CODEWITHSUNDEEP
javafile-iogoogle-drive-apigoogle-api-java-client
Sayo Oladeji
Sayo Oladeji

Reputation: 741

Reading directly from Google Drive in Java

Please I need to read the content of a file stored in Google Drive programmatically. I'm looking forward to some sort of
InputStream is = <drive_stuff>.read(fileID);
Any help? I'll also appreciate if I can write back to a file using some sort of

OutputStream dos = new DriveOutputStream(driveFileID);
dos.write(data);

If this sort of convenient approach is too much for what Drive can offer, please I'll like to have suggestions on how I can read/write to Drive directly from java.io.InputStream / OutputStream / Reader / Writer without creating temporary local file copies of the data I want to ship to drive. Thanks!

Upvotes: 3

Views: 15375

Answers (4)

V.Barod
V.Barod

Reputation: 51

// Build a new authorized API client service. Drive service = getDriveService();

    // Print the names and IDs for up to 10 files.
    FileList result = service.files().list()
         .setPageSize(10)
         .setFields("nextPageToken, files(id, name)")
         .execute();

    List<File> files = result.getFiles();
    if (files == null || files.size() == 0) {
        System.out.println("No files found.");
    } else {
        System.out.println("Files:");
        for (File file : files) {
            System.out.printf("%s (%s)\n", file.getName(), file.getId());
            String fileId = file.getId();

                Export s=service.files().export(fileId, "text/plain");
                InputStream in=s.executeMediaAsInputStream();
                InputStreamReader isr=new InputStreamReader(in);
                BufferedReader br = new BufferedReader(isr);
                String line = null;

                StringBuilder responseData = new StringBuilder();
                while((line = br.readLine()) != null) {
                    responseData.append(line);
                }
                System.out.println(responseData);
            } 
        }
    }

Upvotes: 1

jpllosa
jpllosa

Reputation: 2202

Using google-api-services-drive-v3-rev24-java-1.22.0:

To read the contents of a file, make sure you set DriveScopes.DRIVE_READONLY when you do GoogleAuthorizationCodeFlow.Builder(...) in your credential authorizing method/code.

You'll need the fileId of the file you want to read. You can do something like this:
FileList result = driveService.files().list().execute();
You can then iterate the result for the file and fileId you want to read.

Once you have done that, reading the contents would be something like this:

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
driveService.files().get(fileId).executeMediaAndDownloadTo(outputStream);
InputStream in = new ByteArrayInputStream(outputStream.toByteArray());

Upvotes: 0

pinoyyid
pinoyyid

Reputation: 22286

Here's a (incomplete) snippet from my app which might help.

            URL url = new URL(urlParam);
        HttpURLConnection connection = (HttpURLConnection) url
                .openConnection();
        connection.setDoOutput(true);
        connection.setRequestMethod("GET");
        connection
                .setRequestProperty("Authorization",
                        "OAuth "+accessToken);

        String docText = convertStreamToString(connection.getInputStream());

Upvotes: 0

Alain
Alain

Reputation: 6034

Please take a look at the DrEdit Java sample that is available on the Google Drive SDK documentation. This example shows how to authorize and build requests to read metadata, file's data and upload content to Google Drive.

Here is a code snippet showing how to use the ByteArrayContent to upload media to Google Drive stored in a byte array:

/**
 * Create a new file given a JSON representation, and return the JSON
 * representation of the created file.
 */
@Override
public void doPost(HttpServletRequest req, HttpServletResponse resp)
    throws IOException {
  Drive service = getDriveService(req, resp);
  ClientFile clientFile = new ClientFile(req.getReader());
  File file = clientFile.toFile();

  if (!clientFile.content.equals("")) {
    file = service.files().insert(file,
        ByteArrayContent.fromString(clientFile.mimeType, clientFile.content))
        .execute();
  } else {
    file = service.files().insert(file).execute();
  }

  resp.setContentType(JSON_MIMETYPE);
  resp.getWriter().print(new Gson().toJson(file.getId()).toString());
}

Upvotes: 0

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