public final class OmittedWhenNullMarker
extends java.lang.RuntimeException
The OmittedWhenNullMarker is a special kind of runtime
exception that can be declared in the throws clause
of a getter method to indicate to the marshalling code that
the property represented by the getter is not to be persisted at
all if the property value is null.
Java's ability to annotate methods with metadata at compile-time
is very limited. BeanInfo classes tend to be cumbersome and the
information in the BeanInfo class can often be overlooked since
the BeanInfo code is usually in a separate file and sometimes
even in a separate package. By using a "marker exception" in
the throws clause of the getter, the fact that the getter
represents a transient property is readily apparent, especially
once the purpose OmittedWhenNullMarker is understood.