Async IO Real-time infrastructure for the JVM.

@ManagedService(path = "/atmosphere/chat")
public class ChatEndpoint {

    @Ready
    public void onReady(AtmosphereResource r) {
        r.getBroadcaster().broadcast(
            r.uuid() + " joined");
    }

    @Message(decoders = {JacksonDecoder.class})
    public ChatMessage onMessage(ChatMessage msg) {
        return msg; // broadcast to all
    }

    @Disconnect
    public void onDisconnect(AtmosphereResourceEvent e) {
        e.broadcaster().broadcast(
            e.getResource().uuid() + " left");
    }
}

import { useAtmosphere } from 'atmosphere.js/react';

export default function Chat() {
  const { data, push, state } = useAtmosphere({
    request: {
      url: '/atmosphere/chat',
      transport: 'websocket',
    },
  });

  const send = (text) =>
    push({ author: 'me', text });

  return (
    <div>
      <p>{state} — {data?.text}</p>
      <button onClick={() => send('Hello!')}>Send</button>
    </div>
  );
}