I need to check mandatory/optional elements and attributes in java classes that
are generated by JAXB , according to JAXB specification such as :

" A property is said to have a set value if that value was assigned to it during
unmarshalling or by invoking its mutation method. The value of a property is its
set value, if defined; otherwise, it is the property’s schema specified
default value, if any; otherwise, it is the default initial value for the
property’s base type as it would be assigned for an uninitialized field within
a Java class "

JAXB must to do this check when it wants to marshal java classes to xml file ,
but in practical , it doesnt do it .

if anybody can help me or have any opinion about this problem , please guide me.