Logic error in stop() method of OSGi bundle activator

The code

    if (DriverManager.getDriver("jdbc:mariadb:") != null) {

      SchedulerServiceProviderHolder.close();

    }

assumes that getDriver returns null if the driver is not found. It does not, it never returns null. It throws a SQLException with message "No suitable driver" and error code 08001.
Please replace by a try-catch clause.