why XMLEncoder is not encoding all public properties?

[getstarted]

I have the following properties (both getters and setters are public)
String fieldID = null;
String validationCode = null;
String vaidationMessage = null;
String value = null;
boolean changeIndicator = true;

But when I encode, it is not encoding validationMessage and changeIndicator. I am not directly encoding this object, but this is part other object and I am trying to encode that object.

Edit: These are not being set through constructor.. I have another method which sets 2, 3rd and 4th parameters