Purpose: Provide a means of using annotations to customise the handling of null values
and their xml representation.
This annotation provides the user with a mechanism to customise the way that EclipseLink
handles the reading and writing of null values. This version of NullPolicy makes use of an isSet method to differentiate
between values that were explicitly set to null vs values which are null due to being unset. In
this case the marshal behaviour specified by the nullRepresentationForXml will only be used if
the property was set. A set is only performed during unmarshal if an element was present in the
document. The following values can be specified:
- xsiNilRepresentsNull - This indicates that during unmarshal, an element with an xsi:nil="true"
attribute specified should be unmarshaled as "null" into the object.
- emptyNodeRepresentsNull - This indicates that during unmarshal, an empty node
"<element/>"
should be unmarshalled to as null in the object model.
- nullRepresentationForXml - Determines how a null value in the object model is written out
to XML.
- isSetMethodName - The name of the isSet method on the object owning this property. This
will be invoked to determine if a value of null was set or unset.
- isSetMethodParameters - A list of any parameter values and their types to be passed into
the isSet method when invoked at runtime.
