void processMessage(String topic, MqttMessage msg) {
L.fine("Received " + msg + " to " + topic);
topic = topic.substring(topicPrefix.length(), topic.length());
if (topic.startsWith("set/")) processSetGet(topic.substring(4), msg, true);
else if (topic.startsWith("get/")) processSetGet(topic.substring(4), msg, false);
else L.warning("Ignored message " + msg + " to unknown topic " + topic);
}
