来自Google API的存储凭据可使用Java重复使用

Question

我已经成功授权了我的桌面应用程序。它存储一个名为的文件StoredCredential。为了不必在每次运行应用程序时都将URL复制到浏览器，接受等步骤，我想使用已经存储的凭据。

到目前为止，我的代码：

GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
    httpTransport,
    JSON_FACTORY,
    CLIENT_ID,
    CLIENT_SECRET,
    SCOPE)
    .setDataStoreFactory(dataStoreFactory)
    .setApprovalPrompt("auto").setAccessType("offline").build();
//
System.out.println("flow success");

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 tokenResponse
    = flow.newTokenRequest(code).setRedirectUri(REDIRECT_URI).execute();

GoogleCredential credential = new GoogleCredential
    .Builder()
    .setTransport(new NetHttpTransport())
    .setJsonFactory(new JacksonFactory())
    .setClientSecrets(CLIENT_ID, CLIENT_SECRET)
    .addRefreshListener(new CredentialRefreshListener() {
            @Override
            public void onTokenResponse(
                Credential credential,
                TokenResponse tokenResponse) throws IOException {

                System.out.println("Token Refreshed Succesfully");
            }

            @Override
            public void onTokenErrorResponse(
                Credential credential,
                TokenErrorResponse tokenErrorResponse) throws IOException {

                System.out.println("ERROR WITH TOKEN WTF?");
                }})
     .build();

如何读取存储的凭证并绕过命令行提示符？

我在想类似的东西：

if (stored cred exists) { 
    try  {
        // use 
    } catch  {
        // prompt the user
    }
}

Answer 1

您可以像这样从存储的凭据创建GoogleCredential对象：

GoogleCredential credential = new GoogleCredential.Builder()
        .setTransport(new NetHttpTransport())
        .setJsonFactory(new JacksonFactory())
        .setClientSecrets("client_id", "client_secret")
        .build();

credential.setAccessToken("access_token");