Assignment-10

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

@@ -1,18 +1,32 @@
 package com.university.chat.Client;
 
+import com.university.chat.Common.ChatMessage;
+import com.university.chat.Common.FileMessage;
+
+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 receivedObject = in.readObject();
-            //   - if it's a FileMessage  -> print that a file was received
+
-            //                               (filename + sender), it's already
+                if (receivedObject instanceof ChatMessage) {
-            //                               saved to disk by the server.
+                    ChatMessage chatMsg = (ChatMessage) receivedObject;
+                    System.out.println(chatMsg.getSender() + ": " + chatMsg.getContent());
+                } else if (receivedObject instanceof FileMessage) {
+                    FileMessage fileMsg = (FileMessage) receivedObject;
+                    System.out.println("[System] File received: " + fileMsg.getFilename() +
+                            " sent by " + fileMsg.getSender() + ".");
+                }
+            }
         } catch (Exception e){
             System.out.println("Disconnected from server");
         }

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

@@ -1,26 +1,109 @@
 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.*;
+import java.net.Socket;
+import java.util.Scanner;
+
 public class chatClient {
-    public static void main() {
+    private static final String SERVER_HOST = "127.0.0.1";
-        // TODO: Connecting to the server
+    private static final int SERVER_PORT = 5000;
-        //  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;
-        //  3. Start a new Thread running a ServerListener(in) so incoming
+        ObjectOutputStream out;
-        //      messages are handled concurrently.
+        ObjectInputStream in;
+        String username;
+
+        try {
+            System.out.println("Connecting to server at " + SERVER_HOST + ":" + SERVER_PORT + "...");
+            socket = new Socket(SERVER_HOST, SERVER_PORT);
+
+            out = new ObjectOutputStream(socket.getOutputStream());
+            out.flush();
+            in = new ObjectInputStream(socket.getInputStream());
+
+            System.out.print("Enter your username: ");
+            username = scanner.nextLine().trim();
+
+            ChatMessage loginMsg = new ChatMessage(MessageType.LOGIN, username, "SERVER", "");
+            out.writeObject(loginMsg);
+            out.flush();
+
+            ServerListener listener = new ServerListener(in);
+            Thread listenerThread = new Thread(listener);
+            listenerThread.setDaemon(true);
+            listenerThread.start();
+
+            System.out.println("Logged in successfully! You can now type your message.");
+        } catch (IOException e) {
+            System.err.println("Could not connect to server: " + e.getMessage());
+            return;
+        }
 
         while (true){
             try {
-                // TODO: Program loop — read a line from the console and act on it:
+                String line = scanner.nextLine().trim();
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+                if (line.isEmpty()) continue;
-                //   - "/users"                    -> build & send a USER_LIST request
+
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+                if (line.startsWith("/msg")) {
-                //                                     (you can use TransferProgress
+                    String[] parts = line.split(" ", 3);
-                //                                     to show progress)
+                    if (parts.length < 3) {
-                //                                     and send it as a FileMessage
+                        System.out.println("Usage: /msg <username> <message>");
-                //   - anything else               -> send a PUBLIC_MESSAGE
+                        continue;
-                //   Remember to flush() the output stream after writeObject().
+                    }
+                    String receiver = parts[1];
+                    String message = parts[2];
+
+                    ChatMessage privateMsg = new ChatMessage(MessageType.PRIVATE_MESSAGE, username, receiver, message);
+                    out.writeObject(privateMsg);
+
+                    System.out.println("[To " + receiver + "]: " + message);
+
+                } else if (line.trim().equals("/users")) {
+                    ChatMessage listMsg = new ChatMessage(MessageType.USER_LIST, username, "SERVER", "");
+                    out.writeObject(listMsg);
+
+                } 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];
+
+                    File file = new File(filePath);
+                    if (!file.exists()) {
+                        System.out.println("File does not exist: " + filePath);
+                        continue;
+                    }
+
+                    long fileSize = file.length();
+                    byte[] fileData = new byte[(int) fileSize];
+
+                    try (FileInputStream fis = new FileInputStream(file)) {
+                        fis.read(fileData);
+                    }
+
+                    TransferProgress progress = new TransferProgress(fileSize);
+                    progress.update(fileSize);
+
+                    FileMessage fileMsg = new FileMessage(username, receiver, file.getName(), fileData);
+                    out.writeObject(fileMsg);
+                    System.out.println(file.getName() + " Sent successfully.");
+
+                } 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());
             }

