In an Oracle ATG Web Commerce application, log messages are treated as JavaBeans events. Each log message is encapsulated in an atg.nucleus.logging.LogEvent object. Various types of messages are represented by subclasses of LogEvent, such as ErrorLogEvent and WarningLogEvent. When a component wants to send a logging message, it creates a LogEvent object of the appropriate class, containing the contents of the message. Those contents can include a String message, a Throwable, or both. The component then broadcasts that event object to all listeners.

Components that implement interface atg.nucleus.logging.ApplicationLogging can act as sources of LogEvents. Because GenericService implements ApplicationLogging and Nucleus components extend GenericService, Nucleus components all follow the Oracle ATG Web Commerce logging conventions and can act as sources of error, warning, info and debug LogEvents.