Я создаю простое приложение Knock Knock (программирование сокетов), в котором есть сервер localhost и клиент.

Server: Knock Knock
Client: Who's there?
Server: Turnip.
Client: Turnip Who?
Server: Turnip the heat.

Так вот как должна идти программа. но дело в том, что мой графический интерфейс не показывает никаких сообщений. на моей области текста. Вот мои коды.

Сервер:

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

public class KnockKnockServer {
    public static void main(String[] args) throws IOException {

        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(4444);
        } catch (IOException e) {
            System.err.println("Could not listen on port: 4444.");
            System.exit(1);
        }

        Socket clientSocket = null;
        try {
            clientSocket = serverSocket.accept();
        } catch (IOException e) {
            System.err.println("Accept failed.");
            System.exit(1);
        }

        PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(
                new InputStreamReader(
                clientSocket.getInputStream()));
        String inputLine, outputLine;
        KnockKnockProtocol kkp = new KnockKnockProtocol();

        outputLine = kkp.processInput(null);
        out.println(outputLine);

        while ((inputLine = in.readLine()) != null) {
             outputLine = kkp.processInput(inputLine);
             out.println(outputLine);
             if (outputLine.equals("Bye."))
                break;
        }
        out.close();
        in.close();
        clientSocket.close();
        serverSocket.close();
    }
}

Протокол KnockKnockProtocol

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

public class KnockKnockProtocol {
    private static final int WAITING = 0;
    private static final int SENTKNOCKKNOCK = 1;
    private static final int SENTCLUE = 2;
    private static final int ANOTHER = 3;

    private static final int NUMJOKES = 5;

    private int state = WAITING;
    private int currentJoke = 0;

    private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who", "Who" };
    private String[] answers = { "Turnip the heat, it's cold in here!",
                                 "I didn't know you could yodel!",
                                 "Bless you!",
                                 "Is there an owl in here?",
                                 "Is there an echo in here?" };

    public String processInput(String theInput) {
        String theOutput = null;

        if (state == WAITING) {
            theOutput = "Knock! Knock!";
            state = SENTKNOCKKNOCK;
        } else if (state == SENTKNOCKKNOCK) {
            if (theInput.equalsIgnoreCase("Who's there?")) {
                theOutput = clues[currentJoke];
                state = SENTCLUE;
            } else {
                theOutput = "You're supposed to say \"Who's there?\"! " +
                "Try again. Knock! Knock!";
            }
        } else if (state == SENTCLUE) {
            if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) {
                theOutput = answers[currentJoke] + " Want another? (y/n)";
                state = ANOTHER;
            } else {
                theOutput = "You're supposed to say \"" + 
                clues[currentJoke] + 
                " who?\"" + 
                "! Try again. Knock! Knock!";
                state = SENTKNOCKKNOCK;
            }
        } else if (state == ANOTHER) {
            if (theInput.equalsIgnoreCase("y")) {
                theOutput = "Knock! Knock!";
                if (currentJoke == (NUMJOKES - 1))
                    currentJoke = 0;
                else
                    currentJoke++;
                state = SENTKNOCKKNOCK;
            } else {
                theOutput = "Bye.";
                state = WAITING;
            }
        }
        return theOutput;
    }
}

Клиент.

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


public class KnockKnockClient {

    public String fromServer;
    public String fromUser;

    public void Client() throws IOException {

        Socket kkSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;


        try {
            kkSocket = new Socket("127.0.0.1", 4444);
            out = new PrintWriter(kkSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: 127.0.0.1");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: 127.0.0.1");
            System.exit(1);
        }

        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));

        while ((fromServer = in.readLine()) != null) {
            System.out.println("Server: " + fromServer);

            if (fromServer.equals("Bye."))
                break;

            fromUser = stdIn.readLine();
        if (fromUser != null) {
                System.out.println("Client: " + fromUser);
                out.println(fromUser);
        }
        }

        out.close();
        in.close();
        stdIn.close();
        kkSocket.close();
    }


}

И пользовательский интерфейс

 import java.awt.event.ActionListener;



    public class KnockKnockWindow extends JFrame {

        JTextArea clientTextArea;
        JTextArea serverTextArea;
        JButton submitButton;


        public KnockKnockWindow() {

            super("Chat Window");
            setVisible(true);
            setDefaultCloseOperation(EXIT_ON_CLOSE);
            setLocationRelativeTo(null);
            setSize(420,228);

            getContentPane().setLayout(null);

            clientTextArea = new JTextArea();
            clientTextArea.setBounds(10, 118, 278, 51);
            getContentPane().add(clientTextArea);


            serverTextArea = new JTextArea();
            serverTextArea.setBounds(10, 11, 278, 96);
            getContentPane().add(serverTextArea);

            submitButton = new JButton("Submit");
            submitButton.setBounds(298, 118, 89, 51);
            getContentPane().add(submitButton);
        }


        public void setServerText(String fromServer){
            serverTextArea.setText(fromServer);
        }

        public void setClientText(String fromClient){
            clientTextArea.setText(fromClient);
        }

        public String returnClientText(){
            return clientTextArea.getText();
        }

        public void addSubmitListener(ActionListener sub){
            submitButton.addActionListener(sub);
        }

    }   



The Controller


import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class KnockKnockController {

    private KnockKnockClient client;
    private KnockKnockWindow window;

    public KnockKnockController(KnockKnockClient client, KnockKnockWindow window){
        this.client = client;
        this.window = window;

        window.addSubmitListener(new SubmitListener());
        window.setServerText(client.fromServer);
    }

    public class SubmitListener implements ActionListener{

        public void actionPerformed(ActionEvent arg0) {
            client.fromUser = window.returnClientText();
        }
    }
}

И главное приложение

import javax.swing.JFrame;

public class KnockTest extends JFrame{

    public static void main (String[] args){
        KnockKnockClient kkcl = new KnockKnockClient();
        KnockKnockWindow kkw = new KnockKnockWindow();
        KnockKnockController kkc = new KnockKnockController(kkcl,kkw);
    }
}

Сначала мы запустим сервер, затем основной.

Но почему я не получаю никаких сообщений от сервера? когда я нажимаю начать. В текстовой области Сервера должно быть написано KnockKnock. но кажется, что это не показывает, любая идея? извините за длинный пост кода, но я не знаю, чтобы сократить их здесь. так как я знаю, что большинство из них важны