Reduced opentopo api calls // added 4 char locator new-filter // added new band and tropo filter and priority sorter // decreased map load

Audio did not work, but better debug handling.

.github/workflows/pr-compile-check.yml

@@ -11,18 +11,18 @@ env:
 
 jobs:
   compile:
-    name: Compile (Java 17)
+    name: Compile (Java 21)
     runs-on: ubuntu-latest
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 17
+      - name: Set up Java 21
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "17"
+          java-version: "21"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw

github_docs/de-Installation.md

@@ -116,12 +116,47 @@ Die Datei `de.x08.KST4Contest.flatpakref` aus dem [aktuellen Release](https://gi
 flatpak install de.x08.KST4Contest.flatpakref
 ```
 
-Oder den Remote manuell hinzufügen:
+Oder den Remote manuell hinzufügen (empfohlen für Nightly/Beta-Zugriff):
 ```bash
-flatpak remote-add kst4contest https://praktimarc.github.io/kst4contest/
+flatpak remote-add --if-not-exists kst4contest https://praktimarc.github.io/kst4contest/kst4contest.flatpakrepo
 flatpak install kst4contest de.x08.KST4Contest
 ```
 
+#### Flatpak-Kanäle (nightly / beta / stable)
+
+Das Flatpak-Repository enthält drei Kanäle, die alle im selben Remote liegen:
+
+| Kanal | Inhalt | Wird gebaut bei |
+|---|---|---|
+| `stable` | Aktuelle stabile Version | Jedem normalen Release-Tag |
+| `beta` | Vorab-Version | Tags mit `beta-` Präfix |
+| `nightly` | Entwicklungsstand (main-Branch) | Täglich / jedem Push auf main |
+
+Remote einmalig hinzufügen, dann den gewünschten Kanal installieren:
+
+```bash
+flatpak remote-add --if-not-exists kst4contest https://praktimarc.github.io/kst4contest/kst4contest.flatpakrepo
+
+# Stable (Standard)
+flatpak install kst4contest de.x08.KST4Contest
+
+# Beta
+flatpak install kst4contest de.x08.KST4Contest//beta
+
+# Nightly
+flatpak install kst4contest de.x08.KST4Contest//nightly
+```
+
+> **Hinweis:** Flatpak erlaubt nur eine installierte Version pro App-ID gleichzeitig. Um den Kanal zu wechseln, zuerst die aktuelle Version deinstallieren:
+> ```bash
+> flatpak uninstall de.x08.KST4Contest
+> flatpak install kst4contest de.x08.KST4Contest//nightly
+> ```
+
+Updates erfolgen wie gewohnt mit `flatpak update`.
+
+Die `flatpakref`-Dateien für Beta und Stable liegen jeweils im entsprechenden [GitHub-Release](https://github.com/praktimarc/kst4contest/releases). Das Nightly-`flatpakref` (`de.x08.KST4Contest.nightly.flatpakref`) ist als Artifact im [GitHub Actions](https://github.com/praktimarc/kst4contest/actions)-Tab verfügbar (wird 14 Tage aufbewahrt) – der Remote-Weg oben ist für Nightly daher meist einfacher.
+
 ### macOS
 1. DMG-Datei für die eigene Architektur herunterladen (Apple Silicon oder Intel).
 2. DMG-Datei öffnen.

github_docs/en-Installation.md

@@ -116,12 +116,47 @@ Download `de.x08.KST4Contest.flatpakref` from the [latest release](https://githu
 flatpak install de.x08.KST4Contest.flatpakref
 ```
 
-Or add the remote manually:
+Or add the remote manually (recommended for nightly/beta access):
 ```bash
-flatpak remote-add kst4contest https://praktimarc.github.io/kst4contest/
+flatpak remote-add --if-not-exists kst4contest https://praktimarc.github.io/kst4contest/kst4contest.flatpakrepo
 flatpak install kst4contest de.x08.KST4Contest
 ```
 
