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

@@ -1,18 +1,38 @@
 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
+
-    //          (this should be the same input stream the
+    private final ObjectInputStream in;
-    //           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 msg = in.readObject();
-            //   - if it's a FileMessage  -> print that a file was received
+                if(msg instanceof ChatMessage chat){
-            //                               (filename + sender), it's already
+                    if (chat.getType() == MessageType.LOGIN_SUCCESS) {
-            //                               saved to disk by the server.
+                        System.out.println(" Login successful!");
+                    } else if (chat.getType() == MessageType.LOGIN_FAILED) {
+                        System.out.println(" Login failed: " + chat.getContent());
+                    } else if (chat.getSender().equals("Server")) {
+                        System.out.println("[Server]: " + chat.getContent());
+                    } else {
+                        System.out.println(chat.getSender() + ": " + chat.getContent());
+                    }
+                }else if(msg instanceof FileMessage file){
+                    System.out.println("File received: " + file.getFilename() + " from " + file.getSender());
+                }
+            }
         } catch (Exception e){
             System.out.println("Disconnected from server");
         }

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

@@ -1,29 +1,68 @@
 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
+import java.io.ObjectInputStream;
-        //  2. Create an ObjectOutputStream (out) and ObjectInputStream (in)
+import java.io.ObjectOutputStream;
-        //      from the socket's streams — output FIRST, then input.
+import java.net.Socket;
-        //  2. Get the username, and send a LOGIN ChatMessage with that username
+import java.nio.file.Files;
-        //  3. Start a new Thread running a ServerListener(in) so incoming
+import java.nio.file.Paths;
-        //      messages are handled concurrently.
+import java.util.Scanner;
 
-        while (true){
+public class chatClient {
-            try {
+
-                // TODO: Program loop — read a line from the console and act on it:
+    public static void main(String[] args) {
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+        try (Socket socket = new Socket("localhost", 12345)) {
-                //   - "/users"                    -> build & send a USER_LIST request
+
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+            Scanner scanner = new Scanner(System.in);
-                //                                     (you can use TransferProgress
+            System.out.println("Connected to server");
-                //                                     to show progress)
+
-                //                                     and send it as a FileMessage
+            ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
-                //   - anything else               -> send a PUBLIC_MESSAGE
+            out.flush();
-                //   Remember to flush() the output stream after writeObject().
+            ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
-            } catch (Exception e){
+
-                System.out.println("command failed: " + e.getMessage());
+
+            System.out.println("Enter username: ");
+            String username = scanner.nextLine().trim();
+
+            Thread listenerThread = new Thread(new ServerListener(in));
+            listenerThread.setDaemon(true);
+            listenerThread.start();
+
+            out.writeObject(new ChatMessage(MessageType.LOGIN, username, null, username));
+            out.flush();
+
+            Thread.sleep(300);
+
+            System.out.println("Login successful " + username);
+
+            while (true) {
+                String line = scanner.nextLine();
+
+                if (line.startsWith("/msg ")){
+                    String [] parts = line.split(" ", 3);
+                    if (parts.length == 3){
+                        out.writeObject(new ChatMessage(MessageType.PRIVATE_MESSAGE, username, parts[1], parts[2]));
+                        out.flush();
+                    }
+                }else if (line.equals("/users")){
+                    out.writeObject(new ChatMessage(MessageType.USER_LIST, username, null, null));
+                    out.flush();
+                }else if (line.startsWith("/sendfile ")){
+                    String [] parts = line.split(" ", 3);
+                    if (parts.length == 3){
+                        byte[] data = Files.readAllBytes(Paths.get(parts[2]));
+                        out.writeObject(new FileMessage(username, parts[1], Paths.get(parts[2]).getFileName().toString(), data));
+                        out.flush();
+                    }
+                }else{
+                    out.writeObject(new ChatMessage(MessageType.PUBLIC_MESSAGE, username, null, line));
+                    out.flush();
+                }
             }
+        } catch (Exception e){
+            System.out.println("command failed: " + e.getMessage());
         }
     }
 }

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

@@ -1,15 +1,20 @@
 package com.university.chat.Server;
 
