// First convert the actual value to the field value
if (fieldClass != valueClass) {
try {
TypeConvertor tc = getTypeConvertorRegistry().getConvertor(
valueClass, fieldClass, null);
internalValue = tc.convert(internalValue);
} catch (MappingException e) {
throw new IllegalArgumentException("Query parameter "
+ (_fieldNum + 1) + " cannot be converted from " + valueClass
+ " to " + paramClass + ", because no convertor can be found.");
}