public void run() {
        try {
            reloadPropertiesIfNecessary();
        } catch (Exception e) {
            if (LOGGER.isErrorEnabled()) {
                LOGGER.error("Error while reloading property files for realm.", e);
            }
        }
    }
Destroy reload scheduler if one exists.
core/src/main/java/org/apache/shiro/realm/text/PropertiesRealm.java