implement socket-programming chat server and client core logic

.idea/.name

@@ -0,0 +1 @@
+chatClient.java

.idea/misc.xml

@@ -8,7 +8,7 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="25" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21_PREVIEW" project-jdk-name="21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

pom.xml

@@ -9,8 +9,8 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <maven.compiler.source>25</maven.compiler.source>
+        <maven.compiler.source>21</maven.compiler.source>
-        <maven.compiler.target>25</maven.compiler.target>
+        <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 

src/main/java/com/university/chat/Client/ServerListener.java

@@ -1,20 +1,37 @@
 package com.university.chat.Client;
 
-public class ServerListener implements Runnable{
+import com.university.chat.Common.ChatMessage;
-    // TODO: store the ObjectInputStream from the user socket
+import com.university.chat.Common.FileMessage;
-    //          (this should be the same input stream the
+
-    //           chatClient created when connecting)
+import java.io.ObjectInputStream;
+
+public class ServerListener implements Runnable {
+
+    // ذخیره ObjectInputStream دریافتی از چت‌کلاینت اصلی
+    private final ObjectInputStream in;
+
+    public ServerListener(ObjectInputStream in) {
+        this.in = in;
+    }
 
     @Override
     public void run() {
         try {
-            // TODO: In an infinite loop read objects from the server
+            // حلقه بی‌انتها برای خواندن مداوم آبجکت‌ها از سرور
-            //   - if it's a ChatMessage  -> print "<sender>: <content>"
+            while (true) {
-            //   - if it's a FileMessage  -> print that a file was received
+                Object serverData = in.readObject();
-            //                               (filename + sender), it's already
+
-            //                               saved to disk by the server.
+                if (serverData instanceof ChatMessage msg) {
-        } catch (Exception e){
+                    // چاپ پیام‌های متنی دریافتی (سیستمی، عمومی یا خصوصی)
+                    System.out.println(msg.getSender() + ": " + msg.getContent());
+                } else if (serverData instanceof FileMessage fileMsg) {
+                    // اعلام دریافت موفقیت‌آمیز فایل که سرور از قبل ذخیره‌اش کرده
+                    System.out.println("[Notification] File received: '" + fileMsg.getFilename() +
+                            "' from user '" + fileMsg.getSender() + "'. Saved on disk.");
+                }
+            }
+        } catch (Exception e) {
             System.out.println("Disconnected from server");
         }
     }
-}
+}

src/main/java/com/university/chat/Client/chatClient.java

@@ -1,29 +1,128 @@
 package com.university.chat.Client;
 
-public class chatClient {
+import com.university.chat.Common.ChatMessage;
-    public static void main() {
+import com.university.chat.Common.FileMessage;
-        // TODO: Connecting to the server
+import com.university.chat.Common.MessageType;
-        //  1. Create a socket and connect to the server
-        //  2. Create an ObjectOutputStream (out) and ObjectInputStream (in)
-        //      from the socket's streams — output FIRST, then input.
-        //  2. Get the username, and send a LOGIN ChatMessage with that username
-        //  3. Start a new Thread running a ServerListener(in) so incoming
-        //      messages are handled concurrently.
 
