HW-10-last-edition

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

@@ -1,19 +1,35 @@
 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
+import com.university.chat.Common.MessageType;
-    //           chatClient created when connecting)
+
+import java.io.ObjectInputStream;
+
+public class ServerListener implements Runnable {
+
+    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
+            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
+                if (obj instanceof ChatMessage msg) {
-            //                               (filename + sender), it's already
+                    if (msg.getType() == MessageType.USER_LIST) {
-            //                               saved to disk by the server.
+                        System.out.println("[Online users] " + msg.getContent());
-        } catch (Exception e){
+                    } else {
+                        System.out.println(msg.getSender() + ": " + msg.getContent());
+                    }
+                } else if (obj instanceof FileMessage fileMsg) {
+                    System.out.println("[File received] '" + fileMsg.getFilename() + "' from " + fileMsg.getSender());
+                }
+            }
+        } catch (Exception e) {
             System.out.println("Disconnected from server");
         }
     }

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

@@ -1,29 +1,121 @@
 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.FileInputStream;
-            try {
+import java.io.ObjectInputStream;
-                // TODO: Program loop — read a line from the console and act on it:
+import java.io.ObjectOutputStream;
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+import java.net.Socket;
-                //   - "/users"                    -> build & send a USER_LIST request
+import java.nio.file.Files;
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+import java.nio.file.Path;
-                //                                     (you can use TransferProgress
+import java.nio.file.Paths;
-                //                                     to show progress)
+import java.util.Scanner;
-                //                                     and send it as a FileMessage
+
-                //   - anything else               -> send a PUBLIC_MESSAGE
+public class chatClient {
-                //   Remember to flush() the output stream after writeObject().
+
-            } catch (Exception e){
+    private static final String SERVER_HOST = "localhost";
-                System.out.println("command failed: " + e.getMessage());
+    private static final int SERVER_PORT = 12345;
+
+    public static void main(String[] args) {
+        try {
+            Socket socket = new Socket(SERVER_HOST, SERVER_PORT);
+
+            // Output stream MUST come first on both ends to avoid handshake deadlock
+            ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
+
+            Scanner scanner = new Scanner(System.in);
+            System.out.print("Enter username: ");
+            String username = scanner.nextLine().trim();
+
+            out.writeObject(new ChatMessage(MessageType.LOGIN, username, null, null));
+            out.flush();
+
+            // Wait for login response before starting the listener
+            Object resp = in.readObject();
+            if (resp instanceof ChatMessage loginResp) {
+                if (loginResp.getType() == MessageType.LOGIN_FAILED) {
+                    System.out.println("Login failed: " + loginResp.getContent());
+                    socket.close();
+                    return;
+                }
+                System.out.println(loginResp.getContent());
             }
+
+            // Listener thread handles all incoming messages from now on
+            Thread listener = new Thread(new ServerListener(in));
+            listener.setDaemon(true);
+            listener.start();
+
+            System.out.println("Commands: /msg <user> <text> | /users | /sendfile <user> <path> | <text>");
+
+            while (true) {
+                try {
+                    String line = scanner.nextLine();
+
+                    if (line.startsWith("/msg ")) {
+                        String[] parts = line.split(" ", 3);
+                        if (parts.length < 3) {
+                            System.out.println("Usage: /msg <user> <text>");
+                            continue;
+                        }
+                        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) {
+                            System.out.println("Usage: /sendfile <user> <path>");
+                            continue;
+                        }
+                        String targetUser = parts[1];
+                        Path filePath = Paths.get(parts[2]);
+
+                        if (!Files.exists(filePath)) {
+                            System.out.println("File not found: " + filePath);
+                            continue;
+                        }
+
+                        long fileSize = Files.size(filePath);
+                        byte[] fileData = new byte[(int) fileSize];
+                        TransferProgress progress = new TransferProgress(fileSize);
+
+                        // Read file in chunks so the progress bar actually updates
+                        try (FileInputStream fis = new FileInputStream(filePath.toFile())) {
+                            int bytesRead = 0;
+                            byte[] buffer = new byte[8192];
+                            int chunk;
+                            while ((chunk = fis.read(buffer)) != -1) {
+                                System.arraycopy(buffer, 0, fileData, bytesRead, chunk);
+                                bytesRead += chunk;
+                                progress.update(bytesRead);
+                            }
+                        }
+
+                        String filename = filePath.getFileName().toString();
+                        out.writeObject(new FileMessage(username, targetUser, filename, fileData));
+                        out.flush();
+                        System.out.println("Sent '" + filename + "' to " + targetUser);
+
+                    } 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("Failed to connect to server: " + e.getMessage());
         }
     }
 }

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

@@ -1,15 +1,25 @@
 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)
+
-    //         This MUST be shared by all ClientSession threads so that
+    private static final int PORT = 12345;
-    //         broadcasting and private messaging work correctly.
+    private static final UserManager userManager = new UserManager();
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        System.out.println("Chat server started on port " + PORT);
-
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
-        // 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.
+                System.out.println("New connection from " + clientSocket.getInetAddress());
+                Thread thread = new Thread(new ClientSession(clientSocket, userManager));
+                thread.start();
+            }
+        } catch (IOException e) {
+            System.out.println("Server error: " + e.getMessage());
+        }
     }
 }

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

@@ -2,70 +2,124 @@ 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;
 
     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 come first on both ends to avoid handshake deadlock
+            out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            in = new ObjectInputStream(socket.getInputStream());
+        } catch (IOException e) {
+            System.out.println("Error setting up streams: " + e.getMessage());
+        }
     }
 
     @Override
     public void run() {
         try {
+            // Login step
+            Object firstObj = in.readObject();
+            if (!(firstObj instanceof ChatMessage loginMsg) || loginMsg.getType() != MessageType.LOGIN) {
+                socket.close();
+                return;
+            }
 
-            // TODO: Welcome the user (login step)
+            username = loginMsg.getSender();
-            //  1. Read the first object sent by the client.
-            //  2. Check it's a ChatMessage with type LOGIN.
-            //  3. Extract the username.
-            //  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
+            if (!userManager.addUser(username, this)) {
-            //   In a loop, call in.readObject(), you can separate messages by their type:
+                sendMessage(new ChatMessage(MessageType.LOGIN_FAILED, "Server", username, "Username already taken."));
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
+                socket.close();
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
+                return;
-            //   Keep looping until the connection is closed (an exception will be thrown).
+            }
+
+            FileManager.createUserFolders(username);
+            sendMessage(new ChatMessage(MessageType.LOGIN_SUCCESS, "Server", username, "Welcome, " + username + "!"));
+            System.out.println(username + " logged in.");
+
+            // 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);
         } finally {
-            // TODO: Remove the user from UserManager so they no longer
+            if (username != null) {
-            //        receive broadcasts or appear in users list
+                userManager.removeUser(username);
+            }
+            try {
+                socket.close();
+            } catch (IOException ignored) {}
         }
     }
 
+    // synchronized so concurrent broadcast calls don't interleave bytes on the stream
+    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()) {
+                    try {
+                        session.sendMessage(msg);
+                    } catch (IOException e) {
+                        System.out.println("Failed to deliver to " + session.username);
+                    }
+                }
             }
             case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
+                ClientSession receiver = userManager.getUser(msg.getReceiver());
+                if (receiver != null) {
+                    receiver.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.
+                sendMessage(new ChatMessage(MessageType.USER_LIST, "Server", username, userManager.listUsers()));
             }
         }
     }
 
     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 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 was saved locally."));
+        }
     }
-}
+}