"401 Unauthorized" while trying to view changes to Google Drive using the Java API

Question

Really stuck here. Code built on examples provided by Google:

public static void main(String[] args) {
    try {
        HttpTransport httpTransport = new NetHttpTransport();
        JsonFactory jsonFactory = new JacksonFactory();

    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            httpTransport, jsonFactory, CLIENT_ID, CLIENT_SECRET, Arrays.asList(DriveScopes.DRIVE))
            .setAccessType("online")
            .setApprovalPrompt("auto")
            .build();

    String url = flow.newAuthorizationUrl().setRedirectUri(REDIRECT_URI).build();
    System.out.println("Please open the following URL in your browser then type the authorization code:");
    System.out.println("  " + url);
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String code = br.readLine();

    GoogleTokenResponse response = flow.newTokenRequest(code).setRedirectUri(REDIRECT_URI).execute();
    GoogleCredential credential = new GoogleCredential().setFromTokenResponse(response);

    //Create a new authorized API client
    Drive service = new Drive.Builder(httpTransport, jsonFactory, credential).setApplicationName("Google Push").build();

    //Insert a file
    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");
    BufferedWriter bw = new BufferedWriter(new FileWriter(fileContent));
    bw.write("allo!!!!");
    bw.close();

    System.out.println("file created? -> " + fileContent.createNewFile());
    FileContent mediaContent = new FileContent("text/plain", fileContent);

    File file = service.files().insert(body, mediaContent).execute();
    System.out.println("File ID: " + file.getId());

    watchChange(service, "channelId", "web_hook", "https://clementlevallois.net/notifications"); // line 78

} catch (IOException ex) {
    Logger.getLogger(DriveCommandLine.class.getName()).log(Level.SEVERE, null, ex);
}

}

private static Channel watchChange(Drive service, String channelId, String channelType, String channelAddress) {

    Channel channel = new Channel();
    channel.setId(channelId);
    channel.setType(channelType);
    channel.setAddress(channelAddress);
    try {
        return service.changes().watch(channel).execute(); //line 91
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Stack trace:

com.google.api.client.googleapis.json.GoogleJsonResponseException: 401 Unauthorized
    at com.google.api.client.googleapis.json.GoogleJsonResponseException.from(GoogleJsonResponseException.java:145)
    at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:113)
    at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:40)
    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest$1.interceptResponse(AbstractGoogleClientRequest.java:312)
    at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:1049)
    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:410)
    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:343)
    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:460)
    at Controller.DriveCommandLine.watchChange(DriveCommandLine.java:91)
    at Controller.DriveCommandLine.main(DriveCommandLine.java:78)

Answer 1

The API returns an HTTP 401 or HTTP 403 response when invoking the Drive API. These errors may indicate any of:

Token expiration, Token cancellation (this will lead to the termination of the access token and update token) The token is not allowed for the required areas, the Request is not authorized correctly with the OAuth 2.0 protocol.

refreshToken(). " "

Answer 2

, :

- Google Apps, , API .

- URL-.

Answer 3

credential.getRequestInitializer() - null

101%

Userinfo Oauth2 API Google