如何在Spring Reactive Websocket API中广播消息？

import org.springframework.stereotype.Component;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import org.springframework.web.reactive.socket.WebSocketSession;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.core.publisher.Sinks;

@Component
public class MyWebSocketHandler implements WebSocketHandler {

    private final Sinks.Many<String> sink;

    public MyWebSocketHandler() {
        this.sink = Sinks.many().multicast().onBackpressureBuffer();
    }

    public Flux<String> getBroadcast() {
        return sink.asFlux();
    }

    @Override
    public Mono<Void> handle(WebSocketSession session) {
        Flux<WebSocketMessage> messageFlux = session.receive()
                .doOnNext(message -> {
                    String payload = message.getPayloadAsText();
                    sink.tryEmitNext(payload); // 将接收到的消息发送到广播流
                });

        Mono<Void> output = session.send(getBroadcast().map(session::textMessage));

        return Mono.zip(messageFlux, output).then();
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.reactive.handler.WebSocketHandlerAdapter;
import org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter;

@RestController
@RequestMapping("/websocket")
public class MyController {

    private final MyWebSocketHandler webSocketHandler;

    @Autowired
    public MyController(MyWebSocketHandler webSocketHandler) {
        this.webSocketHandler = webSocketHandler;
    }

    @GetMapping(produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<String> getBroadcast() {
        return webSocketHandler.getBroadcast();
    }

    @Bean
    public WebSocketHandlerAdapter webSocketHandlerAdapter() {
        return new WebSocketHandlerAdapter();
    }
}