JAXB Unmarshall same elements with different attributes (lang)

Question

I have a REST xml feed with the following usage of language differentiation

<name xml:lang="cs">Letní 2001/2002</name>
<name xml:lang="en">Summer 2001/2002</name>

The lang attribute occurs with multiple different elements, other than name. Is there a way for me to unmarshall it easily with only one of the elements based on the selected language? Or get a List or better a Map of both of them?

I know I could possibly do it by creating a different class for each of the elements, but I don't want to have fifty classes just because the language choice, for each resource.

edit: I have not yet considered MOXy, I will probably have to if this can't be done by JAXB alone.

Answer 1

Note: I'm the EclipseLink JAXB (MOXy) lead and a member of the JAXB (JSR-222) expert group.

MOXy allows you to map to an element based on the value of an XML attribute using its @XmlPath extension:

Java Model (Foo)

import javax.xml.bind.annotation.*;
import org.eclipse.persistence.oxm.annotations.XmlPath;

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Foo {

    @XmlPath("name[@xml:lang='cs']/text()")
    private String csName;

    @XmlPath("name[@xml:lang='en']/text()")
    private String enName;

}

Demo

import java.io.File;
import javax.xml.bind.*;

public class Demo {

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

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum17731167/input.xml");
        Foo foo = (Foo) unmarshaller.unmarshal(xml);

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

}

For More Information

• http://blog.bdoughan.com/2011/03/map-to-element-based-on-attribute-value.html
• http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html