edited the 'networkDialog' and added 'battleShipLocalServer' and 'ReceivedMessage' and 'README'

edited the networkDialog so the client can decide, whether he want, to connect to a derver or create and host a new one, added the 'BattleshipLocalServer', the class responcible for creating a new server and added 'Receivedmessage'
and added a README for the Background-music licence

Projekte/battleship/client/src/main/java/pp/battleship/client/ClientServer.java

@@ -1,7 +0,0 @@
-package pp.battleship.client;
-
-/**
- *this class is used for the server, when one player decides to host the server locally
- */
-public class ClientServer {
-}

Projekte/battleship/client/src/main/java/pp/battleship/client/GameSound.java

@@ -30,7 +30,6 @@ public class GameSound extends AbstractAppState implements GameEventListener {
     private static final Logger LOGGER = System.getLogger(GameSound.class.getName());
     private static final Preferences PREFERENCES = getPreferences(GameSound.class);
     private static final String ENABLED_PREF = "enabled"; //NON-NLS
-
     private AudioNode splashSound;
     private AudioNode shipDestroyedSound;
     private AudioNode explosionSound;

Projekte/battleship/client/src/main/java/pp/battleship/client/NetworkDialog.java

@@ -7,10 +7,13 @@
 
 package pp.battleship.client;
 
+import com.simsilica.lemur.Checkbox;
 import com.simsilica.lemur.Container;
 import com.simsilica.lemur.Label;
 import com.simsilica.lemur.TextField;
 import com.simsilica.lemur.component.SpringGridLayout;
+import pp.battleship.client.server.BattleshipLocalServer;
+import pp.battleship.client.server.BattleshipLocalServer;
 import pp.dialog.Dialog;
 import pp.dialog.DialogBuilder;
 import pp.dialog.SimpleDialog;
@@ -37,6 +40,7 @@ class NetworkDialog extends SimpleDialog {
     private int portNumber;
     private Future<Object> connectionFuture;
     private Dialog progressDialog;
+    private boolean localServer = false;
 
     /**
      * Constructs a new NetworkDialog.
@@ -57,6 +61,13 @@ class NetworkDialog extends SimpleDialog {
         input.addChild(new Label(lookup("port.number") + ":  "));
         input.addChild(port, 1);
 
+        /*
+         * this checkbox controls, whether it will connect to an existing server or create a separate server
+         */
+        Checkbox localServerCb = new Checkbox(lookup("local.server"));
+        localServerCb.setChecked(false);
+        localServerCb.addClickCommands(s -> localServer = !localServer);
+
         DialogBuilder.simple(app.getDialogManager())
                      .setTitle(lookup("server.dialog"))
                      .setExtension(d -> d.addChild(input))
@@ -65,13 +76,14 @@ class NetworkDialog extends SimpleDialog {
                      .setOkClose(false)
                      .setNoClose(false)
                      .build(this);
+        addChild(localServerCb); // adds the checkbox to the network dialog at the bottom
     }
 
     /**
      * Handles the action for the connect button in the connection dialog.
      * Tries to parse the port number and initiate connection to the server.
      */
-    private void connect() {
+    private void connectServer() {
         LOGGER.log(Level.INFO, "connect to host={0}, port={1}", host, port); //NON-NLS
         try {
             hostname = host.getText().trim().isEmpty() ? LOCALHOST : host.getText();
@@ -84,6 +96,40 @@ private void connect() {
         }
     }
 
+    /**
+     * connects to the server, creates one, if no server is up
+     */
+    public void connect() {
+        if (localServer) {
+            startLocalServer(); //starts a local server
+            try {
+                Thread.sleep(1000); // waits, to ensure, that the server in the separate Thread has enough time to start properly
+            }
+            catch (Exception e) {
+                LOGGER.log(Level.WARNING, e.getMessage(), e);
+            }
+            connectServer(); // connects to the server, that was just created
+        }
+        else {
+            connectServer(); // connects to existing server, when the server si not running, or not started by one of the clients
+        }
+    }
+
+    /**
+     *starts a local server, in another thread
+     */
+    private void startLocalServer() {
+        new Thread(() -> { //creates new Thread
+            try {
+                BattleshipLocalServer battleshipLocalServer = new BattleshipLocalServer(Integer.parseInt(port.getText())); // creates local server, with the given port numbers
+                battleshipLocalServer.run(); // runs the local server
+            }
+            catch (Exception e) {
+                LOGGER.log(Level.ERROR, e.getMessage(), e);
+            }
+        }).start(); // starts the thread
+    }
+
     /**
      * Creates a dialog indicating that the connection is in progress.
      */

