JAXB Create New Element Using binding XML

Question

I'm using XJC to create JAXB annotated Java classes based on a schema file. My issue is that the schema file provided by a third party is missing a field on an object that actually is present in the XML message itself. Is there a way using an XML binding file to create the field? I've been attempting variations on the bindings below to no avail. In this case I'm attempting to create a field called "Bar" on the "Foo" object. It should be of type boolean, but I'm still trying to figure out where to specify that.

<jaxb:bindings
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
    version="2.1">
    <jaxb:globalBindings localScoping="toplevel"/>
    <jaxb:bindings schemaLocation="mySchemaFile.xsd">
        <jaxb:bindings node="//xs:element[@name='Foo']">
            <jaxb:property name="Bar" />
        </jaxb:bindings>
    </jaxb:bindings>
</jaxb:bindings>

Answer 1

The XML schema defines what makes a valid XML document. To the best of my knowledge, JAXB only intends to provide support for parsing/writing valid XML documents. While there are certainly some errors in XML documents that JAXB will read/write if you don't turn on validation, I would say that this is a side-effect of the implementation rather than a design requirement.

I don't know of a way to get JAXB to create the extra property that you are looking for. And certainly not as part of the binding file.

It is possible to get the JAXB-generated classes to extend a class of your choosing, which could have the extra property. Perhaps if you put the right annotations on that property you could get it to be read/written as XML.

I don't know what constraints you have, but given that you want to accept invalid XML documents you might consider grabbing the third-party XSD and maintain your own (extended) version of that. Then you can not deal with trying to work around this issue and you could actually turn on validation.