+#### Flatpak Channels (nightly / beta / stable)
+
+The Flatpak repository provides three channels, all served from the same remote:
+
+| Channel | Content | Built on |
+|---|---|---|
+| `stable` | Current stable version | Every normal release tag |
+| `beta` | Pre-release version | Tags prefixed with `beta-` |
+| `nightly` | Development build (main branch) | Every push to main / daily |
+
+Add the remote once, then install the channel you want:
+
+```bash
+flatpak remote-add --if-not-exists kst4contest https://praktimarc.github.io/kst4contest/kst4contest.flatpakrepo
+
+# Stable (default)
+flatpak install kst4contest de.x08.KST4Contest
+
+# Beta
+flatpak install kst4contest de.x08.KST4Contest//beta
+
+# Nightly
+flatpak install kst4contest de.x08.KST4Contest//nightly
+```
+
+> **Note:** Flatpak only allows one installed version per App-ID at a time. To switch channels, uninstall the current version first:
+> ```bash
+> flatpak uninstall de.x08.KST4Contest
+> flatpak install kst4contest de.x08.KST4Contest//nightly
+> ```
+
+Updates work as usual with `flatpak update`.
+
+The `flatpakref` files for beta and stable are attached to their respective [GitHub Releases](https://github.com/praktimarc/kst4contest/releases). The nightly `flatpakref` (`de.x08.KST4Contest.nightly.flatpakref`) is available as an artifact on the [GitHub Actions](https://github.com/praktimarc/kst4contest/actions) tab (kept for 14 days) — for nightly builds, the manual remote approach above is usually more convenient.
+
 ### macOS
 1. Download the DMG file for your architecture (Apple Silicon or Intel).
 2. Open the DMG file.

pom.xml

@@ -24,12 +24,12 @@
         <launcher>${project.artifactId}</launcher>
         <appName>${project.artifactId}</appName>
         <main.class>kst4contest.view.Kst4ContestApplication</main.class>
-        <java.version>17</java.version>
+        <java.version>21</java.version>
         <required.maven.version>3.6.3</required.maven.version>
         <jar.filename>${project.artifactId}-${project.version}</jar.filename>
 
         <!-- Dependency versions -->
-        <javafx.version>19.0.2.1</javafx.version>
+        <javafx.version>21.0.5</javafx.version>
         <jetbrains.annotations.version>24.0.1</jetbrains.annotations.version>
         <junit.version>5.10.1</junit.version>
         <lombok.version>1.18.44</lombok.version>
@@ -50,8 +50,8 @@
         <maven.wrapper.plugin>3.2.0</maven.wrapper.plugin>
         <moditect.maven.plugin>1.0.0.RC2</moditect.maven.plugin>
         <jpackage.maven.plugin>0.1.3</jpackage.maven.plugin>
-        <maven.pmd.version>3.21.2</maven.pmd.version>
+        <maven.pmd.version>3.28.0</maven.pmd.version>
-        <pmd.version>6.55.0</pmd.version>
+        <pmd.version>7.17.0</pmd.version>
         <codehaus.version.plugin>2.16.1</codehaus.version.plugin>
         <javafx.maven.plugin>0.0.8</javafx.maven.plugin>
         <spotbugs.maven.plugin>4.9.8.2</spotbugs.maven.plugin>
@@ -93,6 +93,13 @@
             <version>${javafx.version}</version>
         </dependency>
 
