private void logSuccess(AuthenticationSuccessEvent event) {
        if (!event.isExistingSession())
            logger.info("{} successfully authenticated from {}",
                    new RequestingUser(event),
                    new RemoteAddress(event.getCredentials()));
        else
            logger.debug("{} successfully re-authenticated their existing "
                    + "session from {}", new RequestingUser(event),
                    new RemoteAddress(event.getCredentials()));
    }
Logs that authentication succeeded for a user.

@param event
    The event describing the authentication attempt that succeeded.
guacamole/src/main/java/org/apache/guacamole/event/EventLoggingListener.java