complete server-side classes

This commit is contained in:
2026-06-13 22:38:26 +03:30
parent 240eac0504
commit e7fa0c9d2c
2 changed files with 143 additions and 17 deletions
@@ -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();
}
}
}
@@ -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();
}
}
}