How to get Apache Axiom to correctly report source data line numbers when parsing XML

Question

Here's what I'm doing, essentially copy/paste:ing from the Axiom Quickstart documentation:

public GenericXmlParser(Reader input, String entryElementName, List<DciXmlMapping> dciXmlMappings) {
    this.input = OMXMLBuilderFactory.createOMBuilder(input).getDocument().getXMLStreamReader(false);
    this.dciXmlMappings = dciXmlMappings;
    this.entryElementName = new QName(entryElementName);
}

public FeedEntry next() {
    try {
        while (input.hasNext()) {
            if (input.getEventType() == XMLStreamReader.START_ELEMENT &&
                input.getName().equals(entryElementName)) {

                OMElement element =
                    OMXMLBuilderFactory.createStAXOMBuilder(input).getDocumentElement();
                // Make sure that all events belonging to the element are consumed so that
                // that the XMLStreamReader points to a well defined location (namely the
                // event immediately following the END_ELEMENT event).
                element.build();
                // Now process the element.
                return new FeedEntry(element.getLineNumber(), processEntryElement(element), ImmutableList.<String>of());
            }

            input.next();
        }

        return null;
    }
    catch (XMLStreamException e) {
        throw new ImpException(e);
    }
}

This works, but the problem is, the line number returned by the element.getLineNumber() always seems to be -1. There's not a lot of documentation on the getLineNumber() method, and it's not easy to find the place where a line number is expected to be defined in the source code. Is there some additional configuration I need to do in order to get Axiom to track line numbers?

Answer 1

I suspect the line number information is only as good as the underlying StAX parser can provide. The default StAX implementation in the JRE doesn't do a very good job of this, you might want to try Woodstox instead (should just be a case of including an extra JAR or maven dependency).