Sharing chat System

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

@@ -1,20 +0,0 @@
-package com.university.chat.Client;
-
-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)
-
-    @Override
-    public void run() {
-        try {
-            // TODO: In an infinite loop read objects from the server
-            //   - if it's a ChatMessage  -> print "<sender>: <content>"
-            //   - if it's a FileMessage  -> print that a file was received
-            //                               (filename + sender), it's already
-            //                               saved to disk by the server.
-        } catch (Exception e){
-            System.out.println("Disconnected from server");
-        }
-    }
-}

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

@@ -1,29 +0,0 @@
-package com.university.chat.Client;
-
-public class chatClient {
-    public static void main() {
-        // TODO: Connecting to the server
-        //  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){
-            try {
-                // TODO: Program loop — read a line from the console and act on it:
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
-                //   - "/users"                    -> build & send a USER_LIST request
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
-                //                                     (you can use TransferProgress
-                //                                     to show progress)
-                //                                     and send it as a FileMessage
-                //   - anything else               -> send a PUBLIC_MESSAGE
-                //   Remember to flush() the output stream after writeObject().
-            } catch (Exception e){
-                System.out.println("command failed: " + e.getMessage());
-            }
-        }
-    }
-}

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

@@ -1,15 +0,0 @@
-package com.university.chat.Server;
-
-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.
-
-    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.
-    }
-}

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

@@ -1,71 +0,0 @@
-package com.university.chat.Server;
-
-import com.university.chat.Common.ChatMessage;
-import com.university.chat.Common.FileMessage;
-
-import java.io.IOException;
-import java.net.Socket;
-import java.nio.file.Files;
-
-public class ClientSession implements Runnable {
-
-    private String username;
-
-    public ClientSession(Socket socket, UserManager userManager) {
-        // TODO : Create an ObjectOutputStream from socket.getOutputStream()
-        //         and an ObjectInputStream from socket.getInputStream().
-    }
-
-    @Override
-    public void run() {
-        try {
-
-            // TODO: Welcome the user (login step)
-            //  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
-            //   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
-            //        receive broadcasts or appear in users list
-        }
-    }
-
-
-    private void handleChatMessage(ChatMessage msg) throws IOException {
-        switch (msg.getType()) {
-            case PUBLIC_MESSAGE -> {
-                // TODO: Broadcast this message to every connected client.
-            }
-            case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
-            }
-            case USER_LIST -> {
-                // TODO: Reply to the requester with the list of online users.
-            }
-        }
-    }
-
-    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.
-    }
-}

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

@@ -0,0 +1,44 @@
+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
+{
+    private ObjectInputStream in;
+
+    public ServerListener(ObjectInputStream in) {this.in = in;}
+
+    @Override
+    public void run()
+    {
+        try
+        {
+            while (true)
+            {
+                Object obj = in.readObject();
+
+                if (obj instanceof ChatMessage)
+                {
+                    ChatMessage msg = (ChatMessage) obj;
+
+                    String sender = msg.getSender();
+                    String content = msg.getContent();
+
+                    System.out.println(sender + ": " + content);
+                }
+
+                else if (obj instanceof FileMessage)
+                {
+                    FileMessage fileMsg = (FileMessage) obj;
+
+                    String sender = fileMsg.getSender();
+                    String fileName = fileMsg.getFilename();
+
+                    System.out.println("File received from " + sender + ": " + fileName);
+                }
+            }
+        }
+        catch (Exception e) {System.out.println("Disconnected from server");}
+    }
+}

src/main/java/com/university/chat/client/TransferProgress.java

@@ -1,4 +1,4 @@
-package com.university.chat.Client;
+package com.university.chat.client;
 
 public class TransferProgress {
 

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

@@ -0,0 +1,123 @@
+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.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Scanner;
+
+public class chatClient
+{
+    public static void main(String[] args)
+    {
+        try
+        {
+            Socket socket = new Socket("localhost", 12345);
+
+            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();
+
+            ChatMessage loginMsg = new ChatMessage(MessageType.LOGIN, username, null, null);
+            out.writeObject(loginMsg);
+            out.flush();
+
+            new Thread(new ServerListener(in)).start();
+
+            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> <message>");
+                            continue;
+                        }
+
+                        String target = parts[1];
+                        String text = parts[2];
+
+                        ChatMessage msg = new ChatMessage(
+                                MessageType.PRIVATE_MESSAGE,
+                                username,
+                                target,
+                                text
+                        );
+
+                        out.writeObject(msg);
+                        out.flush();
+                    }
+
+                    else if (line.equals("/users"))
+                    {
+                        ChatMessage msg = new ChatMessage(
+                                MessageType.USER_LIST,
+                                username,
+                                null,
+                                null
+                        );
+
+                        out.writeObject(msg);
+                        out.flush();
+                    }
+
+                    else if (line.startsWith("/sendfile "))
+                    {
+                        String[] parts = line.split(" ", 3);
+                        if (parts.length < 3)
+                        {
+                            System.out.println("Usage: /sendfile <user> <filepath>");
+                            continue;
+                        }
+
+                        String target = parts[1];
+                        String path = parts[2];
+
+                        byte[] fileData = Files.readAllBytes(Paths.get(path));
+                        String fileName = Paths.get(path).getFileName().toString();
+
+                        FileMessage fileMsg = new FileMessage(
+                                username,
+                                target,
+                                fileName,
+                                fileData
+                        );
+
+                        out.writeObject(fileMsg);
+                        out.flush();
+
+                        System.out.println("File sent: " + fileName);
+                    }
+
+                    else
+                    {
+                        ChatMessage msg = new ChatMessage(
+                                MessageType.PUBLIC_MESSAGE,
+                                username,
+                                null,
+                                line
+                        );
+
+                        out.writeObject(msg);
+                        out.flush();
+                    }
+
+                }
+                catch (Exception e) {System.out.println("command failed: " + e.getMessage());}
+            }
+
+        }
+        catch (Exception e) {System.out.println("Connection failed: " + e.getMessage());}
+    }
+}

