Register an instance of an implementation of this class with a
Marshaller to externally listen
for marshal events.
This class enables pre and post processing of each marshalled object.
The event callbacks are called when marshalling from an instance that maps to an xml element or
complex type definition. The event callbacks are not called when marshalling from an instance of a
Java datatype that represents a simple type definition.
External listener is one of two different mechanisms for defining marshal event callbacks.
See Marshal Event Callbacks for an overview.
Marshaller.setListener(Listener), Marshaller.getListener()