List<AbstractField> definedFields = fields.getAllProperties();
for (AbstractField af3 : definedFields)
{
if (af3 instanceof PDFAFieldType)
{
PDFAFieldType field = (PDFAFieldType) af3;
String fName = field.getName();
String fDescription = field.getDescription();
String fValueType = field.getValueType();
if (fName == null || fDescription == null || fValueType == null)
{
throw new XmpParsingException(ErrorType.RequiredProperty,
"Missing field in field definition");
}