.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_23" project-jdk-name="23 (2)" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

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

@@ -1,10 +1,21 @@
 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
     //           chatClient created when connecting)
 
+    private final ObjectInputStream in;
+
+    public ServerListener(ObjectInputStream in) {
+        this.in = in;
+    }
     @Override
     public void run() {
         try {
@@ -13,8 +24,44 @@ public class ServerListener implements Runnable{
             //   - if it's a FileMessage  -> print that a file was received
             //                               (filename + sender), it's already
             //                               saved to disk by the server.
+            while (true) {
+                Object obj = in.readObject();
+
+                if (obj instanceof ChatMessage msg) {
+                    handleChatMessage(msg);
+                } else if (obj instanceof FileMessage fileMsg) {
+                    System.out.println("\n[File received] '" + fileMsg.getFilename()
+                            + "' from " + fileMsg.getSender()
+                            + " (saved to your received folder).");
+                }
+            }
         } catch (Exception e){
             System.out.println("Disconnected from server");
         }
     }
+
+    private void handleChatMessage(ChatMessage msg) {
+        switch (msg.getType()) {
+            case LOGIN_SUCCESS ->
+                    System.out.println("[Server] " + msg.getContent());
+
+            case LOGIN_FAILED -> {
+                System.out.println("[Server] Login failed: " + msg.getContent());
+                System.exit(1);
+            }
+
+            case PUBLIC_MESSAGE ->
+                    System.out.println("[Public] " + msg.getSender() + ": " + msg.getContent());
+
+            case PRIVATE_MESSAGE ->
+                    System.out.println("[Private] " + msg.getSender() + " -> " + msg.getReceiver()
+                            + ": " + msg.getContent());
+
+            case USER_LIST ->
+                    System.out.println("[Online users] " + msg.getContent());
+
+            default ->
+                    System.out.println("[Server] " + msg.getContent());
+        }
+    }
 }

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

@@ -1,7 +1,22 @@
 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.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.Socket;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
 public class chatClient {
-    public static void main() {
+    private static final String SERVER_HOST = "localhost";
+    private static final int SERVER_PORT = 12345;
+
+    public static void main(String[] args) {
         // TODO: Connecting to the server
         //  1. Create a socket and connect to the server
         //  2. Create an ObjectOutputStream (out) and ObjectInputStream (in)
@@ -9,7 +24,24 @@ public class chatClient {
         //  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.
+        BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
 
+        try {
+            Socket socket = new Socket(SERVER_HOST, SERVER_PORT);
+            System.out.println("Connected to server at " + SERVER_HOST + ":" + SERVER_PORT);
+            ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
+            System.out.print("Enter your username: ");
+            String username = console.readLine().trim();
+
+            out.writeObject(new ChatMessage(MessageType.LOGIN, username, null, null));
+            out.flush();
+            Thread listenerThread = new Thread(new ServerListener(in));
+            listenerThread.setDaemon(true);
+            listenerThread.start();
+
+            System.out.println("Commands:  /msg <user> <text>  |  /users  |  /sendfile <user> <path>");
         while (true){
             try {
                 // TODO: Program loop — read a line from the console and act on it:
@@ -21,9 +53,67 @@ public class chatClient {
                 //                                     and send it as a FileMessage
                 //   - anything else               -> send a PUBLIC_MESSAGE
                 //   Remember to flush() the output stream after writeObject().
-            } catch (Exception e){
+                String line = console.readLine();
+                if (line == null) break;
+
+                line = line.trim();
+                if (line.isEmpty()) continue;
+
+                if (line.startsWith("/msg ")) {
+                    String[] parts = line.split(" ", 3);
+                    if (parts.length < 3) {
+                        System.out.println("Usage: /msg <username> <message>");
+                        continue;
+                    }
+                    String receiver = parts[1];
+                    String text = parts[2];
+                    out.writeObject(new ChatMessage(
+                            MessageType.PRIVATE_MESSAGE, username, receiver, text));
+                    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) {
+                        System.out.println("Usage: /sendfile <username> <filepath>");
+                        continue;
+                    }
+                    String receiver = parts[1];
+                    String filepath = parts[2];
+
+                    var path = Paths.get(filepath);
+                    if (!Files.exists(path)) {
+                        System.out.println("File not found: " + filepath);
+                        continue;
+                    }
+
+                    byte[] fileData = Files.readAllBytes(path);
+                    String filename = path.getFileName().toString();
+
+                    TransferProgress progress = new TransferProgress(fileData.length);
+                    progress.update(fileData.length); // single-shot since it's already in memory
+
+                    out.writeObject(new FileMessage(username, receiver, filename, fileData));
+                    out.flush();
+                    System.out.println("File '" + filename + "' sent to " + receiver + ".");
+
+                } else {
+                    out.writeObject(new ChatMessage(
+                            MessageType.PUBLIC_MESSAGE, username, null, line));
+                    out.flush();
+                }
+        } catch (Exception e){
                 System.out.println("command failed: " + e.getMessage());
             }
         }
+
+        } catch (Exception e) {
+            System.out.println("Could not connect to server: " + e.getMessage());
+        }
     }
 }
+

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

@@ -1,15 +1,36 @@
 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)
     //         This MUST be shared by all ClientSession threads so that
     //         broadcasting and private messaging work correctly.
 