-        while (true){
+import java.io.BufferedReader;
-            try {
+import java.io.File;
-                // TODO: Program loop — read a line from the console and act on it:
+import java.io.InputStreamReader;
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+import java.io.ObjectInputStream;
-                //   - "/users"                    -> build & send a USER_LIST request
+import java.io.ObjectOutputStream;
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+import java.net.Socket;
-                //                                     (you can use TransferProgress
+import java.nio.file.Files;
-                //                                     to show progress)
+
-                //                                     and send it as a FileMessage
+public class chatClient {
-                //   - anything else               -> send a PUBLIC_MESSAGE
+    private static Socket socket;
-                //   Remember to flush() the output stream after writeObject().
+    private static ObjectOutputStream out;
-            } catch (Exception e){
+    private static ObjectInputStream in;
-                System.out.println("command failed: " + e.getMessage());
+    private static BufferedReader consoleReader;
+
+    public static void main(String[] args) {
+        String host = "127.0.0.1";
+        int port = 12345;
+
+        try {
+            consoleReader = new BufferedReader(new InputStreamReader(System.in));
+
+            // ۱. اتصال سوکت و ایجاد تقدمی استریم‌ها
+            socket = new Socket(host, port);
+            out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            in = new ObjectInputStream(socket.getInputStream());
+
+            System.out.print("Enter your username: ");
+            String username = consoleReader.readLine();
+            if (username == null || username.trim().isEmpty()) {
+                username = "Anonymous";
             }
+
+            // ارسال پکت ورود با فرمت ۴ پارامتری درست
+            ChatMessage loginMsg = new ChatMessage(MessageType.LOGIN, username, "Server", username);
+            out.writeObject(loginMsg);
+            out.flush();
+
+            // شروع کار ترد شنونده بک‌گراند
+            ServerListener serverListener = new ServerListener(in);
+            Thread listenerThread = new Thread(serverListener);
+            listenerThread.setDaemon(true);
+            listenerThread.start();
+
+            System.out.println("Connected to server! Available commands:\n" +
+                    " - /msg <user> <text>\n" +
+                    " - /users\n" +
+                    " - /sendfile <user> <path>\n" +
+                    " - Or just type anything to send a public message.\n");
+
+            // ۲. حلقه برنامه برای دریافت دستورات ترمینال
+            while (true) {
+                String line = consoleReader.readLine();
+                if (line == null) break;
+                if (line.trim().isEmpty()) continue;
+
+                try {
+                    if (line.startsWith("/msg ")) {
+                        String[] parts = line.split(" ", 3);
+                        if (parts.length >= 3) {
+                            String receiver = parts[1];
+                            String text = parts[2];
+                            ChatMessage privateMsg = new ChatMessage(MessageType.PRIVATE_MESSAGE, username, receiver, text);
+                            out.writeObject(privateMsg);
+                        } else {
+                            System.out.println("Usage: /msg <user> <text>");
+                        }
+                    } else if (line.equals("/users")) {
+                        ChatMessage listReq = new ChatMessage(MessageType.USER_LIST, username, "Server", "");
+                        out.writeObject(listReq);
+                    } else if (line.startsWith("/sendfile ")) {
+                        String[] parts = line.split(" ", 3);
+                        if (parts.length >= 3) {
+                            String receiver = parts[1];
+                            String filepath = parts[2];
+                            File file = new File(filepath);
+
+                            if (file.exists() && file.isFile()) {
+                                byte[] fileData = Files.readAllBytes(file.toPath());
+                                FileMessage fileMsg = new FileMessage(username, receiver, file.getName(), fileData);
+                                out.writeObject(fileMsg);
+                                System.out.println("File sent to server for routing...");
+                            } else {
+                                System.out.println("File not found at path: " + filepath);
+                            }
+                        } else {
+                            System.out.println("Usage: /sendfile <user> <path>");
+                        }
+                    } else {
+                        ChatMessage publicMsg = new ChatMessage(MessageType.PUBLIC_MESSAGE, username, "All", line);
+                        out.writeObject(publicMsg);
+                    }
+                    out.flush();
+                } catch (Exception e) {
+                    System.out.println("Command failed: " + e.getMessage());
+                }
+            }
+        } catch (Exception e) {
+            System.out.println("Client error: " + e.getMessage());
+        } finally {
+            cleanup();
         }
     }
-}
+
+    // متد کلین‌آپ مطابق دقیق ساختار عکسی که فرستادی برای آزادسازی پورت‌ها
+    private static void cleanup() {
+        try {
+            if (in != null) in.close();
+        } catch (Exception ignored) {}
+        try {
+            if (out != null) out.close();
+        } catch (Exception ignored) {}
+        try {
+            if (consoleReader != null) consoleReader.close();
+        } catch (Exception ignored) {}
+        try {
+            if (socket != null && !socket.isClosed()) {
+                socket.close();
+            }
+        } catch (Exception ignored) {}
+    }
+}

src/main/java/com/university/chat/Server/ChatServer.java

@@ -1,15 +1,32 @@
 package com.university.chat.Server;
 