+        <!-- JLayer: pure-Java MP3 decoder, used instead of JavaFX Media for Flatpak audio compatibility -->
+        <dependency>
+            <groupId>javazoom</groupId>
+            <artifactId>jlayer</artifactId>
+            <version>1.0.1</version>
+        </dependency>
+
         <!-- SQLite -->
         <dependency>
             <groupId>org.xerial</groupId>
@@ -280,30 +287,7 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-pmd-plugin</artifactId>
                 <version>${maven.pmd.version}</version>
-                <dependencies>
-                    <dependency>
-                        <groupId>net.sourceforge.pmd</groupId>
-                        <artifactId>pmd-core</artifactId>
-                        <version>${pmd.version}</version>
-                    </dependency>
-                    <dependency>
-                        <groupId>net.sourceforge.pmd</groupId>
-                        <artifactId>pmd-java</artifactId>
-                        <version>${pmd.version}</version>
-                    </dependency>
-                    <dependency>
-                        <groupId>net.sourceforge.pmd</groupId>
-                        <artifactId>pmd-javascript</artifactId>
-                        <version>${pmd.version}</version>
-                    </dependency>
-                    <dependency>
-                        <groupId>net.sourceforge.pmd</groupId>
-                        <artifactId>pmd-jsp</artifactId>
-                        <version>${pmd.version}</version>
-                    </dependency>
-                </dependencies>
                 <configuration>
-                    <sourceEncoding>${project.build.sourceEncoding}</sourceEncoding>
                     <minimumTokens>100</minimumTokens>
                     <targetJdk>${java.version}</targetJdk>
                     <linkXRef>false</linkXRef>
@@ -436,6 +420,7 @@
                                 <addmodule>javafx.graphics</addmodule>
                                 <addmodule>javafx.fxml</addmodule>
                                 <addmodule>javafx.web</addmodule>
+                                <addmodule>javafx.media</addmodule>
                                 <addmodule>java.sql</addmodule>
                                 <addmodule>java.net.http</addmodule>
                                 <addmodule>jdk.crypto.ec</addmodule>

src/main/java/kst4contest/utils/PlayAudioUtils.java

@@ -1,13 +1,18 @@
 package kst4contest.utils;
 
-import javafx.scene.media.Media;
+import javazoom.jl.decoder.JavaLayerException;
-import javafx.scene.media.MediaPlayer;
+import javazoom.jl.player.Player;
 import kst4contest.ApplicationConstants;
 
-import java.io.File;
+import java.io.BufferedInputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
 import java.util.Arrays;
-import java.util.LinkedList;
 import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * This part of the client drives the sounds. Its a singleton instance. All audio outs are directed to this instance.<br>
@@ -113,8 +118,16 @@ public class PlayAudioUtils {
 
     }
 
-    private Queue<Media> musicList = new LinkedList<Media>();
+    private final Queue<String> musicList = new ConcurrentLinkedQueue<>();
-    private MediaPlayer mediaPlayer ;
+    /** True once audio fails; prevents repeated error logs and further play attempts. */
+    private final AtomicBoolean audioUnavailable = new AtomicBoolean(false);
+    /** True while the drain loop is running; prevents duplicate concurrent drains. */
+    private final AtomicBoolean playing = new AtomicBoolean(false);
+    private final ExecutorService audioThread = Executors.newSingleThreadExecutor(r -> {
+        Thread t = new Thread(r, "audio-player");
+        t.setDaemon(true);
+        return t;
+    });
 
     /**
      * Plays notification sounds out of the windws 95 box by given action character<br/>
@@ -131,40 +144,31 @@ public class PlayAudioUtils {
      */
     public void playNoiseLauncher(char actionChar) {
 
-
-
-//        ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISESTARTUP.mp3");
-
-
         switch (actionChar){
             case '-':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/tick.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/tick.mp3"));
                 break;
             case '!':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISESTARTUP.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISESTARTUP.mp3"));
                 break;
             case 'C':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISECQWINDOW.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISECQWINDOW.mp3"));
                 break;
             case 'P':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISEPMWINDOW.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISEPMWINDOW.mp3"));
                 break;
             case 'E':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISEERROR.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISEERROR.mp3"));
                 break;
             case 'N':
-                    musicList.add(new Media(new File (ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISENOTIFY.mp3")).toURI().toString()));
+                musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/NOISENOTIFY.mp3"));
                 break;
-//                case 'M':
-//                    musicList.add(new Media(new File ("VOICE.mp3").toURI().toString()));
-//                    break;
 
             default:
                 System.out.println("[KST4ContestApp, warning, letter not defined!]");
 
         }
         playMusic();
-//		mediaPlayer.dispose();
 
