at present, the front end is disconnected in this way

/**
 * 
 *
 * @author rxliuli
 */
public abstract class BaseSessionEventListener<Event extends AbstractSubProtocolEvent> implements ApplicationListener<Event> {
    protected final Logger log = LoggerFactory.getLogger(getClass());
    @Autowired
    protected SocketSessionRegistry webAgentSessionRegistry;

    /**
     *  user id  session id 
     *
     * @param event      
     * @param biConsumer 
     */
    protected void using(Event event, BiConsumer<String, String> biConsumer) {
        StompHeaderAccessor sha = StompHeaderAccessor.wrap(event.getMessage());
        //login get from browser
        List<String> shaNativeHeader = sha.getNativeHeader("Authorization");
        String user = shaNativeHeader == null || shaNativeHeader.isEmpty() ? null : shaNativeHeader.get(0);
        //
        if (user == null || "".equals(user) || "undefined".equals(user) || "null".equals(user)) {
            user = SocketSessionRegistry.DIRECT_TOURIST;
        }
        String sessionId = sha.getSessionId();
        biConsumer.accept(user, sessionId);
    }
}

/**
 * Socket 
 *
 * @author rxliuli
 */
@Component
public class SessionDisconnectEventListener extends BaseSessionEventListener<SessionDisconnectEvent> {
    @Override
    public void onApplicationEvent(SessionDisconnectEvent event) {
        using(event, (user, sessionId) -> webAgentSessionRegistry.unregisterSessionId(user, sessionId));
    }
}

or our back-end value? (= ^ ^) y =