SubscriptionEventListener listener = new SubscriptionEventListener() {
@Override
public void onEvent(String channelName, String eventName, String data) {
ExchangeEvent xevt = null;
try {
OrderBook snapshot = parseOrderBook(data);
xevt = new DefaultExchangeEvent(ExchangeEventType.SUBSCRIBE_ORDERS, data, snapshot);
} catch (IOException e) {
log.error("JSON stream error", e);