if (StringUtils.isBlank(clientId) || clientId.length() > 23) {
clientId = MqttClient.generateClientId();
}
String tmpDir = System.getProperty("java.io.tmpdir") + "/" + name;
MqttDefaultFilePersistence dataStore = new MqttDefaultFilePersistence(
tmpDir);
logger.debug(
"Creating new client for '{}' using id '{}' and file store '{}'",
url, clientId, tmpDir);
client = new MqttClient(url, clientId, dataStore);