I cannot get the file with short-lived URL (downloadUrl) from Google Drive API

问题

I have problem on getting files from downloadUrl provided from Google Drive API v2.

Here is the screenshot.

I have tried several websites and it still occurs. How can I fix it? Or is it a problem from Google?

20200312 Edit: I am using Javascript for Google File Picker and it returns JSON for the picked file. Then I use Classic ASP to get the file to server and save.

Here is the code

Front-end

function initGooglePicker() {
    var picker = new FilePicker({
        apiKey: API_KEY,
        clientId: CLIENT_ID,
        buttonEl: document.getElementById('btnGoogleDrive'),
        onSelect: function(file, access_token) {
            var path, ext, filename;
            if (file.downloadUrl) {
                path = file.downloadUrl;
                filename = file.title;
                ext = filename.split('.').pop().toLowerCase();
            }
            else if (file.exportLinks) {
                if (file['exportLinks']['application/pdf']) {
                    path = file['exportLinks']['application/pdf'] + "&exportFormat=pdf" ;
                    ext = "pdf";
                    filename = file.title + "." + ext;
                }
            }
            $('#access_token').val(access_token);
        },
        onCancel: function() {}
    });
}

Back-end

Function UploadGoogleDriveFile(fromPath, toPath, accessToken)
    Dim retVal
    retVal = "0"
    Dim objXML
    Set objXML = Server.CreateObject("MSXML2.ServerXMLHTTP")
    objXML.Open "GET", fromPath, False
    objXml.SetRequestHeader "Authorization", "Bearer " & accessToken
    objXML.Send
    If objXML.readystate = 4 Then
        Response.Write(objXML.status & "<br>")
        Response.Write(objXML.responseBody)
        Response.End
    End If
    If objXML.readystate = 4 And objXML.status = 200 Then
        If Len(objXML.responseText) > acct_cv_file_size Then
            retVal = "2"
        Else
            CreateFolderBeforeUpload(toPath)
            Set objStream = Server.createobject("Adodb.Stream")
            objStream.Type = 1
            objStream.Open
            objStream.Write objXML.responseBody
            objStream.SaveToFile toPath, 2
            objStream.Close
            Set objStream = Nothing
            retVal = "1"
        End If
    End If
    Set objXML = Nothing
    UploadGoogleDriveFile = retVal
End Function

回答1:

If you want to download a file using the Drive API V2 and setting the access token in the header, you have to do it by calling this url:

https://www.googleapis.com/drive/v2/files/[file-Id]?alt=media

As it's told in the Response section in the Files: get endpoint. It's really important the url parameter alt=media in order to make it work.

I've used this code before (works for me), which I found on Issue Tracker, in that way you can have another approach, too.

//fileurl - https://www.googleapis.com/drive/v2/files/[file-Id]?alt=media
//accessToken - client's accessToken 
//filepath - location to store the downloaded file

public void downloadGdriveFileThroughWebRequest(string fileurl, string filepath, string accessToken)
        {
            HttpWebRequest rq = (HttpWebRequest)WebRequest.Create(fileurl);
            rq.Method = "GET";
            rq.PreAuthenticate = true;
            rq.Headers.Add("Authorization", "Bearer " + accessToken);
            try { 
            HttpWebResponse resp = (HttpWebResponse)rq.GetResponse();
            using (Stream output = File.OpenWrite(filepath))
            {
                using (Stream s = resp.GetResponseStream())
                {
                    byte[] buffer = new byte[8192];
                    int bytesRead;
                    while ((bytesRead = s.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        output.Write(buffer, 0, bytesRead);
                    }
                }
            }
            }

            catch (WebException ex)
            {
                using (var stream = ex.Response.GetResponseStream())
                using (var reader = new StreamReader(stream))
                {
                    reader.ReadLine();
                    Console.WriteLine(reader.ReadToEnd());
                }
            }
        }

来源：https://stackoverflow.com/questions/60595512/i-cannot-get-the-file-with-short-lived-url-downloadurl-from-google-drive-api

标签

google-drive-api