Initial chat room

src/main/java/org/example/ClientApp.java

@@ -0,0 +1,111 @@
+package org.example;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+
+public class ClientApp extends JFrame {
+    private static final String SERVER_IP = "localhost";
+    private static final int SERVER_PORT = 1234;
+
+    private JTextArea chatArea;
+    private JTextField messageField;
+    private JButton sendButton;
+
+    private Socket socket;
+    private BufferedReader in;
+    private PrintWriter out;
+
+    public ClientApp() {
+        setTitle("Chat Client");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(400, 300);
+        setLayout(new BorderLayout());
+
+        chatArea = new JTextArea();
+        chatArea.setEditable(false);
+        add(new JScrollPane(chatArea), BorderLayout.CENTER);
+
+        JPanel bottomPanel = new JPanel();
+        bottomPanel.setLayout(new BorderLayout());
+
+        messageField = new JTextField();
+        bottomPanel.add(messageField, BorderLayout.CENTER);
+
+        sendButton = new JButton("Send");
+        sendButton.addActionListener(new ActionListener() {
+            @Override
+            public void actionPerformed(ActionEvent e) {
+                sendMessage();
+            }
+        });
+        bottomPanel.add(sendButton, BorderLayout.EAST);
+
+        add(bottomPanel, BorderLayout.SOUTH);
+
+        setVisible(true);
+
+        connectToServer();
+        startListening();
+    }
+
+    private void connectToServer() {
+        try {
+            socket = new Socket(SERVER_IP, SERVER_PORT);
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            out = new PrintWriter(socket.getOutputStream(), true);
+            chatArea.append("Connected to server\n");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private void startListening() {
+        Thread thread = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    String serverMessage;
+                    while ((serverMessage = in.readLine()) != null) {
+                        chatArea.append("Server: " + serverMessage + "\n");
+                    }
+                } catch (IOException e) {
+                    e.printStackTrace();
+                } finally {
+                    try {
+                        in.close();
+                        out.close();
+                        socket.close();
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        });
+        thread.start();
+    }
+
+    private void sendMessage() {
+        String message = messageField.getText().trim();
+        if (!message.isEmpty()) {
+            out.println(message);
+            messageField.setText("");
+            chatArea.append("You: " + message + "\n");
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(new Runnable() {
+            @Override
+            public void run() {
+                new ClientApp();
+            }
+        });
+    }
+}

src/main/java/org/example/Main.java

@@ -1,19 +0,0 @@
-package org.example;
-
-// Press Shift twice to open the Search Everywhere dialog and type `show whitespaces`,
-// then press Enter. You can now see whitespace characters in your code.
-public class Main {
-    public static void main(String[] args) {
-        // Press Alt+Enter with your caret at the highlighted text to see how
-        // IntelliJ IDEA suggests fixing it.
-        System.out.println("Hello and welcome!");
-
-        // Press Shift+F10 or click the green arrow button in the gutter to run the code.
-        for (int i = 1; i <= 5; i++) {
-
-            // Press Shift+F9 to start debugging your code. We have set one breakpoint
-            // for you, but you can always add more by pressing Ctrl+F8.
-            System.out.println("i = " + i);
-        }
-    }
-}

src/main/java/org/example/ServerApp.java

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+package org.example;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ServerApp {
+    private static final int PORT = 1234;
+    private List<ClientHandler> clients;
+
+    public ServerApp() {
+        clients = new ArrayList<>();
+    }
+
+    public void start() {
+        try {
+            ServerSocket serverSocket = new ServerSocket(PORT);
+            System.out.println("Server started on port " + PORT);
+
+            while (true) {
+                Socket clientSocket = serverSocket.accept();
+                System.out.println("New client connected: " + clientSocket);
+
+                ClientHandler clientHandler = new ClientHandler(clientSocket);
+                clients.add(clientHandler);
+                clientHandler.start();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private void broadcastMessage(String message, ClientHandler sender) {
+        for (ClientHandler client : clients) {
+            if (client != sender) {
+                client.sendMessage(message);
+            }
+        }
+    }
+
+    private void removeClient(ClientHandler client) {
+        clients.remove(client);
+    }
+
+    private class ClientHandler extends Thread {
+        private Socket clientSocket;
+        private BufferedReader in;
+        private PrintWriter out;
+
+        public ClientHandler(Socket socket) {
+            this.clientSocket = socket;
+        }
+
+        @Override
+        public void run() {
+            try {
+                in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+                out = new PrintWriter(clientSocket.getOutputStream(), true);
+
+                String clientMessage;
+                while ((clientMessage = in.readLine()) != null) {
+                    broadcastMessage(clientMessage, this);
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
+            } finally {
+                try {
+                    in.close();
+                    out.close();
+                    clientSocket.close();
+                    removeClient(this);
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        public void sendMessage(String message) {
+            out.println(message);
+        }
+    }
+
+    public static void main(String[] args) {
+        ServerApp server = new ServerApp();
+        server.start();
+    }
+}