Optimzed ShutdownManager for only one clean shutdown

src/main/java/vassistent/App.java

@@ -2,13 +2,10 @@ package vassistent;
 
 import vassistent.bootstrap.ApplicationContext;
 import vassistent.bootstrap.ApplicationInitializer;
+import vassistent.bootstrap.ApplicationShutdownManager;
 import vassistent.controller.AppWindowController;
-import vassistent.service.*;
-import vassistent.util.Logger;
 
 import javax.swing.*;
-import java.io.File;
-
 
 /**
  * Entry point for the virtual health assistant desktop application.
@@ -26,44 +23,13 @@ public class App {
         ApplicationContext context =
                 ApplicationInitializer.initialize();
 
-        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+        ApplicationShutdownManager shutdownManager =
-
+                new ApplicationShutdownManager(context);
-            Logger.info("SYSTEM", "Programm wird beendet");
+        shutdownManager.registerJvmShutdownHook();
-
-            deleteDatabase();
-
-            Logger.shutdown();
-
-        }));
 
         SwingUtilities.invokeLater(() -> {
-            new AppWindowController(context)
+            new AppWindowController(context, shutdownManager)
                     .createAndShowWindow();
         });
     }
-
-    /**
-     * Deletes the runtime SQLite database file if it exists.
-     */
-    private static void deleteDatabase() {
-
-        try {
-
-            File dbFile = new File("data/health.db");
-
-            if (dbFile.exists()) {
-
-                boolean deleted = dbFile.delete();
-
-                if (deleted) {
-                    Logger.info("SYSTEM", "Datenbank gelöscht");
-                } else {
-                    Logger.warn("SYSTEM", "Datenbank konnte nicht gelöscht werden");
-                }
-            }
-
-        } catch (Exception e) {
-            Logger.error("SYSTEM", "DB Löschung fehlgeschlagen", e);
-        }
-    }
 }

src/main/java/vassistent/bootstrap/ApplicationShutdownManager.java

@@ -4,20 +4,36 @@ import vassistent.service.MqttClientService;
 import vassistent.service.ProcessManagerService;
 import vassistent.util.Logger;
 
+import java.io.File;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 /**
- * Coordinates graceful shutdown of MQTT and managed external processes.
+ * Coordinates graceful shutdown of MQTT, managed external processes, and runtime artifacts.
  */
 public class ApplicationShutdownManager {
 
+    private static final String RUNTIME_DB_FILE = "data/health.db";
+
     private final ApplicationContext context;
+    private final AtomicBoolean shutdownStarted = new AtomicBoolean(false);
+    private final AtomicBoolean shutdownHookRegistered = new AtomicBoolean(false);
 
     /**
-     * Creates a shutdown manager and registers a JVM shutdown hook.
+     * Creates a shutdown manager for the provided application context.
      *
      * @param context initialized application context
      */
     public ApplicationShutdownManager(ApplicationContext context) {
         this.context = context;
+    }
+
+    /**
+     * Registers the JVM shutdown hook once for this manager instance.
+     */
+    public void registerJvmShutdownHook() {
+        if (!shutdownHookRegistered.compareAndSet(false, true)) {
+            return;
+        }
 
         Runtime.getRuntime().addShutdownHook(
                 new Thread(this::shutdown)
@@ -28,11 +44,18 @@ public class ApplicationShutdownManager {
      * Executes shutdown steps for managed integrations.
      */
     public void shutdown() {
+        if (!shutdownStarted.compareAndSet(false, true)) {
+            return;
+        }
 
-        Logger.info("SHUTDOWN", "Shutdown Sequencing gestartet");
+        Logger.info("SHUTDOWN", "Shutdown sequencing started");
 
         disconnectMqtt();
         stopExternalProcesses();
+        deleteRuntimeDatabase();
+
+        Logger.info("SHUTDOWN", "Shutdown sequencing finished");
+        Logger.shutdown();
     }
 
     /**
@@ -47,9 +70,9 @@ public class ApplicationShutdownManager {
                 mqtt.disconnect();
             }
 
-            Logger.info("SHUTDOWN", "MQTT getrennt");
+            Logger.info("SHUTDOWN", "MQTT disconnected");
         } catch (Exception e) {
-            Logger.error("SHUTDOWN", "MQTT Shutdown Fehler", e);
+            Logger.error("SHUTDOWN", "MQTT shutdown failed", e);
         }
     }
 
@@ -66,10 +89,36 @@ public class ApplicationShutdownManager {
                 pm.shutdown();
             }
 
-            Logger.info("SHUTDOWN", "Externe Prozesse beendet");
+            Logger.info("SHUTDOWN", "External processes stopped");
 
         } catch (Exception e) {
-            Logger.error("SHUWTDOWN", "Process Shutdown Fehler", e);
+            Logger.error("SHUTDOWN", "Process shutdown failed", e);
+        }
+    }
+
+    /**
+     * Deletes the runtime SQLite database file when present.
+     */
+    private void deleteRuntimeDatabase() {
+
+        try {
+
+            File dbFile = new File(RUNTIME_DB_FILE);
+
+            if (!dbFile.exists()) {
+                return;
+            }
+
+            boolean deleted = dbFile.delete();
+
+            if (deleted) {
+                Logger.info("SHUTDOWN", "Runtime database deleted");
+            } else {
+                Logger.warn("SHUTDOWN", "Runtime database could not be deleted");
+            }
+
+        } catch (Exception e) {
+            Logger.error("SHUTDOWN", "Runtime database deletion failed", e);
         }
     }
 }

src/main/java/vassistent/controller/AppWindowController.java

@@ -12,6 +12,7 @@ import javax.swing.*;
 import java.awt.*;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
+import java.util.Objects;
 
 /**
  * Controls the main window lifecycle and synchronizes UI elements with app state.
@@ -27,10 +28,14 @@ public class AppWindowController {
      * Creates a controller for the main application window.
      *
      * @param context initialized application context with required services
+     * @param shutdownManager shutdown coordinator shared with application bootstrap
      */
-    public AppWindowController(ApplicationContext context) {
+    public AppWindowController(
-        this.context = context;
+            ApplicationContext context,
-        this.shutdownManager = new ApplicationShutdownManager(context);
+            ApplicationShutdownManager shutdownManager
+    ) {
+        this.context = Objects.requireNonNull(context);
+        this.shutdownManager = Objects.requireNonNull(shutdownManager);
         subscribeAppState();
     }