Getting 401 Unauthorized from Google API Resumable Update - google-docs-api

Question

I am trying to integrate upload of arbitrary files to Google Docs into an existing application. This used to work before using resumable upload became mandatory. I am using Java client libraries.
The application is doing the upload in 2 steps:
- get the resourceId of the file
- upload the data
To get the resourceId I am uploading a 0-size file (i.e. Content-Length=0). I am passing ?convert=false in the resumable URL (i.e. https://docs.google.com/feeds/upload/create-session/default/private/full?convert=false).
I am passing "application/octet-stream" as content-type. This seems to work, though I do get different resourcesIds - "file:..." resourceIds for things like images, but "pdf:...." resourceIds for PDFs.
The second step constructs a URL based on the resourceId obtained previously and performs a search (getEntry). The URL is in the form of https://docs.google.com/feeds/default/private/full/file%3A.....
Once the entry is found the ResumableGDataFileUploader is used to update the content (0-byte file) with the actual data from the file being uploaded. This operation fails with 401 Unauthorized response when building ResumableGDataFileUploader instance.
I've tried with ?convert=false as well as ?new-revision=true and both of these at the same time. The result is the same.
The relevant piece of code:
MediaFileSource mediaFile = new MediaFileSource(
tempFile, "application/octet-stream");
final ResumableGDataFileUploader.Builder builder =
new ResumableGDataFileUploader.Builder(client, mediaFile, documentListEntry);
builder.executor(MoreExecutors.sameThreadExecutor());
builder.requestType(ResumableGDataFileUploader.RequestType.UPDATE);
// This is where it fails
final ResumableGDataFileUploader resumableGDataFileUploader = builder.build();
resumableGDataFileUploader.start();
return tempFile.length();
The "client" is an instance of DocsService, configured to use OAuth. It is used to find "documentListEntry" immediately before the given piece of code.
I had to explicitly specify request type, since it seems the client library code contains a bug causing NullPointerException for "update existing entry" case.
I have a suspicion that the issue is specifically in the sequence of actions (upload 0-byte file to get the resourceId, then update with actual file) but I can't figure out why it doesn't work.
Please help?

Answer 1

This code snippet works for me using OAuth 1.0 and OAuth 2.0:
static void uploadDocument(DocsService client) throws IOException, ServiceException,
InterruptedException {
ExecutorService executor = Executors.newFixedThreadPool(10);
File file = new File("<PATH/TO/FILE>");
String mimeType = DocumentListEntry.MediaType.fromFileName(file.getName()).getMimeType();
DocumentListEntry documentEntry = new DocumentListEntry();
documentEntry.setTitle(new PlainTextConstruct("<DOCUMENT TITLE>"));
int DEFAULT_CHUNK_SIZE = 2 * 512 * 1024;
ResumableGDataFileUploader.Builder builder =
new ResumableGDataFileUploader.Builder(
client,
new URL(
"https://docs.google.com/feeds/upload/create-session/default/private/full?convert=false"),
new MediaFileSource(file, mimeType), documentEntry).title(file.getName())
.requestType(RequestType.INSERT).chunkSize(DEFAULT_CHUNK_SIZE).executor(executor);
ResumableGDataFileUploader uploader = builder.build();
Future<ResponseMessage> msg = uploader.start();
while (!uploader.isDone()) {
try {
Thread.sleep(100);
} catch (InterruptedException ie) {
throw ie; // rethrow
}
}
DocumentListEntry uploadedEntry = uploader.getResponse(DocumentListEntry.class);
// Print the document's ID.
System.out.println(uploadedEntry.getId());
System.out.println("Upload is done!");
}