Want client to communicate with server

Question

I am making a client/server application with the client being an applet and the server a program. The program is for a fictional chinese restaurant where the user selected a dish (using four radio buttons) and depending on the radio button selected, four ingrediants show as check boxes(their value also changes depending on the radio button selected).
I want the client to inform the server which radio button and check boxes have been selected so that the server can return the different ingrediants and their values in addition to working out the total price for the ingrediants selected. The problem is, I am unsure as to how to achieve this. Here is my code, I know it has problems, but i think it is generally OK:
client code:
import java.io.*;
import java.net.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class AppletClientClass extends Applet implements
ActionListener {
     radPanel = new Panel();
     chePanel = new Panel();
     radio = new CheckboxGroup();
     radioOne = new Checkbox("Set Dinner A", false, radio);
     radPanel.add(radioOne);
     radioOne.addItemListener(this);
     radioTwo = new Checkbox("Set Dinner B", false, radio);
     radPanel.add(radioTwo);
     radioTwo.addItemListener(this);
     radioThree = new Checkbox("Set Dinner C", false, radio);
     radPanel.add(radioThree);
     radioThree.addItemListener(this);
     radioFour = new Checkbox("Set Dinner D", false, radio);
     radPanel.add(radioFour);
     radioFour.addItemListener(this);
     checkOne = new Checkbox(" ");
     chePanel.add(checkOne);
     checkOne.addItemListener(this);
     checkTwo = new Checkbox("ingre. 2");
     chePanel.add(checkTwo);
     checkTwo.addItemListener(this);
     checkThree = new Checkbox("ingre. 2");
     chePanel.add(checkThree);
     checkThree.addItemListener(this);
     checkFour = new Checkbox("ingre. 2");
     chePanel.add(checkFour);
     checkFour.addItemListener(this);
     checkFive = new Checkbox("ingre. 2");
     chePanel.add(checkFive);
     checkFive.addItemListener(this);
     txtField = new TextField (40);
     add(txtField);
     add(radPanel);
     add(chePanel);
     public void actionPerformed (ActionEvent ev) {
     try
Socket cts = new
Socket(getCodeBase().getHost(), 6000);
     DataInputStream isfs = new
DataInputStream(cts.getInputStream());
     DataOutputStream osts = new
DataOutputStream(cts.getOutputStream());
          osts.writeDouble(Double.parseDouble(unknown));//want this line to tell the server which buttons have been selected
     osts.flush();
     double input = isfs.readDouble(sum);
          txtField.setText("�" + String.valueOf(sum));
} catch (IOException ex) {
               System.out.println(ex);
Server code:
import java.io.*;
import java.net.*;
import java.awt.*;
public class AppletServerClass {
     public static void main(String[] args) {
          try
               ServerSocket ss = new ServerSocket(6000);
               Socket ctc = ss.accept(); // ctc = connect to client
               DataInputStream isfc = new DataInputStream(ctc.getInputStream()); // isfc = input stream from client
               DataOutputStream ostc = new DataOutputStream(ctc.getOutputStream()); // output stream to client
               double input = isfc.readDouble();
          double sum = 0;
          double ingre1 = 0;
          double ingre2 = 0;
          double ingre3 = 0;
          double ingre4 = 0;
          double ingre5 = 0;
          double totalIngre1 = 0;
          double totalIngre2 = 0;
          double totalIngre3 = 0;
          double totalIngre4 = 0;
          double totalIngre5 = 0;
          if(radioOne.getState() == true) // prices and ingredients if radio button one is selected
               ingre1 = 3.5;
               ingre2 = 6;
               ingre3 = 9;
               ingre4 = 12;
               ingre5 = 7;
               checkOne.setLabel("CurrySauce");
               checkTwo.setLabel("Egg Fried Rice");
               checkThree.setLabel("Chicken Chow Mein");
               checkFour.setLabel("Prawn Crackers");
               checkFive.setLabel("Meatballs");
          if (radioTwo.getState() == true) // prices and ingredients if radio button two is selected
               ingre1 = 5;
               ingre2 = 4;
               ingre3 = 7;
               ingre4 = 8;
               ingre5 = 2;
               checkOne.setLabel("Chips");
               checkTwo.setLabel("Egg Fried Rice");
               checkThree.setLabel("Chicken Chop Suey");
               checkFour.setLabel("Fried Duck");
               checkFive.setLabel("Omelette");
          if (radioThree.getState() == true)// prices and ingredients if radio button three is selected
               ingre1 = 4;
               ingre2 = 5;
               ingre3 = 8;
               ingre4 = 9;
               ingre5 = 8;
               checkOne.setLabel("Chicken");
               checkTwo.setLabel("Curry");
               checkThree.setLabel("Cod");
               checkFour.setLabel("Noodles");
               checkFive.setLabel("Meatballs");
          if (radioFour.getState() == true)// prices and ingredients if radio button four is selected
               ingre1 = 4;
               ingre2 = 3;
               ingre3 = 6;
               ingre4 = 2;
               ingre5 = 4;
               checkOne.setLabel("Roast Duck");
               checkTwo.setLabel("Noodles");
               checkThree.setLabel("Fried Squid");
               checkFour.setLabel("Soup");
               checkFive.setLabel("Fish");
          if (checkOne.getState() == true)
               totalIngre1 = ingre1;
          if (checkTwo.getState() == true)
               totalIngre2 = ingre2;
          if (checkThree.getState() == true)
               totalIngre3 = ingre3;
          if (checkFour.getState() == true)
               totalIngre4 = ingre4;
          if (checkFive.getState() == true)
               totalIngre5 = ingre5;
               sum = totalIngre1 + totalIngre2 + totalIngre3 + totalIngre4 + totalIngre5;
               ostc.writeDouble(sum);
               ostc.flush();
               System.out.println("The total price for this meal is " + sum);
          } catch (IOException e) {
               System.out.println(e);

Answer 1

I've not looked over your code extrememly closely, but it looks like you might be mixing client and server responsibilities. In your client you need to have all the code that deals with the UI. There shouldn't be any mention of labels or check boxes in the server code. You might want the flow to be:
Client:
Presents a series of radio buttons for meal possibilities
Queries the server for a list of ingredients for a selected meal
Displays a meal-sensitive list of ingredients
Submits the order to the server
Server
Accepts a request for a meal ingredient list
Responds with the ingredient list
Accepts an order
responds with a total
Then you need to work out how the client sends the meal possibility to the server, your current scheme of a double works, but it's easier (IMO) to use a String as a generic parameter type to move things back and forth with - that way you are always dealing with Strings. And you need to work out how the server sends an ingredient list to the client - you could use a delimited String and tokenize it. And then you need to work out how the client submits a finished order to the server, maybe a String that says "ORDER_COMPLETE" or something, with a delimited list of ingredients and the meal key.
I hope that made sense, and good luck
Lee