     }
 
@@ -183,125 +187,124 @@ public class PlayAudioUtils {
         for (char letterToPlay: playThisInCW){
             switch (letterToPlay){
                 case 'A':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRA.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRA.mp3"));
                     break;
                 case 'B':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRB.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRB.mp3"));
                     break;
                 case 'C':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRC.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRC.mp3"));
                     break;
                 case 'D':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRD.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRD.mp3"));
                     break;
                 case 'E':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRE.mp3"));
                     break;
                 case 'F':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRF.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRF.mp3"));
                     break;
                 case 'G':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRG.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRG.mp3"));
                     break;
                 case 'H':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRH.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRH.mp3"));
                     break;
                 case 'I':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRI.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRI.mp3"));
                     break;
                 case 'J':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRJ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRJ.mp3"));
                     break;
                 case 'K':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRK.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRK.mp3"));
                     break;
                 case 'L':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRL.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRL.mp3"));
                     break;
                 case 'M':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRM.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRM.mp3"));
                     break;
                 case 'N':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRN.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRN.mp3"));
                     break;
                 case 'O':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRO.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRO.mp3"));
                     break;
                 case 'P':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRP.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRP.mp3"));
                     break;
                 case 'Q':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRQ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRQ.mp3"));
                     break;
                 case 'R':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRR.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRR.mp3"));
                     break;
                 case 'S':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRS.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRS.mp3"));
                     break;
                 case 'T':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRT.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRT.mp3"));
                     break;
                 case 'U':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRU.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRU.mp3"));
                     break;
                 case 'V':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRV.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRV.mp3"));
                     break;
                 case 'W':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRW.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRW.mp3"));
                     break;
                 case 'X':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRX.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRX.mp3"));
                     break;
                 case 'Y':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRY.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRY.mp3"));
                     break;
                 case 'Z':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRZ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRZ.mp3"));
                     break;
                 case '1':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR1.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR1.mp3"));
                     break;
                 case '2':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR2.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR2.mp3"));
                     break;
                 case '3':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR3.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR3.mp3"));
                     break;
                 case '4':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR4.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR4.mp3"));
                     break;
                 case '5':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR5.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR5.mp3"));
                     break;
                 case '6':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR6.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR6.mp3"));
                     break;
                 case '7':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR7.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR7.mp3"));
                     break;
                 case '8':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR8.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR8.mp3"));
                     break;
                 case '9':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR9.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR9.mp3"));
                     break;
                 case '0':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR0.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTR0.mp3"));
                     break;
                 case '/':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRSTROKE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRSTROKE.mp3"));
                     break;
                 case ' ':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRSPACE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/LTTRSPACE.mp3"));
                     break;
                 default:
                     System.out.println("[KST4ContestApp, warning, letter not defined:] cwLetters = " + Arrays.toString(playThisInCW));
             }
         }
         playMusic();
-//		mediaPlayer.dispose();
 
