How to instantiate an empty element with JAXB

Question

I use JAXB to create XML messages. The XML I need to create is (for the sake of simplicity):

Answer 1

I wanted the same thing, effectively

rather than

during the xml serialization process.

Since a null value - rather than an empty string - will produce the correct result, I modified my setter method to set the value explicitly to null:

public void setHeader(String header) {
    this.header = "".equals(header) ? null : header;
}