在php中直接从Google Drive下载文件到服务器

Question

当任何用户从Google云端硬盘选择器中选择文件时，我想将文件从Google云端硬盘直接传输到我的服务器。我正在使用以下代码，但在使用以下代码时，文件无法下载到我的特定文件夹中。

回调功能：

function downloadFile(item) {
    var request = new XMLHttpRequest();
    var mimeType = item['mimeType'];
    if (typeof item.exportLinks != 'undefined') {
        if (mimeType == 'application/vnd.google-apps.spreadsheet') {
            mimeType = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
        }
        url = item['exportLinks'][mimeType];
        link = url;
    } else {
        lien = item['downloadUrl'].split("&");
        link = lien[0] + '&' + lien[1];
        url = item['downloadUrl'];
    }
    title = item['title'];
    type = mimeType;
    filesize = item['fileSize'];
    fileext = item['fileExtension'];
    id = item['id'];
    var datatable = [url, title, type, filesize, fileext,id];
    document.getElementById("myddlink").href=link; 
    request.open("POST", "downloadfile.php?" + datatable, true);
    request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    request.send("datatable=" + datatable);
}

下载文件的功能：

$upload_path='upload_folder';
    if (isset($_POST['exportFormat'])) {
            $pieces = explode(",", $_POST['exportFormat']);
            $url = $_POST['datatable'] . '&exportFormat=xlsx';
            $title = $pieces[1];
            $type = $pieces[2];
            $fileext = $pieces[0];
            $fileId = $pieces[5];
        }else {
            $url = $_POST['datatable'] . '&e=download';
            $pieces = explode(",", $_POST['gd']);
            $onlytitle = explode(".", $pieces[1]);
            $title = $onlytitle[0];
            $type = $pieces[2];
            $filesize = $pieces[3];
            $fileext = $pieces[4];
            $fileId = $pieces[5];
        }
        $fullPath = $upload_path . '/' . $title . '.' . $fileext;
        header("Pragma: public");
        header("Expires: 0");
        header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
        header("Cache-Control: public");
        header("Content-Description: File Transfer");
        header("Content-type: " . $type . "");
        header("Content-Disposition: attachment; filename=\"" . $title . '.' . $fileext . "\"");
        header("Content-Transfer-Encoding: binary");
        header("Content-Length: " . $filesize);
        // folder to save downloaded files to. must end with slash
        $destination_folder = $upload_path . '/';
        $newfname = $destination_folder . basename($title . '.' . $fileext);
        $file = fopen($url, "rb");
        if ($file) {
            $newf = fopen($newfname, "wb");
            if ($newf)
                while (!feof($file)) {
                    fwrite($newf, fread($file, 1024 * 8), 1024 * 8);
                }
        }
        if ($file) {
            fclose($file);
        }
        if ($newf) {
            fclose($newf);
        }
        ob_end_flush();

Php文件：

Get-WmiObject -query "select DeviceID,PNPDeviceID from Win32_SerialPort"