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
 public class ChatServer {
-    // TODO: declare a single shared UserManager instance (static final)
+    // تعریف نمونه اشتراکی UserManager به صورت static final برای دسترسی تمام جلسات
-    //         This MUST be shared by all ClientSession threads so that
+    private static final UserManager userManager = new UserManager();
-    //         broadcasting and private messaging work correctly.
+    private static final int PORT = 12345;
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        System.out.println("Advanced Chat Server starting...");
+        // ساخت ServerSocket روی پورت مشخص شده
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
+            System.out.println("Server is running and listening on port " + PORT);
 
-        // TODO: In an infinite loop:
+            // حلقه بی‌انتها برای پذیرش کلاینت‌های جدید
-        //  accept an incoming client connection
+            while (true) {
-        //  make a new thread running ClientSession for each user.
+                Socket clientSocket = serverSocket.accept();
+                System.out.println("New client connected from: " + clientSocket.getRemoteSocketAddress());
+
+                // ساخت یک ClientSession جدید و سپردن آن به یک ترد مجزا
+                ClientSession session = new ClientSession(clientSocket, userManager);
+                Thread sessionThread = new Thread(session);
+                sessionThread.start();
+            }
+        } catch (IOException e) {
+            System.err.println("Server exception: " + e.getMessage());
+        }
     }
-}
+}

src/main/java/com/university/chat/Server/ClientSession.java

@@ -2,70 +2,146 @@ package com.university.chat.Server;
 
 import com.university.chat.Common.ChatMessage;
 import com.university.chat.Common.FileMessage;
+import com.university.chat.Common.MessageType;
 
 import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 import java.net.Socket;
 import java.nio.file.Files;
 
 public class ClientSession implements Runnable {
 
+    private final Socket socket;
+    private final UserManager userManager;
+    private ObjectOutputStream out;
+    private ObjectInputStream in;
     private String username;
 
     public ClientSession(Socket socket, UserManager userManager) {
-        // TODO : Create an ObjectOutputStream from socket.getOutputStream()
+        this.socket = socket;
-        //         and an ObjectInputStream from socket.getInputStream().
+        this.userManager = userManager;
+        try {
+            // ایجاد استریم خروجی قبل از ورودی جهت جلوگیری از Stream Deadlock
+            this.out = new ObjectOutputStream(socket.getOutputStream());
+            this.out.flush();
+            this.in = new ObjectInputStream(socket.getInputStream());
+        } catch (IOException e) {
+            System.err.println("Error initializing streams: " + e.getMessage());
+        }
     }
 
     @Override
     public void run() {
         try {
+            // ۱. فرآیند لاگین کلاینت
+            Object firstObject = in.readObject();
+            if (firstObject instanceof ChatMessage msg && msg.getType() == MessageType.LOGIN) {
+                this.username = msg.getSender();
 
-            // TODO: Welcome the user (login step)
+                // ثبت کاربر در UserManager فعال سرور
-            //  1. Read the first object sent by the client.
+                if (!userManager.addUser(username, this)) {
-            //  2. Check it's a ChatMessage with type LOGIN.
+                    ChatMessage failMsg = new ChatMessage(MessageType.LOGIN_FAILED, "Server", username, "Username already taken.");
-            //  3. Extract the username.
+                    out.writeObject(failMsg);
-            //  4. Try to register the user via userManager.addUser(...).
+                    out.flush();
-            //  5. If the username is taken, send back LOGIN_FAILED and close the socket.
+                    socket.close();
-            //  6. Otherwise, create the user's folders with FileManager.createUserFolders(...)
+                    return;
-            //      and send back LOGIN_SUCCESS.
+                } else {
+                    // ایجاد پوشه‌های کاربر روی دیسک سرور و تایید لاگین
+                    FileManager.createUserFolders(username);
+                    ChatMessage successMsg = new ChatMessage(MessageType.LOGIN_SUCCESS, "Server", username, "Welcome to the chat!");
+                    out.writeObject(successMsg);
+                    out.flush();
+                    System.out.println("User " + username + " successfully logged in.");
 
