Reactor, failed to load class "org.slf4j.impl.StaticLoggerBinder"

Question

I have started to play with Reactor but I'm having troubles with my first event :D

Following the example in github, I tried to write an "hello world" but without success...

What is the problem?

Code:

package reactor;

import static reactor.event.selector.Selectors.$;
import reactor.core.Environment;
import reactor.core.Reactor;
import reactor.core.spec.Reactors;
import reactor.event.Event;
import reactor.function.Consumer;

public class Main {

    public static void main(String[] args) {

        final Environment env = new Environment();

        final Reactor reactor = Reactors.reactor(env);

        String topic = "event.message";

        reactor.on($(topic), new Consumer<Event<Message>>(){

            @Override
            public void accept(Event<Message> t) {
                System.out.println("Hello World");
            }

        });

        final Message event = new Message();
        reactor.notify(topic, Event.wrap(event));
        System.out.println("ends");
    }

    public static class Message{

    }
}

Output:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
ends

Answer 1

Don't forget that Reactor is an implementation of Reactive Streams paradigm and everything there is async.

So, your reactor.notify(topic, Event.wrap(event)); is an event publishing to the EventRouter for some handler within separate Thread.

So, your main thead should wait until all downstream work will be done.

Or add Thread.sleep(1000); in the and of main or use CoutDownLatch to wait the event from that Reactor's thread (com.lmax.disruptor.RingBuffer by defult):

final CountDownLatch stopLatch = new CountDownLatch(1);

reactor.on($(topic), new Consumer<Event<Message>>(){

    @Override
    public void accept(Event<Message> t) {
        System.out.println("Hello World");
        stopLatch.countDown();
    }

});
....
stopLatch.await();