JAXB，从XML解组，缺少字段为null

Question

XML inputs are unmarshalled with moxy using namespaces with @XmlPath . It works fine. However, if a field from the xml is missing, then it is assigned an empty string after unmarshalling is done. I would like however null to be assigned in such cases. I put two simplified XML examples down below. I would like the element b to be assigned an empty string in the first example while a null value in the second example. Do you have any ideas? Thank you also in advance.

e.g. 1.
<ft:root>
    <ft:a>hhh</ft:a>
    <ft:b></ft:b>
</ft:root>


e.g. 2.
<ft:root>
    <ft:a>hhh</ft:a>
</ft:root>

Answer 1

The Problem was solved after I did a mvn clean install. Sorry for bothering you.