Why in multiple connections to PricesResource Publisher, only one gets the stream?

问题

It seems that only one http client gets the stream of data, while the others do not.

Is it true that the Publisher is hot data, and that it should broadcast to all subscribers?

Please find more in Can I allow multiple http clients to consume a Flowable stream of data with resteasy-rxjava2 / quarkus?

package org.acme.kafka;

import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import io.reactivex.Flowable;
import io.reactivex.Observable;
import org.jboss.resteasy.annotations.SseElementType;
import org.reactivestreams.Publisher;

import io.smallrye.reactive.messaging.annotations.Channel;

import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

import static io.reactivex.Flowable.fromIterable;

/**
 * A simple resource retrieving the "in-memory" "my-data-stream" and sending the items to a server sent event.
 */
@Path("/migrations")
public class StreamingResource {
    private volatile Map<String, String> counterBySystemDate = new ConcurrentHashMap<>();

    @Inject
    @Channel("migrations")
    Flowable<String> counters;

    @GET
    @Path("/stream")
    @Produces(MediaType.SERVER_SENT_EVENTS) // denotes that server side events (SSE) will be produced
    @SseElementType("text/plain") // denotes that the contained data, within this SSE, is just regular text/plain data
    public Publisher<String> stream() {
        Flowable<String> mainStream = counters.doOnNext(dateSystemToCount -> {
            String key = dateSystemToCount.substring(0, dateSystemToCount.lastIndexOf("_"));
            counterBySystemDate.put(key, dateSystemToCount);
        });
        return fromIterable(counterBySystemDate.values().stream().sorted().collect(Collectors.toList()))
                .concatWith(mainStream)
                .onBackpressureLatest();
    }
}

回答1:

You may use Replay operator or ConnectableObservable

回答2:

What I did then was to inject the messages coming on the Flowable into a PublishSubject pipe and apply a backpressure strategy, thus offering a broadcast downstream.

来源：https://stackoverflow.com/questions/61876986/why-in-multiple-connections-to-pricesresource-publisher-only-one-gets-the-strea

标签

jax-rs

rx-java

rx-java2

resteasy

quarkus