WebSocketHandlerAdapter.java

    @Bean
    WebSocketHandlerAdapter getWebsocketHandlerAdapter(){


        HandshakeWebSocketService handshakeWebSocketService = new HandshakeWebSocketService();
        handshakeWebSocketService.setSessionAttributePredicate( k -> true);

        WebSocketHandlerAdapter wsha = new WebSocketHandlerAdapter(handshakeWebSocketService){
            @Override
            public Mono<HandlerResult> handle(ServerWebExchange exchange, Object handler) {

                Map<String, Object> attributes = exchange.getAttributes();
                
                exchange.getSession().subscribe((session) -> {
                    session.getAttributes().putAll(attributes);
                });

                return super.handle(exchange, handler);
            }
        };