added basic GDX project to this project

core/src/netwerkprog/game/server/Server.java

@@ -0,0 +1,89 @@
+package netwerkprog.game.server;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.HashMap;
+
+public class Server {
+    private ServerSocket serverSocket;
+    private static final int PORT = 8000;
+    private ArrayList<ServerClient> clients = new ArrayList<>();
+    private HashMap<String, Thread> clientThreads = new HashMap<>();
+
+    public static void main(String[] args) {
+        Server server = new Server();
+        server.connect();
+    }
+
+    public void connect() {
+        try {
+            this.serverSocket = new ServerSocket(PORT);
+            boolean running = true;
+            while (running) {
+                System.out.println("[SERVER] listening on port " + PORT);
+                Socket socket = serverSocket.accept();
+
+                System.out.println("[SERVER] got new client on " + socket.getInetAddress().getHostAddress());
+                DataOutputStream outputStream = new DataOutputStream(socket.getOutputStream());
+                DataInputStream inputStream = new DataInputStream(socket.getInputStream());
+
+                outputStream.writeUTF("Enter nickname: ");
+                String nickname = inputStream.readUTF();
+
+                System.out.println("[SERVER] got nickname " + nickname);
+                ServerClient serverClient = new ServerClient(nickname, socket,this);
+
+                Thread t = new Thread(serverClient);
+                t.start();
+
+                clientThreads.put(nickname,t);
+                this.clients.add(serverClient);
+
+                sendMessage(nickname, "--- Welcome! ---\nPeople online : " + clients.size());
+
+                clients.forEach(yeet -> sendToEveryoneExcept(nickname,nickname + " joined the server! [" + socket.getInetAddress().getHostAddress() + "]"));
+            }
+
+            this.serverSocket.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void sendToEveryone(String text) {
+        for (ServerClient serverClient : clients) {
+            serverClient.writeUTF(text);
+        }
+    }
+
+    public void sendToEveryoneExcept(String name, String text) {
+        for (ServerClient serverClient : clients) {
+            if (!serverClient.getName().equals(name))
+                serverClient.writeUTF(text);
+        }
+    }
+
+    public void sendMessage(String name, String text) {
+        for (ServerClient serverClient : clients) {
+            if (serverClient.getName().equals(name)) {
+                serverClient.writeUTF(text);
+                break;
+            }
+        }
+    }
+
+    public void removeClient(ServerClient serverClient) {
+        this.clients.remove(serverClient);
+        try {
+            this.clientThreads.get(serverClient.getName()).join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        this.clientThreads.remove(serverClient.getName());
+        this.sendToEveryone(serverClient.getName() + " left!");
+    }
+}

core/src/netwerkprog/game/server/ServerClient.java

@@ -0,0 +1,69 @@
+package netwerkprog.game.server;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.Socket;
+
+public class ServerClient implements Runnable {
+    private DataInputStream in;
+    private DataOutputStream out;
+    private Socket socket;
+    private String name;
+    private Server server;
+    private boolean isConnected = false;
+
+    public ServerClient(String name, Socket socket, Server server) {
+        this.name = name;
+        this.server = server;
+        this.socket = socket;
+        try {
+            this.in = new DataInputStream(socket.getInputStream());
+            this.out = new DataOutputStream(socket.getOutputStream());
+            this.isConnected = true;
+        } catch (IOException e) {
+            this.isConnected = false;
+            e.printStackTrace();
+        }
+    }
+
+    public void readUTF() {
+        try {
+            System.out.println("[SERVERCLIENT] got message: " + in.readUTF());
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void writeUTF(String text) {
+        try {
+            this.out.writeUTF(text);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void run() {
+        while (isConnected) {
+            try {
+                String received = this.in.readUTF();
+                if (received.equals("\\quit")) {
+                    isConnected = false;
+                    this.server.removeClient(this);
+                } else {
+                    this.server.sendToEveryoneExcept(this.name,"<" + this.name + "> : " + received);
+                }
+            } catch (IOException e) {
+                System.out.println("[SERVERCLIENT] caught exception - " + e.getMessage());
+                System.out.println("[SERVERCLIENT] terminating failing connection...");
+                isConnected = false;
+                System.out.println("[SERVERCLIENT] done!");
+            }
+        }
+    }
+
+    public String getName() {
+        return name;
+    }
+}