public void setReloadIntervalSeconds(int reloadIntervalSeconds) {
        this.reloadIntervalSeconds = reloadIntervalSeconds;
    }
Sets the interval in seconds at which the property file will be checked for changes and reloaded.  If this is
set to zero or less, property file reloading will be disabled.  If it is set to 1 or greater, then a
separate thread will be created to monitor the property file for changes and reload the file if it is updated.

@param reloadIntervalSeconds the interval in seconds at which the property file should be examined for changes.
                             If set to zero or less, reloading is disabled.
core/src/main/java/org/apache/shiro/realm/text/PropertiesRealm.java