Question

i use a xsd schema with an element datatype double like this:

<xsd:element name="value" type="xsd:double"/>

I use the jaxB unmarschaller to create an java class with the appropriate object and attributes. The result looks like this:

protected double value;

Now, the xml data is able to send nullable value elements, but i am not in the position to fit the xsd schema to the datatype Double.class. Is it possible to overwrite the attribute in the java class?

Answer 1

If you cannot modify the XML schema to make the value element nillable, then you could do the following with a JAXB external bindings file:

External Bindings File (binding.xml)

You could use an external bindings file like the following:

<jaxb:bindings 
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
    xmlns:xjc="http://java.sun.com/xml/ns/jaxb/xjc"
    jaxb:extensionBindingPrefixes="xjc"
    version="2.1">
    <jaxb:bindings schemaLocation="double.xsd">
        <jaxb:bindings node="//xs:element[@name='value']">
            <jaxb:property>
                <jaxb:baseType name="java.lang.Double"/>
            </jaxb:property>
      </jaxb:bindings>
   </jaxb:bindings>
</jaxb:bindings>

XML Schema – double.xsd

The above bindings file applies to an XML Schema that looks like the following:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="Root">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="value" type="xs:double"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

XJC Call

xjc -d out -b binding.xml double.xsd

Generated Class

package generated;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {"value"})
@XmlRootElement(name = "Root")
public class Root {

    @XmlElement(required = true, type = Double.class)
    protected Double value;

    public Double getValue() {
        return value;
    }

    public void setValue(Double value) {
        this.value = value;
    }

}