Projekte/battleship/client/src/main/java/pp/battleship/client/server/BattleshipLocalServer.java

@@ -0,0 +1,178 @@
+////////////////////////////////////////
+// Programming project code
+// UniBw M, 2022, 2023, 2024
+// www.unibw.de/inf2
+// (c) Mark Minas (mark.minas@unibw.de)
+////////////////////////////////////////
+
+package pp.battleship.client.server;
+
+import com.jme3.network.ConnectionListener;
+import com.jme3.network.HostedConnection;
+import com.jme3.network.Message;
+import com.jme3.network.MessageListener;
+import com.jme3.network.Network;
+import com.jme3.network.Server;
+import com.jme3.network.serializing.Serializer;
+import pp.battleship.BattleshipConfig;
+import pp.battleship.game.server.Player;
+import pp.battleship.game.server.ServerGameLogic;
+import pp.battleship.game.server.ServerSender;
+import pp.battleship.message.client.ClientMessage;
+import pp.battleship.message.client.MapMessage;
+import pp.battleship.message.client.ShootMessage;
+import pp.battleship.message.server.EffectMessage;
+import pp.battleship.message.server.GameDetails;
+import pp.battleship.message.server.ServerMessage;
+import pp.battleship.message.server.StartBattleMessage;
+import pp.battleship.model.Battleship;
+import pp.battleship.model.IntPoint;
+import pp.battleship.model.Shot;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.lang.System.Logger;
+import java.lang.System.Logger.Level;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.logging.LogManager;
+
+/**
+ * Server implementing the visitor pattern as MessageReceiver for ClientMessages
+ */
+public class BattleshipLocalServer implements MessageListener<HostedConnection>, ConnectionListener, ServerSender {
+    private static final Logger LOGGER = System.getLogger(BattleshipLocalServer.class.getName());
+    private static final File CONFIG_FILE = new File("server.properties");
+    private final BattleshipConfig config = new BattleshipConfig();
+    private Server myServer;
+    private static int PORT_NUMBER;
+    private final ServerGameLogic logic;
+    private final BlockingQueue<ReceivedMessage> pendingMessages = new LinkedBlockingQueue<>();
+
+    static {
+        // Configure logging
+        LogManager manager = LogManager.getLogManager();
+        try {
+            manager.readConfiguration(new FileInputStream("logging.properties"));
+            LOGGER.log(Level.INFO, "Successfully read logging properties"); //NON-NLS
+        }
+        catch (IOException e) {
+            LOGGER.log(Level.INFO, e.getMessage());
+        }
+    }
+
+    /**
+     * this constructs the local battleship server
+     *
+     * @param portNumber the port number, the local-host should be accessed at
+     */
+    public BattleshipLocalServer(int portNumber) {
+        config.readFromIfExists(CONFIG_FILE);
+        PORT_NUMBER = portNumber;
+        LOGGER.log(Level.INFO, "Configuration: {0}", config); //NON-NLS
+        logic = new ServerGameLogic(this, config);
+    }
+
+    public void run() {
+        startServer();
+        while (true)
+            processNextMessage();
+    }
+
+    /**
+     * this method is used to start a server
+     */
+    private void startServer() {
+        try {
+            LOGGER.log(Level.INFO, "Starting server..."); //NON-NLS
+            myServer = Network.createServer(PORT_NUMBER); // creates new server, with the port given before
+            initializeSerializables();
+            myServer.start();
+            registerListeners();
+            LOGGER.log(Level.INFO, "Server started: {0}", myServer.isRunning()); //NON-NLS
+        }
+        catch (IOException e) {
+            LOGGER.log(Level.ERROR, "Couldn't start server: {0}", e.getMessage()); //NON-NLS
+            exit(1);
+        }
+    }
+
+    private void processNextMessage() {
+        try {
+            pendingMessages.take().process(logic);
+        }
+        catch (InterruptedException ex) {
+            LOGGER.log(Level.INFO, "Interrupted while waiting for messages"); //NON-NLS
+            Thread.currentThread().interrupt();
+        }
+    }
+
+    private void initializeSerializables() {
+        Serializer.registerClass(GameDetails.class);
+        Serializer.registerClass(StartBattleMessage.class);
+        Serializer.registerClass(MapMessage.class);
+        Serializer.registerClass(ShootMessage.class);
+        Serializer.registerClass(EffectMessage.class);
+        Serializer.registerClass(Battleship.class);
+        Serializer.registerClass(IntPoint.class);
+        Serializer.registerClass(Shot.class);
+    }
+
+    private void registerListeners() {
+        myServer.addMessageListener(this, MapMessage.class);
+        myServer.addMessageListener(this, ShootMessage.class);
+        myServer.addConnectionListener(this);
+    }
+
+    @Override
+    public void messageReceived(HostedConnection source, Message message) {
+        LOGGER.log(Level.INFO, "message received from {0}: {1}", source.getId(), message); //NON-NLS
+        if (message instanceof ClientMessage clientMessage)
+            pendingMessages.add(new ReceivedMessage(clientMessage, source.getId()));
+    }
+
+    @Override
+    public void connectionAdded(Server server, HostedConnection hostedConnection) {
+        LOGGER.log(Level.INFO, "new connection {0}", hostedConnection); //NON-NLS
+        logic.addPlayer(hostedConnection.getId());
+    }
+
+    @Override
+    public void connectionRemoved(Server server, HostedConnection hostedConnection) {
+        LOGGER.log(Level.INFO, "connection closed: {0}", hostedConnection); //NON-NLS
+        final Player player = logic.getPlayerById(hostedConnection.getId());
+        if (player == null)
+            LOGGER.log(Level.INFO, "closed connection does not belong to an active player"); //NON-NLS
+        else { //NON-NLS
+            LOGGER.log(Level.INFO, "closed connection belongs to {0}", player); //NON-NLS
+            exit(0);
+        }
+    }
+
+    private void exit(int exitValue) { //NON-NLS
+        LOGGER.log(Level.INFO, "close request"); //NON-NLS
+        if (myServer != null)
+            for (HostedConnection client : myServer.getConnections()) //NON-NLS
+                if (client != null) client.close("Game over"); //NON-NLS
+        System.exit(exitValue);
+    }
+
+    /**
+     * Send the specified message to the specified connection.
+     *
+     * @param id      the connection id
+     * @param message the message
+     */
+    public void send(int id, ServerMessage message) {
+        if (myServer == null || !myServer.isRunning()) {
+            LOGGER.log(Level.ERROR, "no server running when trying to send {0}", message); //NON-NLS
+            return;
+        }
+        final HostedConnection connection = myServer.getConnection(id);
+        if (connection != null)
+            connection.send(message);
+        else
+            LOGGER.log(Level.ERROR, "there is no connection with id={0}", id); //NON-NLS
+    }
+}