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)
+    public static final UserManager userManager = new UserManager();
-    //         This MUST be shared by all ClientSession threads so that
+    private static final int PORT = 5000;
-    //         broadcasting and private messaging work correctly.
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        System.out.println("Initializing Chat Server on port " + PORT + "...");
 
-        // TODO: In an infinite loop:
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
-        //  accept an incoming client connection
+            System.out.println("Server successfully connected to port. Waiting for clients...");
-        //  make a new thread running ClientSession for each user.
+
+            while (true) {
+                try {
+                    Socket clientSocket = serverSocket.accept();
+                    System.out.println("Connection established with: " + clientSocket.getRemoteSocketAddress());
+
+                    ClientSession clientSession = new ClientSession(clientSocket, userManager);
+                    Thread sessionThread = new Thread(clientSession);
+                    sessionThread.start();
+                } catch (IOException e) {
+                    System.err.println("Failed to accept a specific client connection: " + e.getMessage());
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("Critical Server Error: Could not listen on port " + PORT);
+            System.err.println(e.getMessage());
+        }
     }
 }

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

@@ -2,70 +2,127 @@ 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 {
+            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 session: " + e.getMessage());
+        }
     }
 
     @Override
     public void run() {
         try {
+            Object firstObject = in.readObject();
 
-            // TODO: Welcome the user (login step)
+            if (firstObject instanceof ChatMessage loginMsg && loginMsg.getType() == MessageType.LOGIN) {
-            //  1. Read the first object sent by the client.
+                this.username = loginMsg.getSender();
-            //  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:
+                    FileManager.createUserFolders(username);
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
+                    sendMessage(new ChatMessage(MessageType.LOGIN_SUCCESS, "SERVER", username, "Login successful."));
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
+                    System.out.println("[Server] User logged in: " + username);
-            //   Keep looping until the connection is closed (an exception will be thrown).
+                } else {
+                    sendMessage(new ChatMessage(MessageType.LOGIN_FAILED, "SERVER", username, "Username is already taken."));
+                    socket.close();
+                    return;
+                }
+            } else {
+                socket.close();
+                return;
+            }
 
+            while (true) {
+                Object receivedObject = in.readObject();
+
+                if (receivedObject instanceof ChatMessage) {
+                    handleChatMessage((ChatMessage) receivedObject);
+                } else if (receivedObject instanceof FileMessage) {
+                    handleFileMessage((FileMessage) receivedObject);
+                }
+            }
         } 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
+                if (userManager.getUser(username) == this) {
+                    userManager.removeUser(username);
+                    System.out.println("[Server] Safely removed active user: " + username);
+                }
+            }
+            try {
+                socket.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
         }
     }
 
-
     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 recipient = userManager.getUser(msg.getReceiver());
+                if (recipient != null) {
+                    recipient.sendMessage(msg);
+                } else {
+                    sendMessage(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.
+                String activeUsers = userManager.listUsers();
+                ChatMessage listMsg = new ChatMessage(MessageType.USER_LIST, "SERVER", username, activeUsers);
+                sendMessage(listMsg);
             }
+            default -> System.out.println("Unknown ChatMessage type received.");
         }
     }
 
     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 recipient = userManager.getUser(fileMsg.getReceiver());
+        if (recipient != null) {
+            recipient.sendMessage(fileMsg);
+        }
+    }
+
+    public synchronized void sendMessage(Object msg) {
+        try {
+            if (out != null) {
+                out.writeObject(msg);
+                out.flush();
+            }
+        } catch (IOException e) {
+            System.err.println("Failed to send packet to " + username + ": " + e.getMessage());
+        }
     }
 }