java - Gmail API : Credentials for Gmail API

Question

这是 "Java Quickstart" 中给出的代码Gmail API 教程。这是我需要为应用程序创建凭据的操作:

GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
    httpTransport, jsonFactory, clientSecrets, Arrays.asList(SCOPE))
    .setAccessType("online")
    .setApprovalPrompt("auto").build();

String url = flow.newAuthorizationUrl().setRedirectUri(GoogleOAuthConstants.OOB_REDIRECT_URI)
    .build();
System.out.println("Please open the following URL in your browser then type"
    + " the authorization code:\n" + url);

// Read code entered by user.
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String code = null;
try {
   code = br.readLine();
} catch (IOException e) {
   e.printStackTrace();
}

// Generate Credential using retrieved code.
GoogleTokenResponse response = null;
try {
   response = flow.newTokenRequest(code)
           .setRedirectUri(GoogleOAuthConstants.OOB_REDIRECT_URI).execute();
} catch (IOException e) {
   e.printStackTrace();
}
GoogleCredential credential = new GoogleCredential()
    .setFromTokenResponse(response);

我可以做些什么来自动执行上述过程，就像在此处完成的以获取凭据以供进一步使用一样？

以下示例适用于 Google Tasks。

GoogleAccountCredential credential =
   GoogleAccountCredential.usingOAuth2(this, Collections.singleton(TasksScopes.TASKS));

Answer 1

GoogleCredential credential = new GoogleCredential.Builder()
            .setTransport(httpTransport)
            .setJsonFactory(JSON_FACTORY)
            .setServiceAccountId(service_account)
            .setServiceAccountScopes(
                    Collections.singleton("https://mail.google.com/"))
            // .setServiceAccountPrivateKeyFromP12File(new
            // File(certLocation))
            .setServiceAccountPrivateKey(serviceAccountPrivateKey)
            .setServiceAccountUser(senderid).build();