Is there a Java XML API that can parse a document without resolving character entities?

Kaypro II picture Kaypro II · Nov 22, 2009 · Viewed 12.4k times · Source

I have program that needs to parse XML that contains character entities. The program itself doesn't need to have them resolved, and the list of them is large and will change, so I want to avoid explicit support for these entities if I can.

Here's a simple example:

<?xml version="1.0" encoding="UTF-8"?>
<xml>Hello there &something;</xml>

Is there a Java XML API that can parse a document successfully without resolving (non-standard) character entities? Ideally it would translate them into a special event or object that could be handled specially, but I'd settle for an option that would silently suppress them.

Answer & Example:

Skaffman gave me the answer: use a StAX parser with IS_REPLACING_ENTITY_REFERENCES set to false.

Here's the code I whipped up to try it out:

XMLInputFactory inputFactory = XMLInputFactory.newInstance();
inputFactory.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, false);
XMLEventReader reader = inputFactory.createXMLEventReader(
    new FileInputStream("your file here"));

while (reader.hasNext()) {
    XMLEvent event = reader.nextEvent();
    if (event.isEntityReference()) {
        EntityReference ref = (EntityReference) event;
        System.out.println("Entity Reference: " + ref.getName());
    }
}

For the above XML, it will print "Entity Reference: something".

Answer

skaffman picture skaffman · Nov 22, 2009

The STaX API has support for the notion of not replacing character entity references, by way of the IS_REPLACING_ENTITY_REFERENCES property:

Requires the parser to replace internal entity references with their replacement text and report them as characters

This can be set into an XmlInputFactory, which is then in turn used to construct an XmlEventReader or XmlStreamReader. However, the API is careful to say that this property is only intended to force the implementation to perform the replacement, rather than forcing it to not replace them. Still, it's got to be worth a try.