src/main/java/com/university/chat/common/ChatMessage.java

@@ -1,4 +1,4 @@
-package com.university.chat.Common;
+package com.university.chat.common;
 
 import java.io.Serializable;
 

src/main/java/com/university/chat/common/FileMessage.java

@@ -1,4 +1,4 @@
-package com.university.chat.Common;
+package com.university.chat.common;
 
 import java.io.Serializable;
 

src/main/java/com/university/chat/common/MessageType.java

@@ -1,4 +1,4 @@
-package com.university.chat.Common;
+package com.university.chat.common;
 
 import java.io.Serializable;
 

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

@@ -0,0 +1,30 @@
+package com.university.chat.server;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class ChatServer
+{
+    public static final UserManager userManager = new UserManager();
+
+    public static void main(String[] args)
+    {
+        int port = 12345;
+
+        try
+        {
+            ServerSocket serverSocket = new ServerSocket(port);
+            System.out.println("Server started on port " + port);
+
+            while (true)
+            {
+                Socket clientSocket = serverSocket.accept();
+                System.out.println("New client connected");
+
+                ClientSession session = new ClientSession(clientSocket, userManager);
+                new Thread(session).start();
+            }
+
+        }
+        catch (Exception e) {e.printStackTrace();}
+    }
+}

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

@@ -0,0 +1,134 @@
+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.*;
+import java.net.Socket;
+import java.nio.file.Files;
+
+public class ClientSession implements Runnable
+{
+    private Socket socket;
+    private ObjectInputStream in;
+    private ObjectOutputStream out;
+
+    private String username;
+    private UserManager userManager;
+
+    public ClientSession(Socket socket, UserManager userManager)
+    {
+        try
+        {
+            this.socket = socket;
+            this.userManager = userManager;
+
+            this.out = new ObjectOutputStream(socket.getOutputStream());
+            this.out.flush();
+            this.in = new ObjectInputStream(socket.getInputStream());
+
+        }
+        catch (IOException e) {System.out.println("Stream error: " + e.getMessage());}
+    }
+
+    public void send(Object obj) throws IOException
+    {
+        out.writeObject(obj);
+        out.flush();
+    }
+
+    @Override
+    public void run()
+    {
+        try
+        {
+            ChatMessage loginMsg = (ChatMessage) in.readObject();
+
+            if (loginMsg.getType() != MessageType.LOGIN)
+            {
+                socket.close();
+                return;
+            }
+
+            this.username = loginMsg.getSender();
+
+            boolean ok = userManager.addUser(username, this);
+
+            if (!ok)
+            {
+                send(new ChatMessage(
+                        MessageType.LOGIN_FAILED,
+                        "SERVER",
+                        username,
+                        "Username already taken"
+                ));
+                socket.close();
+                return;
+            }
+
+            FileManager.createUserFolders(username);
+
+            send(new ChatMessage(
+                    MessageType.LOGIN_SUCCESS,
+                    "SERVER",
+                    username,
+                    "Welcome " + username
+            ));
+
+            while (true)
+            {
+                Object obj = in.readObject();
+
+                if (obj instanceof ChatMessage msg) {handleChat(msg);}
+
+                else if (obj instanceof FileMessage fileMsg) {handleFile(fileMsg);}
+            }
+
+        }
+        catch (Exception e) {System.out.println("Disconnected: " + username);}
+        finally
+        {
+            if (username != null) {userManager.removeUser(username);}
+            try { socket.close(); }
+            catch (Exception ignored) {}
+        }
+    }
+
+    private void handleChat(ChatMessage msg) throws IOException
+    {
+        switch (msg.getType())
+        {
+            case PUBLIC_MESSAGE ->
+            {
+                for (ClientSession session : userManager.getAllSessions()) {session.send(msg);}
+            }
+
+            case PRIVATE_MESSAGE ->
+            {
+                ClientSession target = userManager.getUser(msg.getReceiver());
+                if (target != null) {target.send(msg);}
+            }
+
+            case USER_LIST ->
+            {
+                send(new ChatMessage(
+                        MessageType.USER_LIST,
+                        "SERVER",
+                        username,
+                        userManager.listUsers()
+                ));
+            }
+        }
+    }
+
+    private void handleFile(FileMessage fileMsg) throws IOException
+    {
+        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());
+
+        ClientSession target = userManager.getUser(fileMsg.getReceiver());
+        if (target != null) {target.send(fileMsg);}
+    }
+}

src/main/java/com/university/chat/server/FileManager.java

@@ -1,4 +1,4 @@
-package com.university.chat.Server;
+package com.university.chat.server;
 
 import java.io.IOException;
 import java.nio.file.Files;

src/main/java/com/university/chat/server/UserManager.java

@@ -1,4 +1,4 @@
-package com.university.chat.Server;
+package com.university.chat.server;
 
 import java.util.concurrent.ConcurrentHashMap;