+import java.net.ServerSocket;
+import java.net.Socket;
+
 public class ChatServer {
-    // TODO: declare a single shared UserManager instance (static final)
+    public static final UserManager userManager = new UserManager();
-    //         This MUST be shared by all ClientSession threads so that
-    //         broadcasting and private messaging work correctly.
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        try(ServerSocket serverSocket = new ServerSocket(12345)){
-
+            System.out.println("Server started on port 12345");
-        // TODO: In an infinite loop:
+            while (true){
-        //  accept an incoming client connection
+                Socket clientSocket = serverSocket.accept();
-        //  make a new thread running ClientSession for each user.
+                new Thread(new ClientSession(clientSocket, userManager)).start();
+            }
+        }catch (Exception e){
+            e.printStackTrace();
+        }
     }
 }

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

@@ -2,70 +2,115 @@ 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 String username;
+    private final Socket socket;
+    private final UserManager userManager;
+    private ObjectOutputStream out;
+    private ObjectInputStream in;
+    private boolean isLogeIn = false;
 
     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{
+            this.out = new ObjectOutputStream(socket.getOutputStream());
+            this.in = new ObjectInputStream(socket.getInputStream());
+        }catch (IOException e){
+            e.printStackTrace();
+        }
     }
 
     @Override
     public void run() {
         try {
+            ChatMessage loginMsg = (ChatMessage) in.readObject();
+            if(loginMsg.getType() == MessageType.LOGIN){
+                this.username = loginMsg.getContent();
+                if (userManager.addUser(username, this)){
+                    FileManager.createUserFolders(username);
+                    out.writeObject(new ChatMessage(MessageType.LOGIN_SUCCESS, "Server", null, "Welcome"));
+                    out.flush();
+                    isLogeIn = true;
+                    System.out.println("User logged in: " + username);
+                }else{
+                    out.writeObject(new ChatMessage(MessageType.LOGIN_FAILED, "Server", null, "User taken"));
+                    out.flush();
+                    socket.close();
+                    return;
+                }
+            }
 
-            // TODO: Welcome the user (login step)
+            while (true) {
-            //  1. Read the first object sent by the client.
+                Object obj = in.readObject();
-            //  2. Check it's a ChatMessage with type LOGIN.
+                if (obj instanceof ChatMessage)  handleChatMessage((ChatMessage) obj);
-            //  3. Extract the username.
+                else if (obj instanceof FileMessage)  handleFileMessage((FileMessage) obj);
-            //  4. Try to register the user via userManager.addUser(...).
+            }
-            //  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
-            //   In a loop, call in.readObject(), you can separate messages by their type:
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
-            //   Keep looping until the connection is closed (an exception will be thrown).
-
         } catch (Exception e) {
             System.out.println("Disconnected: " + username);
         } finally {
-            // TODO: Remove the user from UserManager so they no longer
+            if (username != null && userManager.getUser(username) == this){
-            //        receive broadcasts or appear in users list
+                userManager.removeUser(username);
-        }
+                System.out.println("User removed: " + username);
+            }
+            try {
+                if (socket != null && socket.isClosed()){
+                    socket.close();
+                }
+            } catch (IOException e) {}
+         }
     }
 
-
     private void handleChatMessage(ChatMessage msg) throws IOException {
         switch (msg.getType()) {
             case PUBLIC_MESSAGE -> {
-                // TODO: Broadcast this message to every connected client.
+                System.out.println("Broadcasting from " + msg.getSender());
+                for (ClientSession s : userManager.getAllSessions()){
+                    if(s != this && s.isLogeIn)  s.sendMessage(msg);
+                }
             }
             case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
+                System.out.println("Private message from " + msg.getSender() + "to " + msg.getReceiver());
+                ClientSession target = userManager.getUser(msg.getReceiver());
+                if(target != null && target != this && target.isLogeIn) {
+                    target.sendMessage(msg);
+                }else if(target == this){
+                    sendMessage(new ChatMessage(MessageType.PRIVATE_MESSAGE, "Server" , username, "You cannot message yourself"));
+                }else {
+                    sendMessage(new ChatMessage(MessageType.PRIVATE_MESSAGE, "Server" , username, "User not found: " +msg.getReceiver()));
+                }
             }
             case USER_LIST -> {
-                // TODO: Reply to the requester with the list of online users.
+                String usersList = String.join(", ", userManager.listUsers());
+                sendMessage(new ChatMessage(MessageType.USER_LIST, "Server", username, usersList));
             }
         }
     }
 
     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.
+        ClientSession target = userManager.getUser(fileMsg.getReceiver());
+        if (target != null && target.isLogeIn)  target.sendMessage(fileMsg);
+    }
+
+    public void sendMessage(Object msg) throws IOException{
+        if (out != null){
+            out.writeObject(msg);
+            out.flush();
+        }
     }
 }