// Be notified if a new server joins the cluster.
// Print all the known servers and the only the ones that were discovered.
nc, err := nats.Connect("demo.nats.io",
	nats.DiscoveredServersHandler(func(nc *nats.Conn) {
		log.Printf("Known servers: %v\n", nc.Servers())
		log.Printf("Discovered servers: %v\n", nc.DiscoveredServers())
	}))
if err != nil {
	log.Fatal(err)
}
defer nc.Close()

// Do something with the connection

class ServersAddedListener implements ConnectionListener {
    public void connectionEvent(Connection nc, Events event) {
        if (event == Events.DISCOVERED_SERVERS) {
            for (String server : nc.getServers()) {
                System.out.println("Known server: "+server);
            }
        }
    }
}

public class ListenForNewServers {
    public static void main(String[] args) {

        try {
            Options options = new Options.Builder().
                                        server("nats://demo.nats.io:4222").
                                        connectionListener(new ServersAddedListener()). // Set the listener
                                        build();
            Connection nc = Nats.connect(options);

            // Do something with the connection

            nc.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

let nc = NATS.connect("nats://demo.nats.io:4222");
nc.on('serversDiscovered', (urls) => {
    t.log('serversDiscovered', urls);
});

# Asyncio NATS client does not support discovered servers handler right now

# The Ruby NATS client does not support discovered servers handler right now

nc.on('serversChanged', (ce) => {
    t.log('servers changed\n', 'added: ',ce.added, 'removed:', ce.removed);
});