-            // TODO: Main message loop
+                    // اطلاع‌رسانی به دیگران
-            //   In a loop, call in.readObject(), you can separate messages by their type:
+                    broadcastSystemMessage("[System] " + username + " joined the chat.");
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
+                }
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
+            } else {
-            //   Keep looping until the connection is closed (an exception will be thrown).
+                socket.close();
+                return;
+            }
+
+            // ۲. حلقه اصلی دریافت پکت‌ها
+            while (true) {
+                Object received = in.readObject();
+                if (received instanceof ChatMessage chatMsg) {
+                    handleChatMessage(chatMsg);
+                } else if (received instanceof FileMessage fileMsg) {
+                    handleFileMessage(fileMsg);
+                }
+            }
 
         } catch (Exception e) {
             System.out.println("Disconnected: " + username);
         } finally {
-            // TODO: Remove the user from UserManager so they no longer
+            // پاکسازی کاربر پس از خروج
-            //        receive broadcasts or appear in users list
+            if (username != null) {
+                userManager.removeUser(username);
+                broadcastSystemMessage("[System] " + username + " left the chat.");
+            }
+            try {
+                if (!socket.isClosed()) socket.close();
+            } catch (IOException ignored) {}
         }
     }
 
-
     private void handleChatMessage(ChatMessage msg) throws IOException {
         switch (msg.getType()) {
             case PUBLIC_MESSAGE -> {
-                // TODO: Broadcast this message to every connected client.
+                // ارسال پیام عمومی برای همه کاربران با چرخیدن روی تمام سشن‌ها
+                for (ClientSession session : userManager.getAllSessions()) {
+                    session.sendObject(msg);
+                }
             }
             case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
+                // پیدا کردن سشن گیرنده خصوصی و ارسال پکت
+                ClientSession targetSession = userManager.getUser(msg.getReceiver());
+                if (targetSession != null) {
+                    targetSession.sendObject(msg);
+                } else {
+                    // اگر کاربر آنلاین نبود، پیغام خطا به فرستنده برمی‌گردد
+                    sendObject(new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", username, "User " + msg.getReceiver() + " is offline."));
+                }
             }
             case USER_LIST -> {
-                // TODO: Reply to the requester with the list of online users.
+                // دریافت لیست متنی با متد تایید شده listUsers()
+                String onlineUsers = userManager.listUsers();
+                ChatMessage listReply = new ChatMessage(MessageType.USER_LIST, "Server", username, "Online users: " + onlineUsers);
+                sendObject(listReply);
             }
         }
     }
 
     private void handleFileMessage(FileMessage fileMsg) throws IOException {
-        // Storing the file
         var sentPath = FileManager.getSentPath(fileMsg.getSender(), fileMsg.getFilename());
         var recvPath = FileManager.getReceivedPath(fileMsg.getReceiver(), fileMsg.getFilename());
 
         Files.write(sentPath, fileMsg.getData());
         Files.write(recvPath, fileMsg.getData());
 
-        // TODO: Forward the received file-message to the destination user.
+        // فوروارد مستقیم فایل به دست سشن گیرنده مقصد
+        ClientSession targetSession = userManager.getUser(fileMsg.getReceiver());
+        if (targetSession != null) {
+            targetSession.sendObject(fileMsg);
+        }
+    }
+
+    // متد ترد-ایمن برای فرستادن آبجکت روی شبکه
+    public synchronized void sendObject(Object obj) throws IOException {
+        if (out != null) {
+            out.writeObject(obj);
+            out.flush();
+        }
+    }
+
+    // متد کمکی برودکست پیام‌های سیستمی ورود و خروج
+    private void broadcastSystemMessage(String content) {
+        ChatMessage sysMsg = new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", "All", content);
+        for (ClientSession session : userManager.getAllSessions()) {
+            try {
+                session.sendObject(sysMsg);
+            } catch (IOException ignored) {}
+        }
     }
 }