Question

I have created an XML schema (foo.xsd) and used xjc to create my binding classes for JAXB. Let’s say the root element is collection and I am writing N document objects, which are complex types.

Because I plan to write out large XML files, I am using Stax to write out the collection root element, and JAXB to marshal document subtrees using Marshaller.marshal(JAXBElement, XMLEventWriter). This is the approach recommended by jaxb’s unofficial user’s guide.

My question is, how can I validate the XML while it’s being marshalled? If I bind a schema to the JAXB marshaller (using Marshaller.setSchema()), I get validation errors because I am only marshalling a subtree (it’s complaining that it’s not seeing the collection root element”). I suppose what I really want to do is bind a schema to the Stax XMLEventWriter or something like that.

Any comments on this overall approach would be helpful. Basically I want to be able to use JAXB to marshal and unmarshal large XML documents without running out of memory, so if there’s a better way to do this let me know.

Answer 1

Some Stax implementations seem to be able to validate output. See the following answer to a similar question:

Using Stax2 with Woodstox