How can I write my code in a way that the client can send another data to the server? (POS TCP server is in Java, client is NodeJS)

Question

I am having trouble analyzing my code. I am creating a POS application with TCP implementation. This POS does not have a database and only reads from a text file. The Server is written in java and the Client is in NodeJS. I want to be able to send another data (find a Product ID) to the server from the client side, but right now I can't figure out how to do that. Please help.

What can I do specifically with the "client.write("findProduct,351082\n")" in the index.js (Client) file?

The problem: After running both the server and client applications, I type Option "2" then type, "findProduct,351082\n" for the client side. And I get a response from the server that the Product has been found with the product ID given above. However, what I'm trying to achieve is that I want to be able to send another data to the server from the client side to find another Product. So, what efficient way can I write my code to do this?

Here is the App.java (Server)

public static void main(String[] args) {
    System.out.println(new App().getGreeting());

    Socket socket = null;
    InputStreamReader inputStreamReader = null;
    OutputStreamWriter outputStreamWriter = null;
    BufferedReader bufferedReader = null;
    BufferedWriter bufferedWriter = null;
    ServerSocket serverSocket = null;
    File selectedFile = new File("src/main/java/pos_server/products.txt");

    try {
        serverSocket = new ServerSocket(3005);
    } catch (IOException e1) {
        e1.printStackTrace();
    }

    while (true) {
        try {
            socket = serverSocket.accept();

            inputStreamReader = new InputStreamReader(socket.getInputStream());
            outputStreamWriter = new OutputStreamWriter(socket.getOutputStream());
            bufferedReader = new BufferedReader(inputStreamReader);
            bufferedWriter = new BufferedWriter(outputStreamWriter);

            while (true) {
                // Reads the message from client
                String msgFromClient = bufferedReader.readLine();

                System.out.println("Client: " + msgFromClient);

                String[] separatedInput = msgFromClient.split(",", 2);

                // Add to Cart
                // Input expected is "findProduct,[productID]"
                if (separatedInput[0].equals("findProduct")) {
                    try(Scanner scanner = new Scanner(selectedFile)) {
                        scanner.useDelimiter(";");
                        Boolean productFound = false;
                        while(scanner.hasNext()) {
                            String scannedText = scanner.next();
                            String[] s = scannedText.split(",");
                            Integer scannedID = Integer.parseInt(s[0]);

                            if(Objects.equals(Integer.parseInt(separatedInput[1]), scannedID)){
                                bufferedWriter.write("Product:" + scannedText);
                                bufferedWriter.newLine();
                                System.out.println("Product found!");
                                productFound = true;
                                break;
                            }  
                            scanner.nextLine();
                        }
                        if (!productFound) {
                            bufferedWriter.write("Product not found.");
                            bufferedWriter.newLine();
                        }
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }

                // Saving Transaction
                // if (separatedInput[0].equals("saveTransaction")) {
                //     // store the transaction somewhere
                // }

                // Sends message to client
                bufferedWriter.flush();

                if (msgFromClient.equalsIgnoreCase("BYE")) {
                    break;
                }
            }
            socket.close();
            inputStreamReader.close();
            outputStreamWriter.close();
            bufferedReader.close();
            bufferedWriter.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Here is the index.js(Client)

const net = require("net")
const prompt = require("prompt-sync")()
const readlineSync = require("readline-sync");
const colors = require("colors");
var HOST = "127.0.0.1";
var PORT = 3005;

var client = null;

// For Opening/Starting connection
function OpenConnection(){
if(client){
    console.log("--Connection is already open--".red);
    setTimeout(function(){
        menu();
    }, 0);
    return;
}

client = new net.Socket();
client.on("error", function (err) {
    client.destroy();
    client = null;
    console.log("ERROR: Connection could not be started. Msg: %s".red, err.message);
    setTimeout(function(){
        menu();
    }, 0);
});

client.on("data", function (data){
    console.log("Received: %s".cyan, data);
    setTimeout(function(){
        menu();
    }, 0);
});

client.connect(PORT, HOST, function () {
    console.log("Connection opened successfully!".green);
    setTimeout(function(){
        menu();
    }, 0);
});
}

 // Sending Data 
function SendData(data){
if (!client){
    console.log("--Connection is neither open nor closed--".red);
    setTimeout(function(){
        menu();
    }, 0);
    return;
}
client.write("findProduct,351082\n")
}

 // Closing Connections
function CloseConnection(){
if(!client){
    console.log("--Connection is not open or have already been closed--".red);
    setTimeout(function(){
        menu();
    }, 0);
    return;
}
client.destroy();
client = null;
console.log("Connection closed successfully!".yellow);
}

// Menu Option
function menu(){
var lineRead = readlineSync.question("\n\nEnter option (1: Start Connection, 2: Send Data, 3: Close Connection):");

switch(lineRead){
case "1": 
    OpenConnection();
    break;
case "2":
    var data = readlineSync.question("Enter Product ID:");
    SendData(data);
    break;
case "3":
    CloseConnection();
    return;
    break;
default:
    setTimeout(function(){
        menu();
    }, 0);
    break;
    }
    }

setTimeout(function(){
  menu();
 }, 0);

Here is the products.txt file

571904,Wine - Chablis J Moreau Et Fils,1130.85;
369107,Relish,945.61;
485124,Coffee - Egg Nog Capuccino,1312.76;
398370,Grenadine,1648.24;
879376,Island Oasis - Pina Colada,1646.43;
535722,Salmon - Sockeye Raw,837.7;
539361,Mix - Cappucino Cocktail,1761.9;
744220,Cheese - Parmesan Grated,2388.78;
985526,Beer - Blue Light,2388.74;
351082,Cocktail Napkin Blue,185.74;