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bindingjaxbmarshallingfixedrequired

When marshalling, why does JAXB not call getter method for a required attribute with a fixed value?

I have an attribute:

The associated getter method in the generated JAXB object is like this:

public String getUnits(){
    if(units == null) return "metric";
    else return units;
}

getUnits() is not being called by JAXB Marshaller when marshalling and the value is not being set. Why would this not be called?

Solution

  • schema.xsd

    Below is a simplified version of the XML schema that you used to generate your Java classes:

    <?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.example.org/schema" xmlns:tns="http://www.example.org/schema" elementFormDefault="qualified">
    <element name="root">
        <complexType>
            <attribute name="units" fixed="metric"/>
        </complexType>
    </element>
</schema>

    Root

    This will result in a class like the following to be generated. Since @XmlAccessorType(XmlAccessType.FIELD) is specified your JAXB (JSR-222) implementation will get the value form the field instead of accessing the getUnits() method.

    package org.example.schema;

import javax.xml.bind.annotation.*;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "")
@XmlRootElement(name = "root")
public class Root {

    @XmlAttribute(name = "units")
    @XmlSchemaType(name = "anySimpleType")
    protected String units;


    public String getUnits() {
        if (units == null) {
            return "metric";
        } else {
            return units;
        }
    }

    public void setUnits(String value) {
        this.units = value;
    }

}

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