How to annotate a list using @XmlElement?

Question

I have the following annotation using javax.xml.bind.annotation.XmlElement:

@XmlElement         
public List getKeywords() {
    r         


        

Answer 1

You need to leverage @XmlElementWrapper and @XmlElement.

Java Model

Content

import java.util.List;
import javax.xml.bind.annotation.*;

@XmlRootElement
public class Content {

    private List keywords;

    public Content() {}

    @XmlElementWrapper
    @XmlElement(name="keyword")
    public List getKeywords() {
        return keywords;
    }

    public void setKeywords(List keywords) {
        this.keywords = keywords;
    }  

}

Demo Code

Demo

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

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Content.class);

        List strings = new ArrayList(2);
        strings.add("foo");
        strings.add("bar");

        Content content = new Content();
        content.setKeywords(strings);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(content, System.out);
    }

}

Output

    
        foo
        bar
    

For More Information

Below are links to a couple articles from my blog that provide additional information:

• http://blog.bdoughan.com/2010/09/jaxb-collection-properties.html
• http://blog.bdoughan.com/2012/12/jaxb-representing-null-and-empty.html