JAXB @XmlValue Not Working

Question

SampleMessage class:

@XmlRootElement(name = "SampleMessage")
@XmlAccessorType(XmlAccessType.FIELD)
public class SampleMessage {
    @XmlAttribute
    private String type;

    @XmlElement(name = "Content", required = true)
    private Content content;

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public Content getContent() {
        return content;
    }

    public void setContent(Content content) {
        this.content = content;
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    private static class Content {
        @XmlValue
        private String value;

        @XmlAttribute(name = "name")
        private String name;

        public String getValue() {
            return value;
        }

        public void setValue(String value) {
            this.value = value;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }
    }
}

The Spring Boot - Rest Controller I have the follow method which basically just output the same XML form with what we passed, well supposed to be. This is just to check if it is parsing the XML properly.

@PostMapping(consumes = {MediaType.TEXT_XML_VALUE, MediaType.APPLICATION_XML_VALUE})
public String handler(@RequestBody SampleMessage message) {
    StringWriter writer = new StringWriter();

    try {
        JAXBContext jaxbContext = JAXBContext.newInstance(SampleMessage.class);

        Marshaller marshaller = jaxbContext.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(message, writer);
    } catch (JAXBException ex) {
        System.out.println(ex.toString());
    }

    return writer.toString();
}

XML Sample 1: This is the initial XML sample I have:

<?xml version="1.0" encoding="UTF-8"?>
<SampleMessage type="TestType">
  <Content name="TestContent">This is a sample content.</Content>
</SampleMessage>

Output (XML Sample 1): The output I get from the marshaller is this:

<?xml version="1.0" encoding="UTF-8"?>
<SampleMessage type="TestType">
   <Content name="TestContent"/>
</SampleMessage>

Notice that there is no content text in the "Content" element that reads "This is a sample content". However, if I pass additional element Value inside "Content" element then it is able to output correctly.

XML Sample 2

<?xml version="1.0" encoding="UTF-8"?>
<SampleMessage type="TestType">
  <Content name="TestContent"><Value>This is a sample content.</Value></Content>
</SampleMessage>

Correct Output

<?xml version="1.0" encoding="UTF-8"?>
<SampleMessage type="TestType">
   <Content name="TestContent">This is a sample content.</Content>
</SampleMessage>

Any thoughts why is this?

Answer 1

This has resolved. Just noticed that this is a duplicate from my other post, sorry.

JAXB @XmlValue not able to get the text, Not generating empty XML element, and not able to read attribute