[SOLVED] Kryonet Packet Recieving Issues

Newbie & Debugging Questions
#1

I’m just having a play around with Kryonet at the moment, trying to learn how it works and all that. Here’s my issue:

Whenever my client sends a packet, the server never tends to pick it up

ServerNetworkListener.java:


public class ServerNetworkListener extends Listener {
	public void connected(Connection c) {
		System.out.println("SOMEONE CAME IN :D");
	}
	
	public void disconnected(Connection c) {
		System.out.println("SOMEONE LEFT D:");
	}
	
	public void received(Connection c, Object o) {
		System.out.println("hit");
		if (o instanceof Packet) {
			Packet p = (Packet) o;
			if (o instanceof Packet001LoginToServer) {
				String user = ((Packet001LoginToServer)p).username;
				System.out.println(user + " logged in!");
			}
		}
	}
}

ClientMain.java:


public class ClientMain {
	private Client client;
	
	public ClientMain() {
		client = new Client();
		client.start();
		
		client.addListener(new ClientNetworkListener());
		
		Kryo k = client.getKryo();
		k.register(Packet001LoginToServer.class);
		
		try {
			client.connect(5000, InetAddress.getLocalHost(), 1234);
			client.sendTCP(new Packet001LoginToServer("LOLOLO"));
		} catch (Exception e) {
			e.printStackTrace();
			client.stop();
		}
		
//		String s = (String)JOptionPane.showInputDialog("Enter your username");
	}
	
	public static void main(String args[]) {
		new ClientMain();
	}
}

Here’s the output from the console:


SOMEONE CAME IN :D
SOMEONE LEFT D:

The connection to the server is clearly working, as the server outputs the text it should have output when a client connects, but it never outputs ‘hit’ or the username as I have coded it to.

Have I misunderstood here? Or is this just a bug in my network listener?

Thanks in advanced :smiley:

#2

would need to see where you instantiate the server class.

also krynet has some quirkyness.

dont forget to call client.start() and server.start() if you expect anything to work. :slight_smile:

(which you think might just be handled more seamlessly )

#3

Here is the server code:


public class ServerMain {
	private Server server;
	
	public ServerMain() throws IOException {
		server = new Server();
		registerPackets();
		server.addListener(new ServerNetworkListener());
		server.bind(1234);
		server.start();
		
		server.sendToAllTCP(new Packet001LoginToServer("LOLO"));
	}
	
	private void registerPackets() {
		Kryo kryo = server.getKryo();
		kryo.register(Packet001LoginToServer.class);
	}
	
	public static void main(String args[]) {
		Log.set(Log.LEVEL_DEBUG);
		try {
			new ServerMain();
			Log.set(Log.LEVEL_DEBUG);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
#4

Are you following a tutorial on YouTube? If you have, I’ve seen his tutorials and they are a little outdated, the code doesn’t run correctly because of changes in the library.

#5

Yes I am. I wasn’t aware they were outdated :frowning:

Could you point me in the direction of some tutorials that are more modern?

#6

Well, I think xSauceCode has some examples, but they aren’t super in depth :frowning: I haven’t looked much into Kryonet, but he sort of started me off, so I’d recommend him!

#7

Are your client and server packets not only the same, but separate classes?

#8

Did you try registering the packets before adding the Listener? I don’t know if this will fix it, but I think i had this problem before, and that was one of the things I did and it worked.

#9

So, for those of you interested, I found out the bug in the program.

The issue was, that I needed to give the Packet001LoginToServer class an empty constructor that took no parameters

EDIT

Another few key things to note that I have learnt from this is that the client will instantly quit if it isn’t manually given a game loop, so even using a

while (true) { }

statement, means that packets can be sent and received without it instantly quiting

Also, I seemed to find issue when using these following statements:


client.sendTCP(packet);
packet.sendTCP(packet);

A way to send packets across is using the connection parameter that is found in the listener like this:


public void connected(Connection c) {
	System.out.println(c.getRemoteAddressTCP() + " connected");
	c.sendTCP(new Packet001IdentificationRequest());``
}