Web 应用程序部署不生成授权令牌

Question

I'm trying send using gmail api with oauth2 credentials like below

private Credential getCredentials(NetHttpTransport httpTransport) throws IOException {
        // Load client secrets.
        try {
            Resource file = resourceLoader.getResource("classpath:credentials.json");
            InputStream inputStream = file.getInputStream();
            GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
                    new InputStreamReader(inputStream));
            // Build flow and trigger user authorization request.
            GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(httpTransport, JSON_FACTORY,
                    clientSecrets, SCOPES)
                            .setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
                            .setAccessType("offline").build();

            return new AuthorizationCodeInstalledApp(flow,  new LocalServerReceiver()).authorize("user");
        } catch (Exception exception) {
            exception.printStackTrace();
            LOGGER.info("Exception occured:: {}", exception.getMessage());
            throw new RecordNotFoundException(exception.getMessage());
        }

    }

using desktop app's credentials.json file.

When I have deployed in dev server I am unable to generate access and refresh token saved file.

Could you please help me.

Answer 1

AuthorizationCodeInstalledApp OAuth 2.0 authorization code flow for an installed Java application that persists end-user credentials.

You cant deploy that to a server its going to open the authorization window on the server.

For a web application it looks like you should be following this Oauth

public class CalendarServletSample extends AbstractAuthorizationCodeServlet {

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws IOException {
    // do stuff
  }

  @Override
  protected String getRedirectUri(HttpServletRequest req) throws ServletException, IOException {
    GenericUrl url = new GenericUrl(req.getRequestURL().toString());
    url.setRawPath("/oauth2callback");
    return url.build();
  }

  @Override
  protected AuthorizationCodeFlow initializeFlow() throws IOException {
    return new GoogleAuthorizationCodeFlow.Builder(
        new NetHttpTransport(), JacksonFactory.getDefaultInstance(),
        "[[ENTER YOUR CLIENT ID]]", "[[ENTER YOUR CLIENT SECRET]]",
        Collections.singleton(CalendarScopes.CALENDAR)).setDataStoreFactory(
        DATA_STORE_FACTORY).setAccessType("offline").build();
  }

  @Override
  protected String getUserId(HttpServletRequest req) throws ServletException, IOException {
    // return user ID
  }
}

public class CalendarServletCallbackSample extends AbstractAuthorizationCodeCallbackServlet {

  @Override
  protected void onSuccess(HttpServletRequest req, HttpServletResponse resp, Credential credential)
      throws ServletException, IOException {
    resp.sendRedirect("/");
  }

  @Override
  protected void onError(
      HttpServletRequest req, HttpServletResponse resp, AuthorizationCodeResponseUrl errorResponse)
      throws ServletException, IOException {
    // handle error
  }

  @Override
  protected String getRedirectUri(HttpServletRequest req) throws ServletException, IOException {
    GenericUrl url = new GenericUrl(req.getRequestURL().toString());
    url.setRawPath("/oauth2callback");
    return url.build();
  }

  @Override
  protected AuthorizationCodeFlow initializeFlow() throws IOException {
    return new GoogleAuthorizationCodeFlow.Builder(
        new NetHttpTransport(), JacksonFactory.getDefaultInstance()
        "[[ENTER YOUR CLIENT ID]]", "[[ENTER YOUR CLIENT SECRET]]",
        Collections.singleton(CalendarScopes.CALENDAR)).setDataStoreFactory(
        DATA_STORE_FACTORY).setAccessType("offline").build();
  }

  @Override
  protected String getUserId(HttpServletRequest req) throws ServletException, IOException {
    // return user ID
  }
}

Answer 2

From what I have understood from your question and comments you want to achieve the following:

With your current code send email messages from your application which already works on your local machine and now you want to do it too in a web server.

Considering that you are the only user that needs to authorise the application you can achieve what you are aiming using service accounts .

A service account works best for applications like yours where you don't need authorization from your users but rather from your account to for example send emails automatically.

These type of accounts belong to your application rather than to an individual user and can make API requests without the need to authorise through the UI. This guide from the documentation will walk you step through step on how to set up your authorization with service accounts.

Moreover, bare in mind that in order for the service account to execute requests in your name (as you need an user to send emails) you should use domain-wide authorization so that the service account can make such requests in the name of the user. Also note that you need a Google Workspace account to implement domain wide authorization (let me know if you don't have it as I can propose a workaround) .