You will have to create an XmlAdapter
like this:
public class LocalDateAdapter extends XmlAdapter<String, LocalDate> {
public LocalDate unmarshal(String v) throws Exception {
return LocalDate.parse(v);
}
public String marshal(LocalDate v) throws Exception {
return v.toString();
}
}
And annotate your field using
@XmlJavaTypeAdapter(value = LocalDateAdapter.class)
See also javax.xml.bind.annotation.adapters.XmlJavaTypeAdapters
if you want to define your adapters on a package level.