implementation of HW-10 is complete

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

@@ -1,20 +1,40 @@
 package com.university.chat.Client;
 
+import com.university.chat.Common.ChatMessage;
+import com.university.chat.Common.FileMessage;
+import com.university.chat.Common.MessageType;
+
+import java.io.ObjectInputStream;
+
 public class ServerListener implements Runnable{
-    // TODO: store the ObjectInputStream from the user socket
+    private final ObjectInputStream in;
-    //          (this should be the same input stream the
+
-    //           chatClient created when connecting)
+    public ServerListener(ObjectInputStream in) {
+        this.in = in;
+    }
 
     @Override
     public void run() {
         try {
-            // TODO: In an infinite loop read objects from the server
+            while (true) {
-            //   - if it's a ChatMessage  -> print "<sender>: <content>"
+                Object obj = in.readObject();
-            //   - if it's a FileMessage  -> print that a file was received
+
-            //                               (filename + sender), it's already
+                if (obj instanceof ChatMessage msg) {
-            //                               saved to disk by the server.
+                    if (msg.getType() == MessageType.USER_LIST) {
+                        System.out.println("\n[Online Users]: " + msg.getContent());
+                    } else if (msg.getType() == MessageType.PRIVATE_MESSAGE) {
+                        System.out.println("\n[Private] " + msg.getSender() + ": " + msg.getContent());
+                    } else {
+                        System.out.println("\n" + msg.getSender() + ": " + msg.getContent());
+                    }
+                } else if (obj instanceof FileMessage fileMsg) {
+                    System.out.println("\n[File Received] Filename: '" + fileMsg.getFilename() +
+                            "' sent by " + fileMsg.getSender() + ". It is saved on the server disk.");
+                }
+                System.out.print("> "); // Keep a prompt symbol for console usability
+            }
         } catch (Exception e) {
-            System.out.println("Disconnected from server");
+            System.out.println("\nDisconnected from server.");
         }
     }
 }

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

@@ -1,28 +1,154 @@
 package com.university.chat.Client;
 
+import com.university.chat.Common.ChatMessage;
+import com.university.chat.Common.FileMessage;
+import com.university.chat.Common.MessageType;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.Socket;
+import java.util.Scanner;
+
 public class chatClient {
-    public static void main() {
+    private static final String SERVER_HOST = "localhost";
-        // TODO: Connecting to the server
+    private static final int SERVER_PORT = 12345;
-        //  1. Create a socket and connect to the server
+
-        //  2. Create an ObjectOutputStream (out) and ObjectInputStream (in)
+    public static void main(String[] args) {
-        //      from the socket's streams — output FIRST, then input.
+        Scanner scanner = new Scanner(System.in);
-        //  2. Get the username, and send a LOGIN ChatMessage with that username
+        Socket socket = null;
-        //  3. Start a new Thread running a ServerListener(in) so incoming
+        ObjectOutputStream out = null;
-        //      messages are handled concurrently.
+        ObjectInputStream in = null;
+        String username = "";
+
+        try {
+            System.out.print("Enter your username: ");
+            username = scanner.nextLine().trim();
+
+            if (username.isEmpty()) {
+                System.out.println("Username cannot be blank. Exiting...");
+                return;
+            }
+
+            // 1. Create socket connection
+            socket = new Socket(SERVER_HOST, SERVER_PORT);
+
+            // 2. Setup Object streams — Output stream FIRST to avoid deadlocking handshake
+            out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            in = new ObjectInputStream(socket.getInputStream());
+
+            // 3. Authenticate with LOGIN message
+            ChatMessage loginMsg = new ChatMessage(MessageType.LOGIN, username, "Server", "");
+            out.writeObject(loginMsg);
+            out.flush();
+
+            // Wait for Server to validate
+            Object response = in.readObject();
+            if (response instanceof ChatMessage reply) {
+                if (reply.getType() == MessageType.LOGIN_FAILED) {
+                    System.out.println("Login Failed: " + reply.getContent());
+                    socket.close();
+                    return;
+                } else if (reply.getType() == MessageType.LOGIN_SUCCESS) {
+                    System.out.println("System: Connected successfully! " + reply.getContent());
+                }
+            }
+
+            // 4. Start listening thread for concurrent receipt
+            Thread listenerThread = new Thread(new ServerListener(in));
+            listenerThread.setDaemon(true);
+            listenerThread.start();
+
+            // 5. Main loop for typing interactive user input
+            System.out.println("Use standard messages to chat. Commands:\n/msg <user> <message>\n/users\n/sendfile <user> <filepath>\n");
 
