Update from task 43d59903-2f84-4a85-a7f2-b01b4c082ed0

.gitignore

@@ -0,0 +1,7 @@
+```
+# Compiled Java classes
+*.class
+
+# Build directory
+bin/
+```

src/TCP/TCPClientGUI.java

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+package TCP;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.*;
+import java.io.*;
+import java.net.*;
+
+public class TCPClientGUI extends JFrame {
+    private JTextField hostField;
+    private JSpinner portSpinner;
+    private JTextArea messageArea;
+    private JTextField inputField;
+    private JButton connectButton;
+    private JButton sendButton;
+    private Socket socket;
+    private PrintWriter out;
+    private BufferedReader in;
+    private boolean connected = false;
+
+    public TCPClientGUI() {
+        super("TCP Client GUI");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(600, 500);
+        setLocationRelativeTo(null);
+
+        // Create components
+        JPanel topPanel = new JPanel(new GridBagLayout());
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(5, 5, 5, 5);
+        gbc.anchor = GridBagConstraints.WEST;
+
+        topPanel.add(new JLabel("Host:"), gbc);
+        gbc.gridx = 1;
+        gbc.weightx = 1.0;
+        gbc.fill = GridBagConstraints.HORIZONTAL;
+        hostField = new JTextField("localhost", 15);
+        topPanel.add(hostField, gbc);
+
+        gbc.gridx = 2;
+        gbc.weightx = 0;
+        gbc.fill = GridBagConstraints.NONE;
+        topPanel.add(new JLabel("Port:"), gbc);
+        gbc.gridx = 3;
+        portSpinner = new JSpinner(new SpinnerNumberModel(5000, 1, 65535, 1));
+        topPanel.add(portSpinner, gbc);
+
+        gbc.gridx = 4;
+        connectButton = new JButton("Connect");
+        connectButton.addActionListener(e -> toggleConnection());
+        topPanel.add(connectButton, gbc);
+
+        // Message display area
+        messageArea = new JTextArea();
+        messageArea.setEditable(false);
+        messageArea.setFont(new Font("Monospaced", Font.PLAIN, 12));
+        JScrollPane scrollPane = new JScrollPane(messageArea);
+        scrollPane.setPreferredSize(new Dimension(0, 300));
+
+        // Input panel
+        JPanel inputPanel = new JPanel(new BorderLayout());
+        inputField = new JTextField();
+        inputField.setEnabled(false);
+        inputField.addActionListener(e -> sendMessage());
+        sendButton = new JButton("Send");
+        sendButton.setEnabled(false);
+        sendButton.addActionListener(e -> sendMessage());
+
+        inputPanel.add(inputField, BorderLayout.CENTER);
+        inputPanel.add(sendButton, BorderLayout.EAST);
+
+        // Layout
+        setLayout(new BorderLayout());
+        add(topPanel, BorderLayout.NORTH);
+        add(scrollPane, BorderLayout.CENTER);
+        add(inputPanel, BorderLayout.SOUTH);
+
+        setVisible(true);
+    }
+
+    private void toggleConnection() {
+        if (!connected) {
+            connect();
+        } else {
+            disconnect();
+        }
+    }
+
+    private void connect() {
+        String host = hostField.getText().trim();
+        int port = (Integer) portSpinner.getValue();
+
+        try {
+            socket = new Socket(host, port);
+            out = new PrintWriter(socket.getOutputStream(), true);
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+
+            connected = true;
+            connectButton.setText("Disconnect");
+            inputField.setEnabled(true);
+            sendButton.setEnabled(true);
+            hostField.setEnabled(false);
+            portSpinner.setEnabled(false);
+            messageArea.append("Connected to server at " + host + ":" + port + "\n");
+
+            // Start reader thread
+            new Thread(this::readFromServer).start();
+
+        } catch (IOException e) {
+            JOptionPane.showMessageDialog(this, "Failed to connect: " + e.getMessage(),
+                    "Connection Error", JOptionPane.ERROR_MESSAGE);
+            disconnect();
+        }
+    }
+
+    private void disconnect() {
+        connected = false;
+        connectButton.setText("Connect");
+        inputField.setEnabled(false);
+        sendButton.setEnabled(false);
+        hostField.setEnabled(true);
+        portSpinner.setEnabled(true);
+        messageArea.append("Disconnected from server\n");
+
+        try {
+            if (socket != null && !socket.isClosed()) {
+                socket.close();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private void readFromServer() {
+        String line;
+        try {
+            while (connected && (line = in.readLine()) != null) {
+                String finalLine = line;
+                SwingUtilities.invokeLater(() -> messageArea.append("Server: " + finalLine + "\n"));
+            }
+        } catch (IOException e) {
+            if (connected) {
+                SwingUtilities.invokeLater(() -> {
+                    messageArea.append("Connection lost: " + e.getMessage() + "\n");
+                    disconnect();
+                });
+            }
+        }
+    }
+
+    private void sendMessage() {
+        String message = inputField.getText().trim();
+        if (!message.isEmpty() && connected) {
+            out.println(message);
+            messageArea.append("You: " + message + "\n");
+            inputField.setText("");
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(TCPClientGUI::new);
+    }
+}

