trouble connecting to ServerSocket over the internet

Question

hello guys I've created a simple chat room app but I can't connect to server to send and receive data, here is part of my code:

server side:

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.regex.Pattern;

public class Listener {

public static void start() {
    try {
        final ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(true);
        serverSocketChannel.socket().bind(new InetSocketAddress(GetConfigs.getServerListenerPort()));
        final List<Operator> operators = new ArrayList<>();
        final int nOperators = 64;
        for (int i = 0; i < nOperators; i++) {
            operators.add(i, new Operator());
        }
        final int parallelism = Runtime.getRuntime().availableProcessors();
        ForkJoinPool pool = new ForkJoinPool(parallelism);
        pool.submit(() -> new Thread(() -> {
            int i = 0;
            while (true) {
                try {
                    operators.get(i).newOperation(serverSocketChannel.accept());
                    i++;
                    if (i == nOperators) {
                        i = 0;
                    }
                } catch (IOException ignored) {
                }
            }
        })).fork().invoke().start();
    } catch (IOException e) {
        Logging.log.error(e);
    }
}

client side :

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.regex.Pattern;

public class ConnectServer {

private static final String SERVER_ADDRESS = GetConfigs.getServerIPAddress();
private static final int SERVER_LISTENER_PORT = GetConfigs.getServerListenerPort();

private StringBuilder result = new StringBuilder();

private void connect() {
    result.delete(0, result.length());
    try {
        SocketChannel socketChannel = SocketChannel.open();
        socketChannel.configureBlocking(true);
        if (socketChannel.connect(new InetSocketAddress(InetAddress.getByName(SERVER_ADDRESS), SERVER_LISTENER_PORT))) {
            DataOutputStream dos = new DataOutputStream(socketChannel.socket().getOutputStream());
            DataInputStream dis = new DataInputStream(socketChannel.socket().getInputStream());
            dos.writeUTF("...");
            result.append(String.valueOf(dis.readUTF()));
            dos.close();
            dis.close();
            socketChannel.close();
        }
    } catch (IOException ex) {
        //...
    }
}

}

It does work on a LAN connection.

please help me...

Answer 1

Does the error appear in client or server application?

Maybe this could help you:

• Disable your firewall
• Check if any other application uses the port (maybe change port)
• Just an idea: Try it without lambda, it was just released and sometimes errors occur (e.g. in persistence)

Best regards