Gmail Signature for entire organization - gmail

Question

I have used GmailQuickstart to modify email signatures. It updates my own gmail account, but I want o do that for all the users of the company.
How do I make my Google API project used be entire organization.
private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
// Load client secrets.
InputStream in = GmailQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));
// Build flow and trigger user authorization request.
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
.setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
.setAccessType("offline")
.build();
LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}
public static void main(String... args) throws IOException, GeneralSecurityException {
// Build a new authorized API client service.
final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
Gmail service = new Gmail.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
.setApplicationName(APPLICATION_NAME)
.build();
// Print the labels in the user's account.
String user = "me";
final java.util.logging.Logger buggyLogger = java.util.logging.Logger.getLogger(FileDataStoreFactory.class.getName());
buggyLogger.setLevel(java.util.logging.Level.SEVERE);
SendAs primaryAlias = null;
ListSendAsResponse aliases = service.users().settings().sendAs().list("me").execute();
for (SendAs alias : aliases.getSendAs()) {
if (alias.getIsPrimary()) {
primaryAlias = alias;
break;
}
}
//service.users().getProfile().getUserId();
SendAs aliasSettings = new SendAs()
.setSignature("Email : " + primaryAlias.getSendAsEmail() + "Company name, Address, zip");
SendAs result = service.users().settings().sendAs().patch(
"me",
primaryAlias.getSendAsEmail(),
aliasSettings)
.execute();
System.out.println("Updated signature for " + result.getDisplayName());
}
The above code works, I can change my email signatire. I would like to change email signature acress the comapony for all the users. Please Let me know if there is any solution that you guys have implemented?