src/TCP/TCPServerGUI.java

@@ -0,0 +1,133 @@
+package TCP;
+
+import javax.swing.*;
+import java.awt.*;
+import java.io.*;
+import java.net.*;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class TCPServerGUI extends JFrame {
+    private JSpinner portSpinner;
+    private JButton startButton;
+    private JTextArea logArea;
+    private ServerSocket serverSocket;
+    private AtomicBoolean running = new AtomicBoolean(false);
+
+    public TCPServerGUI() {
+        super("TCP Server GUI");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(600, 500);
+        setLocationRelativeTo(null);
+
+        // Top panel with port and start button
+        JPanel topPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
+        topPanel.add(new JLabel("Port:"));
+        portSpinner = new JSpinner(new SpinnerNumberModel(5000, 1, 65535, 1));
+        topPanel.add(portSpinner);
+        startButton = new JButton("Start Server");
+        startButton.addActionListener(e -> toggleServer());
+        topPanel.add(startButton);
+
+        // Log area
+        logArea = new JTextArea();
+        logArea.setEditable(false);
+        logArea.setFont(new Font("Monospaced", Font.PLAIN, 12));
+        JScrollPane scrollPane = new JScrollPane(logArea);
+
+        // Layout
+        setLayout(new BorderLayout());
+        add(topPanel, BorderLayout.NORTH);
+        add(scrollPane, BorderLayout.CENTER);
+
+        setVisible(true);
+    }
+
+    private void toggleServer() {
+        if (!running.get()) {
+            startServer();
+        } else {
+            stopServer();
+        }
+    }
+
+    private void startServer() {
+        int port = (Integer) portSpinner.getValue();
+        try {
+            serverSocket = new ServerSocket(port);
+            running.set(true);
+            startButton.setText("Stop Server");
+            portSpinner.setEnabled(false);
+            logArea.append("TCP Server started on port " + port + "\n");
+
+            // Accept clients in a separate thread
+            new Thread(this::acceptClients).start();
+
+        } catch (IOException e) {
+            JOptionPane.showMessageDialog(this, "Failed to start server: " + e.getMessage(),
+                    "Server Error", JOptionPane.ERROR_MESSAGE);
+            stopServer();
+        }
+    }
+
+    private void acceptClients() {
+        while (running.get()) {
+            try {
+                Socket clientSocket = serverSocket.accept();
+                logArea.append("Client connected: " + clientSocket.getInetAddress() + "\n");
+
+                // Handle each client in a separate thread
+                new Thread(() -> handleClient(clientSocket)).start();
+
+            } catch (IOException e) {
+                if (running.get()) {
+                    logArea.append("Error accepting client: " + e.getMessage() + "\n");
+                }
+            }
+        }
+    }
+
+    private void handleClient(Socket clientSocket) {
+        try (BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+             PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true)) {
+
+            String message;
+            while ((message = in.readLine()) != null) {
+                String finalMessage = message;
+                SwingUtilities.invokeLater(() -> 
+                    logArea.append("Received from " + clientSocket.getInetAddress() + ": " + finalMessage + "\n"));
+
+                String response = "Echo: " + message;
+                out.println(response);
+            }
+
+        } catch (IOException e) {
+            SwingUtilities.invokeLater(() -> 
+                logArea.append("Client disconnected: " + clientSocket.getInetAddress() + "\n"));
+        } finally {
+            try {
+                clientSocket.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private void stopServer() {
+        running.set(false);
+        startButton.setText("Start Server");
+        portSpinner.setEnabled(true);
+        logArea.append("TCP Server stopped\n");
+
+        try {
+            if (serverSocket != null && !serverSocket.isClosed()) {
+                serverSocket.close();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(TCPServerGUI::new);
+    }
+}