errors", "On");//打开错误提示
        ini_set("error_reporting",E_ALL);//显示所有错误
        header("Content-Type: text/html; charset=utf-8");

        $header = $this->header();
        $header[] = 'Referer: https://item.jd.com/4995961.html';

       //设置浏览器信息
        $header[] = 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36';

        $url = 'https://club.jd.com/comment/productPageComments.action?callback=fetchJSON_comment98&productId=4995961&score=0&sortType=5&page=1&pageSize=10&isShadowSku=0&rid=0&fold=1';

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
    //为防止爬取多次禁用Ip，可用代理ip
//            curl_setopt($ch, CURLOPT_PROXY,'88.198.50.103'); //代理服务器地址
//            curl_setopt($ch, CURLOPT_PROXYPORT, '8080'); //代理服务器端口

        $output = curl_exec($ch);
        curl_close($ch);

        $encode = mb_detect_encoding($output, array("ASCII",'UTF-8',"GB2312","GBK",'BIG5'));
        if($encode == 'UTF-8'){
            echo $encode;
        }else{
            $output = mb_convert_encoding($output, 'UTF-8', $encode);
        }
        $result = json_decode($output, true);


}


//此函数提供了国内的IP地址
    public static function header(){
       $ip_long = array(
           array('607649792', '608174079'), //36.56.0.0-36.63.255.255
           array('1038614528', '1039007743'), //61.232.0.0-61.237.255.255
           array('1783627776', '1784676351'), //106.80.0.0-106.95.255.255
           array('2035023872', '2035154943'), //121.76.0.0-121.77.255.255
           array('2078801920', '2079064063'), //123.232.0.0-123.235.255.255
           array('-1950089216', '-1948778497'), //139.196.0.0-139.215.255.255
           array('-1425539072', '-1425014785'), //171.8.0.0-171.15.255.255
           array('-1236271104', '-1235419137'), //182.80.0.0-182.92.255.255
           array('-770113536', '-768606209'), //210.25.0.0-210.47.255.255
           array('-569376768', '-564133889'), //222.16.0.0-222.95.255.255
       );
       $rand_key = mt_rand(0, 9);
       $ip= long2ip(mt_rand($ip_long[$rand_key][0], $ip_long[$rand_key][1]));

        $headers['CLIENT-IP'] =$ip;
        $headers['X-FORWARDED-FOR'] =$ip;
        $headers["VIA"] = $ip;
        $headers["REMOTE_ADDR"] = $ip;

//        $header[] = 'Referer: https://item.jd.com/'.$goods_id.'.html';

       $headerArr = array();
       foreach($headers as $n => $v ) {
           $headerArr[] = $n .': ' . $v;
       }
       return $headerArr;
   }