diff --git a/src/main/java/com/university/chat/Server/ChatServer.java b/src/main/java/com/university/chat/Server/ChatServer.java index b2a35ae..87fc954 100644 --- a/src/main/java/com/university/chat/Server/ChatServer.java +++ b/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) - // This MUST be shared by all ClientSession threads so that - // broadcasting and private messaging work correctly. + + 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. + final int port = 12345; + System.out.println("chat server starting on port "+port); + try (ServerSocket serverSocket = new ServerSocket(port)) { + System.out.println("server is listening..."); + + while (true) + { + Socket clientSocket = serverSocket.accept(); + System.out.println("new client connected from "+clientSocket.getInetAddress()); + + ClientSession session = new ClientSession(clientSocket, userManager); + Thread clientThread = new Thread(session); + clientThread.start(); + } + } catch (IOException e) + { + System.err.println(e.getMessage()); + e.printStackTrace(); + } + } } diff --git a/src/main/java/com/university/chat/Server/ClientSession.java b/src/main/java/com/university/chat/Server/ClientSession.java index f09d64a..7dcd54c 100644 --- a/src/main/java/com/university/chat/Server/ClientSession.java +++ b/src/main/java/com/university/chat/Server/ClientSession.java @@ -2,44 +2,118 @@ 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 ObjectInputStream in; + private ObjectOutputStream out; + 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 + { + out = new ObjectOutputStream(socket.getOutputStream()); + out.flush(); + in = new ObjectInputStream(socket.getInputStream()); + } catch (IOException e) + { + e.printStackTrace(); + } } @Override public void run() { try { - - // TODO: Welcome the user (login step) + // Welcome the user (login step) // 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)) + { + socket.close(); + return; + } + ChatMessage loginMsg = (ChatMessage) obj; + if (loginMsg.getType() != MessageType.LOGIN) + { + out.writeObject(new ChatMessage(MessageType.LOGIN_FAILED, "Server", null, "Invalid login request")); + out.flush(); + socket.close(); + return; + } + // 3. Extract the username. + String requestedUser = loginMsg.getContent(); + // 4. Try to register the user via userManager.addUser(...). + boolean success = userManager.addUser(requestedUser, this); + // 5. If the username is taken, send back LOGIN_FAILED and close the socket. + if (!success) + { + out.writeObject(new ChatMessage(MessageType.LOGIN_FAILED, "Server", null, "Username is already taken")); + out.flush(); + socket.close(); + return; + } + // 6. Otherwise, create the user's folders with FileManager.createUserFolders(...) // and send back LOGIN_SUCCESS. + this.username = requestedUser; + out.writeObject(new ChatMessage(MessageType.LOGIN_SUCCESS, "Server", null, "Welcome "+username)); + out.flush(); + System.out.println("User logged in: "+username); - // TODO: Main message loop + // 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). + while (true) + { + Object received = in.readObject(); + if (received instanceof ChatMessage) + { + handleChatMessage((ChatMessage) received); + } else if (received instanceof FileMessage) + { + handleFileMessage((FileMessage) received); + } + } } catch (Exception e) { System.out.println("Disconnected: " + username); } finally { - // TODO: Remove the user from UserManager so they no longer + // 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("User removed: "+username); + } + try + { + if (socket != null && !socket.isClosed()) + { + socket.close(); + } + } catch (IOException e) + { + e.printStackTrace(); + } } } @@ -47,13 +121,36 @@ public class ClientSession implements Runnable { private void handleChatMessage(ChatMessage msg) throws IOException { switch (msg.getType()) { case PUBLIC_MESSAGE -> { - // TODO: Broadcast this message to every connected client. + // Broadcast this message to every connected client. + for (ClientSession session : userManager.getAllSessions()) + { + if (session != this) + { + session.out.writeObject(msg); + session.out.flush(); + } + } } case PRIVATE_MESSAGE -> { - // TODO: Forward this message to the receiver user. + // Forward this message to the receiver user. + String receiver = msg.getReceiver(); + ClientSession target = userManager.getUser(receiver); + if (target != null) + { + target.out.writeObject(msg); + target.out.flush(); + } else { + out.writeObject(new ChatMessage(MessageType.PRIVATE_MESSAGE, "Server", null, + "User " + receiver + " is not online.")); + out.flush(); + } } case USER_LIST -> { - // TODO: Reply to the requester with the list of online users. + // Reply to the requester with the list of online users. + String list = userManager.listUsers(); + ChatMessage listMsg = new ChatMessage(MessageType.USER_LIST, "Server", null, list); + out.writeObject(listMsg); + out.flush(); } } } @@ -66,6 +163,16 @@ public class ClientSession implements Runnable { Files.write(sentPath, fileMsg.getData()); Files.write(recvPath, fileMsg.getData()); - // TODO: Forward the received file-message to the destination user. + // Forward the received file-message to the destination user. + ClientSession receiver = userManager.getUser(fileMsg.getReceiver()); + if (receiver != null) + { + receiver.out.writeObject(fileMsg); + receiver.out.flush(); + } else + { + out.writeObject(new ChatMessage(MessageType.PRIVATE_MESSAGE, "Server", null, "Cannot send file; user "+fileMsg.getReceiver()+" is offline")); + out.flush(); + } } } \ No newline at end of file