you can get all the client subscribed to a particular
destination using following code
MessageBroker msgBroker =
MessageBroker.getMessageBroker(null);
MessageService service =
(MessageService)msgBroker.getService("message-service");
AsyncMessage msg = new AsyncMessage();
msg.setDestination("destination");
String clientID = UUIDUtils.createUUID(false);
msg.setClientId(clientID);
msg.setMessageId(UUIDUtils.createUUID(false));
msg.setHeader("ID", new Long(leagueId).toString());
Set subscribers = service.getSubscriberIds(msg,
true);