Both ways are supported, but I recommend long polling method.

 private static TelegramBotsApi createSelfSignedTelegramBotsApi() throws TelegramApiException {
        return new TelegramBotsApi(BuildVars.pathToCertificateStore, BuildVars.certificateStorePassword, BuildVars.EXTERNALWEBHOOKURL, BuildVars.INTERNALWEBHOOKURL, BuildVars.pathToCertificatePublicKey);
    } 

String stringBuilder = "https://api.telegram.org/botxxx:ddddd_rrrrr/setwebhook?rl=https://vvvvv.ru:8443/yyy/page01";
System.out.println(stringBuilder);
URL url = new URL(stringBuilder);

HttpURLConnection con = (HttpURLConnection) url.openConnection();