How to create an element inside another in java using JAXB?

Question

I have a java code i'm using to create XML file using JAXB, i know how to create root elements and elements but i want to create a child elements from an element like that:

    <root element>
        <element>
               <child element>
               <group of elements and attributes>
               </child element>
        </element>
    </root element>

I'm now only know how to create like this:

    <XmlSource URL="http://local.yahoo.com/rss/restaurants?csz=Cairo,+CA">
        <hostName>local.yahoo.com</hostName>
        <parameters>
            <entry>
                <key>csz</key>
                <value>Cairo,+CA</value>
            </entry>
        </parameters>
        <urlPath>/rss/restaurants</urlPath>
    </XmlSource> 

So, what will i do if i want to put the parameters inside the hostName to be like that :

<XmlSource URL="http://local.yahoo.com/rss/restaurants?csz=Cairo,+CA">
    <hostName name="local.yahoo.com">
             <parameters>
                <entry>
                    <key>csz</key>
                    <value>LosAngelos,+CA</value>
                </entry>
            </parameters>
   </hostName>
    <urlPath>/rss/restaurants</urlPath>
</XmlSource>

And finally that's the java code i use :

The class i put annotations at :

       @XmlRootElement(name= "Source")
       public class XmlConf {

    @XmlElement(name= "Source")

    private URL url;
    private List<String> path = new ArrayList<String>();
    private String urlp;
    private Map<String, String> parameters;
    private String host;


    public URL getUrl() {
        return url;
    }
    @XmlAttribute(name = "URL")
    public void setUrl(URL url) {
        this.url = url;
    }
    @XmlElement
    public List<String> getPath() {
        return path;
    }
    public void setPath(String path) {
        this.path.add(path);
    }
    @XmlElement
    public void setUrlPath(String urlp){
        this.urlp = urlp;
    }
    public String getUrlPath(){
        return urlp;
    }
    @XmlElement(name = "param")
    public void setParameters(Map<String, String> parameters){
        this.parameters = parameters;
    }
    public Map<String, String> getParameters(){
        return parameters;
    }
    public void setHostName(String host){
        this.host = host;
    }
    public String getHostName(){
        return host;
    }
      }

the class i use JAXB in :

    public class ConfList {

    private static final String fileName = "Source.xml";
    List<String> xmlConfList;
    private Object object;

    public ConfList(Object object){
        this.object = object;
    }

    public void addToList() throws IOException, JAXBException {

        File file = new File(object+fileName);
        JAXBContext jaxbContext = JAXBContext.newInstance(XmlConf.class);
        Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

        jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        jaxbMarshaller.marshal(object, file);
        jaxbMarshaller.marshal(object, System.out);

    }
      }

Answer 1

The XML you are looking to produce has what is called mixed content. Mixed content is when a element (hostName) has both text (local.yahoo.com) and element (parameters) content.

<XmlSource URL="http://local.yahoo.com/rss/restaurants?csz=Cairo,+CA">
    <hostName>local.yahoo.com
        <parameters>
            ...
        </parameters>
    </hostName>
</XmlSource>

This can be mapped with JAXB with the @XmlMixed annotation where the text and element content go into one list, but this probably isn't what you want. How about something like this instead?

<XmlSource URL="http://local.yahoo.com/rss/restaurants?csz=Cairo,+CA">
    <host name="local.yahoo.com">
        <parameters>
            ...
        </parameters>
    </host>
</XmlSource>

---

UPDATE

yes, y're right, my bad, i was looking for that form not the one i wrote. how can i make it?

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

You could leverage MOXy's @XmlPath extension for this use case:

import java.net.URL;
import java.util.*;
import javax.xml.bind.annotation.*;
import org.eclipse.persistence.oxm.annotations.XmlPath;

@XmlRootElement(name = "XmlSource")
@XmlType(propOrder={"parameters", "urlp", "path"})
@XmlAccessorType(XmlAccessType.FIELD)
public class XmlConf {

    @XmlAttribute(name="URL")
    private URL url;

    private List<String> path = new ArrayList<String>();

    @XmlElement(name="urlPath")
    private String urlp;

    @XmlPath("hostName/parameters")
    private Map<String, String> parameters;

    @XmlPath("hostName/@name")
    private String host;

}

For More Information

• http://blog.bdoughan.com/2010/07/xpath-based-mapping.html
• http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html

Answer 2

you could go ahead and create a second class "Entry" that would take your attributes "key" and "value" as fields and then change your field in "XmlConf" like so

private List<Entry> parameters;

Cheers //Lutz