Projekte/battleship/client/src/main/java/pp/battleship/client/server/ReceivedMessage.java

@@ -0,0 +1,17 @@
+////////////////////////////////////////
+// Programming project code
+// UniBw M, 2022, 2023, 2024
+// www.unibw.de/inf2
+// (c) Mark Minas (mark.minas@unibw.de)
+////////////////////////////////////////
+
+package pp.battleship.client.server;
+
+import pp.battleship.message.client.ClientInterpreter;
+import pp.battleship.message.client.ClientMessage;
+
+record ReceivedMessage(ClientMessage message, int from) {
+    void process(ClientInterpreter interpreter) {
+        message.accept(interpreter, from);
+    }
+}

Projekte/battleship/client/src/main/resources/Sound/Background/README.txt

@@ -0,0 +1,3 @@
+The soundtrack for the background-music is from:
+https://pixabay.com/music/future-bass-nightfall-future-bass-music-228100/
+the soundtrack is free to use

Projekte/battleship/model/src/main/resources/battleship.properties

@@ -40,3 +40,4 @@ map.doesnt.fit=The map doesn't fit to this game
 background.music.checkbox= Background music on/off
 background.music.volume= Background volume
 player.submitted.invalid.map= invalid map submitted
+local.server= instantiate local server

Projekte/battleship/model/src/main/resources/battleship_de.properties

@@ -40,4 +40,5 @@ map.doesnt.fit=Diese Karte passt nicht zu diesem Spiel
 background.music.checkbox= Musik an/aus
 background.music.volume= Musiklautstärke
 player.submitted.invalid.map= Invalide karte gegeben
+local.server=Lokalen Server erstellen