如何使用JAXB编组带有XML根元素的java List？

Question

I have huge list of java Objects, want to marshal that list without a root element, using JAXB. Is it possible to do ?.

I have a list something like this

List<Element> elements = new ArrayList<Element>

Expected Output:
<element>
  ----------
  ---------
</element>
<element>
  ---------
  ---------
<element>

How can I marshal in such a way,

Any reference or hint will be greatly appreciated.

Answer 1

You could iterate over the list marshalling each item individually. You will need to set the JAXB_FRAGMENT property on the Marshaller to prevent the XML header from being written out. You will only need to create the JAXBContext and Marshaller once for this use case.

import java.io.FileOutputStream;
import java.util.*;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Element.class);
        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);

        List<Element> elements = new ArrayList<>();
        elements.add(new Element());
        elements.add(new Element());

        try(FileOutputStream fos = new FileOutputStream("src/forum18509018/out.txt")) {
           for(Element element : elements) {
               marshaller.marshal(element, fos);
           }
        }
    }

}