Question

1.) I have an XSD file (I have no control over) that I converted to object model using JAXB

2.) I have a database extract in XML format. The XML element tag names are strictly the field names of the table

3.) I mapped the xml elements to the Java class using annotations.

Question: Is there a way to maintain the element names in the XSD file, and JUST extract the value of the xml elements.

JAXB annotated class:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "Item", propOrder = {
    "code",
    "name",
    "price"
})
@XmlRootElement(name="inventory")
public class Item {

    @XmlElement(name="catalog_num", required = true)
    protected String code;

    @XmlElement(name="catalog_descrip", required = true)
    protected String name;

    @XmlElement(name="prod_price")
    protected double price;


    public String getCode() {
        return code;
    }
//etc

An excerpt of the database xml file:

<?xml version="1.0"?>
<inventory>
          <catalog_num>I001</catalog_num>
          <catalog_descrip>Descriptive Name of Product</catalog_descrip>
          <prod_price>11200</prod_price>
</inventory>

The result I need to get after marshaling the above xml file is:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Item>
    <code>I001</code>
    <name>Descriptive Name of Product</name>
    <price>11200.0</price>
</Item>

In the above code, I have tried annotating the methods instead of the fields, but I yield the same result. I just want the value extracted from the xml elements, but not change the element names.

I hope I am making sense.

Answer 1

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

MOXy offers an extension where you can apply a second XML binding via an XML document. This binding document can either be used to add metadata, or when xml-mapping-metadata-complete="true" completely replace the metadata supplied by the JAXB annotations on the Java model;

<?xml version="1.0"?>
<xml-bindings
    xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm"
    package-name="forum6838882" 
    xml-mapping-metadata-complete="true">
    <java-types>
        <java-type name="Item" xml-accessor-type="FIELD">
            <xml-root-element name="Item"/>
        </java-type>
    </java-types>
</xml-bindings>

The bindings file is passed as a parameter when creating the JAXBContext:

Map<String, Object> properties = new HashMap<String, Object>();
properties.put(JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY, "forum6838882/binding.xml");
JAXBContext resultJC = JAXBContext.newInstance(new Class[] {Item.class}, properties);

To solve your issue you could create one JAXBContext to handle the database document (using the annotated classes), and create a second JAXBContext to handle the result format using the MOXy binding file. Below is how this would look:

package forum6838882;

import java.io.File;
import java.util.HashMap;
import java.util.Map;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

import org.eclipse.persistence.jaxb.JAXBContextFactory;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext databaseJC = JAXBContext.newInstance(Item.class);
        Unmarshaller databaseUnmarshaller = databaseJC.createUnmarshaller();
        File databaseXML = new File("src/forum6838882/database.xml");
        Item item = (Item) databaseUnmarshaller.unmarshal(databaseXML);

        Map<String, Object> properties = new HashMap<String, Object>();
        properties.put(JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY, "forum6838882/binding.xml");
        JAXBContext resultJC = JAXBContext.newInstance(new Class[] {Item.class}, properties);
        Marshaller resultMarshaller = resultJC.createMarshaller();
        resultMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        resultMarshaller.marshal(item, System.out);
    }
}

For a More Detailed Example See:

• http://blog.bdoughan.com/2011/09/mapping-objects-to-multiple-xml-schemas.html