Most application services need a way to report events that occur during the operation of that service. In ATG products, this is handled by having the component fire LogEvents. These LogEvents are then broadcast to listeners that can handle those events. The ATG platform comes with a set of listener services that can send LogEvents to files, to the screen, to databases, etc.
With this setup, components only have to worry about what logging events they want to report, while other components worry about sending those events to their eventual destinations. Like everything else in Nucleus, the connections between components and their logging destinations are described by properties files.
For the convenience of programmers, the ATG platform uses a standard logging interface called atg.nucleus.logging.ApplicationLogging. This interface defines the listener, adding and removing methods needed to define a component as a source of LogEvents. This interface also defines a set of properties for indicating what level of logging has been turned on. For example, the loggingWarning property describes whether a component should be emitting warning log messages. See Using ApplicationLogging in the Logging and Data Collection chapter for more information.
