Stomp Client not always fetching data even if connection is established - websocket

Question

I am sending data from spring boot to client using stomp client and web socket. It is able to send data to the first user but as soon as user increases it is fetching data for only some users. This seems weird because its behavior should be same for all the users. I have found out after extensive researching that the reason for this is because i am connecting to a queue ('/user/queue') and have more than one client listening to it. How to avoid this problem or is it impossible to solve this issue.
My controller code-
#Controller
public class ScheduledUpdatesOnTopic {
#Autowired
public SimpMessageSendingOperations messagingTemplate;
#Autowired
private SimpMessagingTemplate template;
DateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
String json[][] = {{"Lokesh Gupta","34","India",df.format(date)},{"Meenal","23","Pakistan",df.format(date)},{"Gongo","12","Indonesia",df.format(date)},{"Abraham","17","US",df.format(date)},{"Saddam","56","Iraq",df.format(date)},{"Yimkov","67","Japan",df.format(date)},{"Salma","22","Pakistan",df.format(date)},{"Georgia","28","Russia",df.format(date)},{"Jaquline","31","Sri Lanka",df.format(date)},{"Chenchui","78","China",df.format(date)}};
String t[] = {"Lokesh Gupta","34","India","11/8/2017"};
String temp[][];
int p=0;
int count=0;
private MessageHeaderInitializer headerInitializer;
#MessageMapping("/hello")
public void start(SimpMessageHeaderAccessor accessor) throws Exception
{
String applicantId=accessor.getSessionId();
System.out.println("session id " + applicantId);
this.messagingTemplate.convertAndSendToUser(applicantId,"/queue/cache",json,createHeaders(applicantId));
}
private MessageHeaders createHeaders(String sessionId) {
SimpMessageHeaderAccessor headerAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.MESSAGE);
if (getHeaderInitializer() != null) {
getHeaderInitializer().initHeaders(headerAccessor);
}
headerAccessor.setSessionId(sessionId);
headerAccessor.setLeaveMutable(true);
return headerAccessor.getMessageHeaders();
}
public MessageHeaderInitializer getHeaderInitializer() {
return this.headerInitializer;
}
public void setHeaderInitializer(MessageHeaderInitializer headerInitializer) {
this.headerInitializer = headerInitializer;
}
And client side html is-
var socket = new SockJS('/gs-guide-websocket');
var stompClient = Stomp.over(socket);
stompClient.connect({ }, function(frame) {
console.log('Connected this ' + frame);
stompClient.subscribe("/user/queue/cache", function(data) {
// code to display this data..........
});
I have to use queue because that is the only way to send data to particular session ids. Any help will be appreciated !!

Answer 1

It sounds like you need to use the "Request-Reply" messaging pattern.
When the client connects to the server on the common queue, it includes a private return address. This return address can be used to generate a new private message queue name for use by the server and client exclusively (since they are the only 2 that know the private return address. The server can then send the client data over the private message queue.
The return address could be a random UUID for example, and the private queue name could be /queue/private. .
This "Request-Reply" messaging pattern is more formally explained here, among other useful messaging patterns:
http://www.enterpriseintegrationpatterns.com/patterns/messaging/ReturnAddress.html