     }
 
@@ -323,162 +326,166 @@ public class PlayAudioUtils {
         for (char letterToPlay: spellThisWithVoice){
             switch (letterToPlay){
                 case '!':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEBELL.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEBELL.mp3"));
                     break;
                 case '?':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEYOUGOTMAIL.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEYOUGOTMAIL.mp3"));
                     break;
                 case '#':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEHELLO.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEHELLO.mp3"));
                     break;
                 case '*':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE73.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE73.mp3"));
                     break;
                 case '$':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICESTROKEPORTABLE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICESTROKEPORTABLE.mp3"));
                     break;
                 case 'A':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEA.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEA.mp3"));
                     break;
                 case 'B':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEB.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEB.mp3"));
                     break;
                 case 'C':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEC.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEC.mp3"));
                     break;
                 case 'D':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICED.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICED.mp3"));
                     break;
                 case 'E':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEE.mp3"));
                     break;
                 case 'F':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEF.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEF.mp3"));
                     break;
                 case 'G':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEG.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEG.mp3"));
                     break;
                 case 'H':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEH.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEH.mp3"));
                     break;
                 case 'I':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEI.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEI.mp3"));
                     break;
                 case 'J':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEJ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEJ.mp3"));
                     break;
                 case 'K':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEK.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEK.mp3"));
                     break;
                 case 'L':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEL.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEL.mp3"));
                     break;
                 case 'M':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEM.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEM.mp3"));
                     break;
                 case 'N':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEN.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEN.mp3"));
                     break;
                 case 'O':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEO.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEO.mp3"));
                     break;
                 case 'P':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEP.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEP.mp3"));
                     break;
                 case 'Q':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEQ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEQ.mp3"));
                     break;
                 case 'R':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICER.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICER.mp3"));
                     break;
                 case 'S':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICES.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICES.mp3"));
                     break;
                 case 'T':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICET.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICET.mp3"));
                     break;
                 case 'U':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEU.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEU.mp3"));
                     break;
                 case 'V':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEV.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEV.mp3"));
                     break;
                 case 'W':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEW.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEW.mp3"));
                     break;
                 case 'X':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEX.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEX.mp3"));
                     break;
                 case 'Y':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEY.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEY.mp3"));
                     break;
                 case 'Z':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEZ.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICEZ.mp3"));
                     break;
                 case '1':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE1.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE1.mp3"));
                     break;
                 case '2':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE2.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE2.mp3"));
                     break;
                 case '3':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE3.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE3.mp3"));
                     break;
                 case '4':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE4.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE4.mp3"));
                     break;
                 case '5':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE5.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE5.mp3"));
                     break;
                 case '6':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE6.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE6.mp3"));
                     break;
                 case '7':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE7.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE7.mp3"));
                     break;
                 case '8':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE8.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE8.mp3"));
                     break;
                 case '9':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE9.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE9.mp3"));
                     break;
                 case '0':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE0.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICE0.mp3"));
                     break;
                 case '/':
-                    musicList.add(new Media(new File(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICESTROKE.mp3")).toURI().toString()));
+                    musicList.add(ApplicationFileUtils.getFilePath(ApplicationConstants.APPLICATION_NAME, "/VOICESTROKE.mp3"));
                     break;
-//				case ' ':
-//					musicList.add(new Media(new File ("VOICESPACE.mp3").toURI().toString()));
-//					break;
                 default:
                     System.out.println("[KST4ContestApp, warning, letter not defined:] cwLetters = " + Arrays.toString(spellThisWithVoice));
             }
         }
         playMusic();
-//		mediaPlayer.dispose();
 
     }
-    private void playMusic() {
 
-//		System.out.println("Kst4ContestApplication.playMusic");
+    private void playMusic() {
-        if(musicList.peek() == null)
+        if (audioUnavailable.get()) {
-        {
+            musicList.clear();
             return;
         }
-        mediaPlayer = new MediaPlayer(musicList.poll());
+        // Only start a drain loop if none is running; the running loop will pick up new items itself.
-        mediaPlayer.setRate(1.0);
+        if (!playing.compareAndSet(false, true)) return;
-
+        audioThread.submit(() -> {
-        mediaPlayer.setOnReady(() -> {
+            String path;
-            mediaPlayer.play();
+            while ((path = musicList.poll()) != null) {
-            mediaPlayer.setOnEndOfMedia(() -> {
+                if (audioUnavailable.get()) break;
-//				mediaPlayer.dispose();
+                try (FileInputStream fis = new FileInputStream(path);
+                     BufferedInputStream bis = new BufferedInputStream(fis)) {
+                    new Player(bis).play();
+                } catch (IOException | JavaLayerException e) {
+                    audioUnavailable.set(true);
+                    musicList.clear();
+                    System.out.println("[KST4ContestApp, warning, audio playback disabled (could not create media player): " + e + "]");
+                    break;
+                }
+            }
+            playing.set(false);
+            // Items may have been enqueued between the last poll() and playing.set(false);
+            // restart the drain loop if so.
+            if (!musicList.isEmpty() && !audioUnavailable.get()) {
                 playMusic();
-                if (musicList.isEmpty()) {
-//					mediaPlayer.dispose();
             }
         });
-        });
-
     }
 }

src/main/java/module-info.java

@@ -6,6 +6,7 @@ module praktiKST {
 	requires java.sql;
     requires javafx.media;
     requires jdk.jsobject;
+    requires jlayer;
     requires java.net.http;
     requires java.desktop;
 	requires jdk.crypto.ec;