Disallow broadcast in convertAndSendToUser method in SimpMessagingTemplate

Question

I am working with Spring websocket implementation. For sending a message to clients, there are two ways:

1) Using @SendToUser annotation
2) Using convertAndSendToUser method of SimpMessagingTemplate

@SendToUser takes a boolean parameter called broadcast which if set to false publishes the message to the current session. Is there a way I can have this behaviour in SimpMessagingTemplate.

Answer 1

If we take a look to the SendToMethodReturnValueHandler source code, we'll see:

if (broadcast) {
    this.messagingTemplate.convertAndSendToUser(user, destination, returnValue);
}
else {
    this.messagingTemplate.convertAndSendToUser(user, destination, returnValue, createHeaders(sessionId));
}

So, what you need for your use-case just use that overloaded convertAndSendToUser and provide a Map with `sessionId:

messagingTemplate.convertAndSendToUser(user, destination, payload, 
           Collections.singletonMap(SimpMessageHeaderAccessor.SESSION_ID_HEADER, sessionId))