             while (true) {
+                String input = scanner.nextLine();
+                if (input.equalsIgnoreCase("/exit")) {
+                    System.out.println("Exiting chat...");
+                    break;
+                }
+
+                if (input.trim().isEmpty()) {
+                    continue;
+                }
+
                 try {
-                // TODO: Program loop — read a line from the console and act on it:
+                    if (input.startsWith("/msg ")) {
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+                        // Pattern: /msg <username> <message>
-                //   - "/users"                    -> build & send a USER_LIST request
+                        String[] parts = input.substring(5).split(" ", 2);
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+                        if (parts.length < 2) {
-                //                                     (you can use TransferProgress
+                            System.out.println("Usage: /msg <username> <message>");
-                //                                     to show progress)
+                            continue;
-                //                                     and send it as a FileMessage
+                        }
-                //   - anything else               -> send a PUBLIC_MESSAGE
+                        String recipient = parts[0];
-                //   Remember to flush() the output stream after writeObject().
+                        String text = parts[1];
+                        ChatMessage privateMsg = new ChatMessage(MessageType.PRIVATE_MESSAGE, username, recipient, text);
+                        out.writeObject(privateMsg);
+                        out.flush();
+
+                    } else if (input.equalsIgnoreCase("/users")) {
+                        ChatMessage listRequest = new ChatMessage(MessageType.USER_LIST, username, "Server", "");
+                        out.writeObject(listRequest);
+                        out.flush();
+
+                    } else if (input.startsWith("/sendfile ")) {
+                        // Pattern: /sendfile <username> <filepath>
+                        String[] parts = input.substring(10).split(" ", 2);
+                        if (parts.length < 2) {
+                            System.out.println("Usage: /sendfile <username> <filepath>");
+                            continue;
+                        }
+                        String recipient = parts[0];
+                        String filepath = parts[1];
+
+                        File file = new File(filepath);
+                        if (!file.exists() || !file.isFile()) {
+                            System.out.println("Error: File " + filepath + " does not exist.");
+                            continue;
+                        }
+
+                        // Load and read the file with a visual progress bar
+                        byte[] fileBytes = new byte[(int) file.length()];
+                        try (FileInputStream fis = new FileInputStream(file)) {
+                            TransferProgress progress = new TransferProgress(file.length());
+                            int bytesRead;
+                            int totalRead = 0;
+                            byte[] buffer = new byte[4096];
+
+                            while ((bytesRead = fis.read(buffer)) != -1) {
+                                System.arraycopy(buffer, 0, fileBytes, totalRead, bytesRead);
+                                totalRead += bytesRead;
+                                progress.update(totalRead);
+                            }
+                        }
+
+                        FileMessage fileMsg = new FileMessage(username, recipient, file.getName(), fileBytes);
+                        out.writeObject(fileMsg);
+                        out.flush();
+                        System.out.println("File sent successfully!");
+
+                    } else {
+                        // Treat as plain text PUBLIC message
+                        ChatMessage publicMsg = new ChatMessage(MessageType.PUBLIC_MESSAGE, username, "All", input);
+                        out.writeObject(publicMsg);
+                        out.flush();
+                    }
                 } catch (Exception e) {
-                System.out.println("command failed: " + e.getMessage());
+                    System.out.println("Command failed: " + e.getMessage());
+                }
+            }
+
+        } catch (Exception e) {
+            System.err.println("Fatal connection exception: " + e.getMessage());
+        } finally {
+            scanner.close();
+            try {
+                if (socket != null && !socket.isClosed()) socket.close();
+            } catch (Exception e) {
+                // Ignore silent close exceptions
             }
         }
     }

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

@@ -1,15 +1,34 @@
 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)
+    private static final UserManager userManager = new UserManager();
-    //         This MUST be shared by all ClientSession threads so that
+    private static final int PORT = 12345; // Default port
-    //         broadcasting and private messaging work correctly.
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        System.out.println("Starting Chat Server on port " + PORT + "...");
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
+            System.out.println("Server started successfully. Waiting for clients...");
 
-        // TODO: In an infinite loop:
+            while (true) {
-        //  accept an incoming client connection
+                try {
-        //  make a new thread running ClientSession for each user.
+
+                    Socket clientSocket = serverSocket.accept();
+                    System.out.println("New client connection from: " + clientSocket.getRemoteSocketAddress());
+
+                    // Create a new ClientSession task and run it in its own thread
+                    ClientSession session = new ClientSession(clientSocket, userManager);
+                    Thread clientThread = new Thread(session);
+                    clientThread.start();
+                } catch (IOException e) {
+                    System.err.println("Error accepting client connection: " + e.getMessage());
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("Could not listen on port " + PORT + ": " + e.getMessage());
+        }
     }
 }

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

@@ -2,70 +2,164 @@ 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 {
+            // Output stream MUST be created first to prevent 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 for client: " + e.getMessage());
+            closeResources();
+        }
     }
 
     @Override
     public void run() {
+        if (in == null || out == null) {
+            return;
+        }
+
         try {
+            // 1. Welcome the user (login step)
+            Object firstObj = in.readObject();
+            if (!(firstObj instanceof ChatMessage loginMsg) || loginMsg.getType() != MessageType.LOGIN) {
+                sendDirect(new ChatMessage(MessageType.LOGIN_FAILED, "Server", "", "Invalid connection sequence."));
+                closeResources();
+                return;
+            }
 
