Database connection will now always be closed on VM shutdown.

src/main/kotlin/de/fabianonline/telegram_backup/CommandLineController.kt

@@ -115,6 +115,10 @@ class CommandLineController(val options: CommandLineOptions) {
 			// If we reach this point, we can assume that there is an account and a database can be loaded / created.
 			database = Database(file_base, user_manager)
 			
+			Runtime.getRuntime().addShutdownHook(Thread() {
+				database.close()
+			})
+			
 			// Load the settings and stuff.
 			settings = Settings(file_base, database, options)
 			

src/main/kotlin/de/fabianonline/telegram_backup/Database.kt

@@ -662,6 +662,13 @@ class Database constructor(val file_base: String, val user_manager: UserManager)
 		rs.close()
 		return list
 	}
+	
+	fun close() {
+		logger.debug("Closing database.")
+		try { stmt.close() } catch (e: Throwable) { logger.debug("Exception during stmt.close()", e) }
+		try { conn.close() } catch (e: Throwable) { logger.debug("Exception during conn.close()", e) }
+		logger.debug("Database closed.")
+	}
 
 
 	abstract inner class AbstractChat {