NodeClient.java

import java.io.*;
import java.net.Socket;
import java.util.Random;
import java.util.concurrent.atomic.AtomicInteger;

public class NodeClient {

    private static final String HOST              = "localhost";
    private static final int    PORT              = 5001;
    private static final int    DEFAULT_ORDERS    = 10;

    public static void main(String[] args) throws IOException, InterruptedException {

        String nodeName  = args.length > 0 ? args[0] : "Node-?";
        int    numOrders = args.length > 1 ? Integer.parseInt(args[1]) : DEFAULT_ORDERS;

        System.out.printf("[%s] Connecting to %s:%d...%n", nodeName, HOST, PORT);

        try (Socket             socket = new Socket(HOST, PORT);
             ObjectOutputStream out    = new ObjectOutputStream(socket.getOutputStream())) {

            System.out.printf("[%s] Connected. Sending %,d orders...%n", nodeName, numOrders);

            Random        random    = new Random();
            AtomicInteger idCounter = new AtomicInteger(1);

            for (int i = 0; i < numOrders; i++) {
                int   seqId = idCounter.getAndIncrement();
                int   roll  = random.nextInt(10);
                Order order;

                if (roll < 8) { // 80% BUY/SELL
                    Order.Side side = (roll < 4) ? Order.Side.BUY : Order.Side.SELL;
                    double     price = 100.0 + (random.nextDouble() * 4);
                    int        qty   = 1 + random.nextInt(100);
                    order = new Order(seqId, side, price, qty, -1);
                } else { // 20% CANCEL
                    int cancelTarget = Math.max(1, seqId - random.nextInt(50));
                    order = new Order(seqId, Order.Side.CANCEL, 0, 0, cancelTarget);
                }

                // Simulate network latency (remove for stress testing)
                Thread.sleep(random.nextInt(100));

                out.writeObject(order);
                out.flush();
                System.out.printf("[%s] Sent: %s%n", nodeName, order);
            }

            System.out.printf("[%s] Done sending. Closing connection.%n", nodeName);
            // try-with-resources closes socket — server sees EOF, ClientHandler exits
        }
    }
}