Exporting data to Google Spreadsheet from Google App Engine (Java version) - google-app-engine

Question

I am getting no where now. When I Google around to find a sample of "Exporting data to Google Spreadsheet from Google App Engine", I see a lot of Google Conversion API, Google Conversion API, Google Spreadsheet API and Google Docs API tutorials. But then they all deprecated from Google when I check at the Google site??? So, what is the most updated right now so I can make use of it?
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Okay now I use the Google Drive SDK via OAuth2 to create text file. But I have problem with this:
this is the error:
java.lang.NullPointerException at
java.net.URI$Parser.parse(URI.java:3004) at
java.net.URI.(URI.java:577) at
com.google.api.client.http.GenericUrl.(GenericUrl.java:100) at
com.google.api.client.googleapis.media.MediaHttpUploader.upload(MediaHttpUploader.java:269)
at
com.google.api.services.drive.Drive$Files$Insert.executeUnparsed(Drive.java:309)
at
com.google.api.services.drive.Drive$Files$Insert.execute(Drive.java:331)
at
com.company.dashboard.service.DriveService.initDoc(DriveService.java:84)
this is the code:
private GoogleCredential buildGoogleCredential(Credential credential) {
try {
logger.warning(oauth2Service.getClientCredential().toString());
GoogleCredential googleCredential = new GoogleCredential.Builder()
.setClientSecrets(oauth2Service.getClientCredential())
.setTransport(new NetHttpTransport())
.setJsonFactory(new JacksonFactory()).build();
googleCredential.setAccessToken(credential.getAccessToken());
googleCredential.setRefreshToken(credential.getRefreshToken());
return googleCredential;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private Drive buildService(GoogleCredential credential) {
return new Drive.Builder(new NetHttpTransport(), new JacksonFactory(), credential).build();
}
public void initDoc(HttpServletRequest req)
throws Exception {
User user = UserServiceFactory.getUserService().getCurrentUser();
Credential credential = oauth2Service.getStoredCredential(
user.getUserId(),
(CredentialStore)req.getSession().getServletContext().getAttribute(OAuth2Constant.GOOG_CREDENTIAL_STORE));
if (credential != null) {
logger.warning("Using access token: " + credential.getAccessToken());
try {
GoogleCredential googleCredential = buildGoogleCredential(credential);
Drive service = buildService(googleCredential);
if (service == null) {
logger.warning("very bad!");
}
File body = new File();
body.setTitle("My document");
body.setDescription("A test document");
body.setMimeType("text/plain");
java.io.File fileContent = new java.io.File("document.txt");
FileContent mediaContent = new FileContent("text/plain", fileContent);
service.files().insert(body, mediaContent).execute();
//File file = service.files().insert(body, mediaContent).execute();
//System.out.println("File ID: " + file.getId());
} catch (HttpResponseException e) {
if (e.getStatusCode() == 401) {
logger.warning(e.getMessage());
// Credentials have been revoked.
// TODO: Redirect the user to the authorization URL.
throw new UnsupportedOperationException();
}
} catch (IOException e) {
System.out.println("An error occurred: " + e);
}
}
oauth2Service.getClientCredential() returns (xxx = client id and client secret code, not shown in here)
{"web":{"client_id":"xxx.apps.googleusercontent.com","client_secret":"xxx"}}
This is my scope:
final static List<String> SCOPES = Arrays.asList("https://www.googleapis.com/auth/userinfo.profile",
"https://www.googleapis.com/auth/userinfo.email",
"https://www.googleapis.com/auth/drive",
"https://www.googleapis.com/auth/docs",
"https://www.googleapis.com/auth/drive.file");
final static String AUTH_RESOURCE_LOC = "/client_secrets.json";
final static String OATH_CALLBACK = "http://localhost:8888/oauth2callback";
This line
service.files().insert(body, mediaContent).execute();
throws NullPointerException. Any idea what had gone wrong???
P/S: Credential = com.google.api.client.auth.oauth2.Credential. I have my OAuth2 everything works good. I can retrieve user info without problem but not the Drive API. service is not null as you see I put it the log as "very bad" and it is not shown. No 401 exception is thrown means my Oauth2 is good with the scopes.
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DARN!!!! Finally solved the issue!!! My code was totally correct! Just I enabled the wrong API! It should be Drive API instead of Drive SDK API :/

Answer 1

You can generate a csv file from GAE and upload it using the Drive API with ?convert=true to have it automatically converted to a Google spreadsheet:
https://developers.google.com/drive/v2/reference/files/insert