Spring websocket send to specific people

Question

I have added custom token based authentication for my spring-web app and extending the same for spring websocket as shown below

public class WebSocketConfig          


        

Answer 1

In your Websocket controller you should do something like this :

@Controller
public class GreetingController {

    @Autowired
    private SimpMessagingTemplate messagingTemplate;

    @MessageMapping("/hello")
    public void greeting(Principal principal, HelloMessage message) throws  Exception {
        Greeting greeting = new Greeting();
        greeting.setContent("Hello!");
        messagingTemplate.convertAndSendToUser(message.getToUser(), "/queue/reply", greeting);
    }
}

On the client side, your user should subscribe to topic /user/queue/reply.

You must also add some destination prefixes :

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.enableSimpleBroker("/topic", "/queue" ,"/user");
        config.setApplicationDestinationPrefixes("/app");
        config.setUserDestinationPrefix("/user");
    }
/*...*/
}

When your server receive a message on the /app/hello queue, it should send a message to the user in your dto. User must be equal to the user's principal.

I think the only problem in your code is that your "/user" is not in your destination prefixes. Your greetings messages are blocked because you sent them in a queue that begin with /user and this prefixe is not registered.

You can check the sources at git repo : https://github.com/simvetanylen/test-spring-websocket

Hope it works!

Answer 2

In my previous project I sent messages to one specific user; in detail I wrote the following:

CLIENT SIDE:

function stompConnect(notificationTmpl) 
{
    var socket = new SockJS('/comm-svr');
    stompClient = Stomp.over(socket);
    var theUserId 
    stompClient.connect({userId:theUserId}, function (frame) {
            debug('Connected: ' + frame);
            stompClient.subscribe('/topic/connect/'+theUserId, function (data)                   {
//Handle data
              } 
        });
}

SERVER SIDE

Spring websocket listener:

@Component
public class WebSocketSessionListener
{
    private static final Logger logger = LoggerFactory.getLogger(WebSocketSessionListener.class.getName());
    private List<String> connectedClientId = new ArrayList<String>();

    @EventListener
    public void connectionEstablished(SessionConnectedEvent sce)
    {
        MessageHeaders msgHeaders = sce.getMessage().getHeaders();
        Principal princ = (Principal) msgHeaders.get("simpUser");
        StompHeaderAccessor sha = StompHeaderAccessor.wrap(sce.getMessage());
        List<String> nativeHeaders = sha.getNativeHeader("userId");
        if( nativeHeaders != null )
        {
            String userId = nativeHeaders.get(0);
            connectedClientId.add(userId);
            if( logger.isDebugEnabled() )
            {
                logger.debug("Connessione websocket stabilita. ID Utente "+userId);
            }
        }
        else
        {
            String userId = princ.getName();
            connectedClientId.add(userId);
            if( logger.isDebugEnabled() )
            {
                logger.debug("Connessione websocket stabilita. ID Utente "+userId);
            }
        }
    }

    @EventListener
    public void webSockectDisconnect(SessionDisconnectEvent sde)
    {
        MessageHeaders msgHeaders = sde.getMessage().getHeaders();
        Principal princ = (Principal) msgHeaders.get("simpUser");
        StompHeaderAccessor sha = StompHeaderAccessor.wrap(sde.getMessage());
        List<String> nativeHeaders = sha.getNativeHeader("userId");
        if( nativeHeaders != null )
        {
            String userId = nativeHeaders.get(0);
            connectedClientId.remove(userId);
            if( logger.isDebugEnabled() )
            {
                logger.debug("Connessione websocket stabilita. ID Utente "+userId);
            }
        }
        else
        {
            String userId = princ.getName();
            connectedClientId.remove(userId);
            if( logger.isDebugEnabled() )
            {
                logger.debug("Connessione websocket stabilita. ID Utente "+userId);
            }
        }
    }

    public List<String> getConnectedClientId()
    {
        return connectedClientId;
    }
    public void setConnectedClientId(List<String> connectedClientId)
    {
        this.connectedClientId = connectedClientId;
    }
}

Spring websocket message sender:

@Autowired
    private SimpMessagingTemplate msgTmp;
    private void propagateDvcMsg( WebDeviceStatusInfo device )
    {
        String msg = "";
        String userId =((Principal)SecurityContextHolder.getContext().getAuthentication().getPrincipal()).getName()
        msgTmp.convertAndSend("/topic/connect"+userId, msg);
    }

I hope it's useful