import com.google.api.services.sheets.v4.SheetsScopes; //导入依赖的package包/类
private Sheets authorize() {
  try {
    InputStream in = new FileInputStream(new File(System.getenv("GOOGLE_OATH2_CREDENTIALS")));
    JsonFactory factory = new JacksonFactory();
    GoogleClientSecrets clientSecrets =
        GoogleClientSecrets.load(factory, new InputStreamReader(in, Charset.defaultCharset()));
    HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
    FileDataStoreFactory dataStoreFactory =
        new FileDataStoreFactory(new File(dataStoreDirectory));
    List<String> scopes = Collections.singletonList(SheetsScopes.SPREADSHEETS);
    GoogleAuthorizationCodeFlow flow =
        new GoogleAuthorizationCodeFlow.Builder(transport, factory, clientSecrets, scopes)
            .setAccessType("offline")
            .setDataStoreFactory(dataStoreFactory)
            .build();
    Credential credential =
        new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    return new Sheets.Builder(transport, factory, credential)
        .setApplicationName(APPLICATION_NAME)
        .build();
  } catch (Exception e) {
    return null;
  }
}