Server.java

import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(5000); // port
        System.out.println("Server is running...");

        Socket socket = serverSocket.accept(); // waits for client
        System.out.println("Client connected!");

        DataInputStream in = new DataInputStream(socket.getInputStream());
        DataOutputStream out = new DataOutputStream(socket.getOutputStream());

        String message = in.readUTF();
        System.out.println("Client says: " + message);

        out.writeUTF("Hello from Server!");

        socket.close();
        serverSocket.close();
    }
}