WebFlux - WebSocket Configuration.

ReactiveChatApplication.java

@Bean
public HandlerMapping webSocketMapping(UnicastProcessor<Event> eventPublisher, Flux<Event> events) {
    Map<String, Object> map = new HashMap<>();
    map.put("/websocket/chat", new ChatSocketHandler(eventPublisher, events));
    SimpleUrlHandlerMapping simpleUrlHandlerMapping = new SimpleUrlHandlerMapping();
    simpleUrlHandlerMapping.setUrlMap(map);

    simpleUrlHandlerMapping.setOrder(10);
    return simpleUrlHandlerMapping;
}