+    private static final int PORT = 12345;
+    private static final UserManager userManager = new UserManager();
+
     public static void main(String[] args) {
         // TODO: Create a ServerSocket
 
         // TODO: In an infinite loop:
         //  accept an incoming client connection
         //  make a new thread running ClientSession for each user.
+        System.out.println("Server starting on port " + PORT + "...");
+
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
+            System.out.println("Server is listening for connections.");
+
+            while (true) {
+                Socket clientSocket = serverSocket.accept();
+                System.out.println("New client connected: " + clientSocket.getInetAddress());
+
+                ClientSession session = new ClientSession(clientSocket, userManager);
+                Thread thread = new Thread(session);
+                thread.start();
+            }
+
+        } catch (Exception e) {
+            System.out.println("Server error: " + e.getMessage());
+        }
     }
 }

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

@@ -2,19 +2,36 @@ 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.net.Socket;
 import java.nio.file.Files;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
 
 public class ClientSession implements Runnable {
 
     private String username;
+    private final Socket socket;
+    private final UserManager userManager;
+    private ObjectOutputStream out;
+    private ObjectInputStream in;
 
     public ClientSession(Socket socket, UserManager userManager) {
         // TODO : Create an ObjectOutputStream from socket.getOutputStream()
         //         and an ObjectInputStream from socket.getInputStream().
-    }
+        this.socket = socket;
+        this.userManager = userManager;
+        try {
+            this.out = new ObjectOutputStream(socket.getOutputStream());
+            this.out.flush();
+            this.in = new ObjectInputStream(socket.getInputStream());
+        } catch (IOException e) {
+            System.out.println("Failed to set up streams: " + e.getMessage());
+        }
+}
 
     @Override
     public void run() {
@@ -34,32 +51,87 @@ public class ClientSession implements Runnable {
             //     - 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).
+            Object firstObject = in.readObject();
+
+            if (!(firstObject instanceof ChatMessage loginMsg)
+                    || loginMsg.getType() != MessageType.LOGIN) {
+                socket.close();
+                return;
+            }
+
+            username = loginMsg.getSender();
+
+            if (!userManager.addUser(username, this)) {
+                sendMessage(new ChatMessage(
+                        MessageType.LOGIN_FAILED, "Server", username,
+                        "Username '" + username + "' is already taken. Please reconnect with a different name."));
+                socket.close();
+                return;
+            }
+
+            FileManager.createUserFolders(username);
+            sendMessage(new ChatMessage(
+                    MessageType.LOGIN_SUCCESS, "Server", username,
+                    "Welcome, " + username + "! You are now connected."));
+
+            System.out.println(username + " logged in.");
+            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);
         } finally {
             // TODO: Remove the user from UserManager so they no longer
             //        receive broadcasts or appear in users list
+            if (username != null) {
+                userManager.removeUser(username);
+                System.out.println(username + " removed from user list.");
+            }
+            try { socket.close(); } catch (IOException ignored) {}
         }
     }
-
+    public synchronized void sendMessage(Object obj) throws IOException {
-
+        out.writeObject(obj);
+        out.flush();
+    }
     private void handleChatMessage(ChatMessage msg) throws IOException {
         switch (msg.getType()) {
             case PUBLIC_MESSAGE -> {
                 // TODO: Broadcast this message to every connected client.
+                for (ClientSession session : userManager.getAllSessions()) {
+                    session.sendMessage(msg);
+                }
             }
             case PRIVATE_MESSAGE -> {
                 // TODO: Forward this message to the receiver user.
+
+                ClientSession receiver = userManager.getUser(msg.getReceiver());
+                if (receiver != null) {
+                    receiver.sendMessage(msg);
+                    sendMessage(msg);
+                } else {
+                    sendMessage(new ChatMessage(
+                            MessageType.PUBLIC_MESSAGE, "Server", username,
+                            "User '" + msg.getReceiver() + "' is not online."));
+                }
             }
             case USER_LIST -> {
                 // TODO: Reply to the requester with the list of online users.
+                String userList = userManager.listUsers();
+                sendMessage(new ChatMessage(
+                        MessageType.USER_LIST, "Server", username, userList));
             }
         }
     }
 
     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());
 
@@ -67,5 +139,13 @@ public class ClientSession implements Runnable {
         Files.write(recvPath, fileMsg.getData());
 
         // TODO: Forward the received file-message to the destination user.
-    }
+        ClientSession receiver = userManager.getUser(fileMsg.getReceiver());
+        if (receiver != null) {
+            receiver.sendMessage(fileMsg);
+        } else {
+            sendMessage(new ChatMessage(
+                    MessageType.PUBLIC_MESSAGE, "Server", username,
+                    "User '" + fileMsg.getReceiver() + "' is not online. File not delivered."));
+        }
+        }
 }