Simple Client/Server in Java

Client.java

import java.io.*;
import java.net.*;
import java.util.Scanner;

public class Client {

    public static void main(String[] args) throws UnknownHostException, IOException, ClassNotFoundException  {
        Scanner scan = new Scanner(System.in);
    
    
        Socket socket = new Socket("localhost", 2000);
    
        BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        PrintWriter writer = new PrintWriter(socket.getOutputStream());
        System.out.println("Send information to the server:");
        String response = scan.nextLine();

        writer.write(response);
        writer.println();
        writer.flush(); 

        System.out.println("Sent to server: " + response);
        String s1 = reader.readLine();
        System.out.println("Received from server: " + s1);


        writer.close();
        reader.close();
        scan.close();
        socket.close();
        }
}

Server.java

// package walkthrough;
import java.io.*;
import java.net.*;



public class Server {

    public static void main(String[] args) throws UnknownHostException, IOException, ClassNotFoundException  {
        ServerSocket serverSocket = new ServerSocket(2000);
        System.out.println("Connecting...");
        Socket socket = serverSocket.accept();
        System.out.println("Client connected");

        BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        PrintWriter writer = new PrintWriter(socket.getOutputStream()); 

        String message = reader.readLine();
        System.out.println("Received from client: " + message);

        message = message.toUpperCase();
        String response = message;


        writer.write(response);
        writer.println();
        writer.flush(); 
        System.out.println("Sent to client: " + response);

        writer.close();
        reader.close();
        serverSocket.close();
    
    }
}