-            // TODO: Welcome the user (login step)
+            this.username = loginMsg.getSender();
-            //  1. Read the first object sent by the client.
+            if (this.username == null || this.username.trim().isEmpty()) {
-            //  2. Check it's a ChatMessage with type LOGIN.
+                sendDirect(new ChatMessage(MessageType.LOGIN_FAILED, "Server", "", "Username cannot be empty."));
-            //  3. Extract the username.
+                closeResources();
-            //  4. Try to register the user via userManager.addUser(...).
+                return;
-            //  5. If the username is taken, send back LOGIN_FAILED and close the socket.
+            }
-            //  6. Otherwise, create the user's folders with FileManager.createUserFolders(...)
-            //      and send back LOGIN_SUCCESS.
 
-            // TODO: Main message loop
+            // 2. Register user
-            //   In a loop, call in.readObject(), you can separate messages by their type:
+            if (!userManager.addUser(this.username, this)) {
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
+                sendDirect(new ChatMessage(MessageType.LOGIN_FAILED, "Server", this.username, "Username already taken."));
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
+                closeResources();
-            //   Keep looping until the connection is closed (an exception will be thrown).
+                return;
+            }
+
+            // 3. Setup workspace & approve login
+            FileManager.createUserFolders(this.username);
+            sendDirect(new ChatMessage(MessageType.LOGIN_SUCCESS, "Server", this.username, "Welcome to the chat!"));
+            System.out.println("User online: " + this.username);
+
+            //
+            broadcast(new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", "All", this.username + " has joined the chat."));
+
+            // 4. Main message loop
+            while (true) {
+                Object obj = in.readObject();
+                if (obj instanceof ChatMessage msg) {
+                    handleChatMessage(msg);
+                } else if (obj instanceof FileMessage fileMsg) {
+                    handleFileMessage(fileMsg);
+                }
+            }
 
         } catch (Exception e) {
-            System.out.println("Disconnected: " + username);
+            System.out.println("Disconnected: " + (username != null ? username : "Unknown client"));
         } finally {
-            // TODO: Remove the user from UserManager so they no longer
+            cleanup();
-            //        receive broadcasts or appear in users list
         }
     }
 
-
     private void handleChatMessage(ChatMessage msg) throws IOException {
         switch (msg.getType()) {
-            case PUBLIC_MESSAGE -> {
+            case PUBLIC_MESSAGE -> broadcast(msg);
-                // TODO: Broadcast this message to every connected client.
-            }
             case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
+                ClientSession recipient = userManager.getUser(msg.getReceiver());
+                if (recipient != null) {
+                    recipient.sendDirect(msg);
+                } else {
+                    sendDirect(new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", this.username, "User " + msg.getReceiver() + " is offline."));
+                }
             }
             case USER_LIST -> {
-                // TODO: Reply to the requester with the list of online users.
+                String users = userManager.listUsers();
+                sendDirect(new ChatMessage(MessageType.USER_LIST, "Server", this.username, users));
             }
+            default -> {}
         }
     }
 
     private void handleFileMessage(FileMessage fileMsg) throws IOException {
-        // Storing the file
+        // Storing the file on the server side
         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.
+        // Forward the received file-message to the destination user.
+        ClientSession recipient = userManager.getUser(fileMsg.getReceiver());
+        if (recipient != null) {
+            recipient.sendDirect(fileMsg);
+        } else {
+            sendDirect(new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", this.username, "Could not deliver file. User " + fileMsg.getReceiver() + " is offline."));
+        }
+    }
+
+    // Helper to send directly to this session's socket
+    public synchronized void sendDirect(Object obj) {
+        try {
+            out.writeObject(obj);
+            out.flush();
+        } catch (IOException e) {
+            System.err.println("Error sending message to " + username + ": " + e.getMessage());
+        }
+    }
+
+    // Broadcasts to all users except sender
+    private void broadcast(ChatMessage msg) {
+        for (ClientSession session : userManager.getAllSessions()) {
+            if (!session.getUsername().equals(this.username)) {
+                session.sendDirect(msg);
+            }
+        }
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    private void cleanup() {
+        if (username != null) {
+            userManager.removeUser(username);
+            broadcast(new ChatMessage(MessageType.PUBLIC_MESSAGE, "Server", "All", username + " has left the chat."));
+        }
+        closeResources();
+    }
+
+    private void closeResources() {
+        try {
+            if (in != null) in.close();
+            if (out != null) out.close();
+            if (socket != null && !socket.isClosed()) socket.close();
+        } catch (IOException e) {
+            System.err.println("Error closing resources: " + e.getMessage());
+        }
     }
 }

test.txt

@@ -0,0 +1 @@
+salammmmmm.