gistfile1.txt

@Override
    public Publisher<MutableHttpResponse<?>> doFilter(final HttpRequest<?> request, final ServerFilterChain chain) {
        if ( !isExcludedFromTokenExchange(request) ){
            final String exchangedToken = request.getHeaders().getAuthorization()
                    .map(keyCloakTokenExchangeService::exchangeToken)
                    .orElse(null);
            request.getHeaders.set(HttpHeaders.AUTHORIZATION, exchangedToken);
        }
        return chain.proceed(request);;
    }