EventReceived Callback never invoked

[KIC]

By following the Sampe code I try to connect a Spring (Java) server using server sent events. The URL works fine using curl but with EventSource4Net the EventReceived handler is never invoked.

using EventSource4Net;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using slf4net;
using slf4net.Resolvers;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("start ...");

            try
            {
                
                CancellationTokenSource cts = new CancellationTokenSource();
                EventSource es = new EventSource(new Uri("http://localhost:9999/bus/api/v1/subscribe/karli"), 50000);
                es.StateChanged += new EventHandler<StateChangedEventArgs>((o, e) => { Console.WriteLine("New state: " + e.State.ToString()); });
                es.EventReceived += new EventHandler<ServerSentEventReceivedEventArgs>((o, e) => { Console.WriteLine("--------- Msg received -----------\n" + e.Message.ToString()); });
                es.Start(cts.Token);
                Console.WriteLine("EventSource started");

                var a = Console.Read();
                cts.Cancel();
            }
            catch (Exception ex)
            {
                Console.WriteLine("dasda {0}", ex);
            }
        }

        private static void OnMessage(ServerEventMessage message)
        {
            Console.WriteLine($"OnMessage {message}");
        }
       
    }
}

prints:

start ...
slf4net: The factory resolver AppConfigFactoryResolver returned null from GetFactory().  The fallback no operation logger factory will be used instead.


Application information:
    Application domain: ConsoleApplication1.vshost.exe
    Application path: C:\Users\xxx\documents\visual studio 2015\Projects\ConsoleApplication1\ConsoleApplication1\bin\Debug\
    Machine name: XXX
EventSource started
New state: CONNECTING
New state: OPEN

After that nothing happens while I would expect the "--------- Msg received -----------\n" + e.Message.ToString()); to be printed as events are being sent

$ curl "http://localhost:9999/bus/api/v1/subscribe/karli" -v
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 9999 (#0)
> GET /bus/api/v1/subscribe/karli HTTP/1.1
> Host: localhost:9999
> User-Agent: curl/7.47.0
> Accept: */*
>
< HTTP/1.1 200
< Content-Type: application/stream+json
< Transfer-Encoding: chunked
< Date: Thu, 28 Jun 2018 05:00:01 GMT
<
{"key":"1","offset":3,"value":{}}

[KIC]

It seems like EventSource4Net is only supporting "text/event-stream" media type. It would be nice to support json stream as well.