Question

I am using StAX to process a XML file. The document has a DOCTYPE reference to a dtd file

<!DOCTYPE onlineDoc SYSTEM "onlineDoc.dtd">

I get the XML from the internet (am streaming it), and the DTD file lies just next to the XML (but – like the xml – on the remote machine).

Now the DTD contains some entity declarations, that are used in the XML i.e.

<!ENTITY Ntilde "&#209;" ><!-- capital N, tilde -->

I dont provide the DTD yet, so the StAX parser throws an exception saying that the entity Ntilde cannot be resolved.

Q: how do I provide the DTD file to the parser (it would be best, if it could be a stream from teh internet).

Answer 1

With Woodstox everything’s fine. Here’s my snippet (using ClasspathResource class from Spring):

XMLInputFactory xif = XMLInputFactory.newFactory();
xif.setXMLResolver(new XMLResolver() {
  @Override
  public Object resolveEntity(String publicID, String systemID, String baseURI, String namespace) throws XMLStreamException {
    try {
      if ("onlineDoc.dtd".equals(systemID))
        return new ClassPathResource(systemID, getClass()).getInputStream();
    }
    catch (IOException e) {
      return null;
    }
    return null;
  }
});
XMLStreamReader reader = xif.createXMLStreamReader(new ClassPathResource("a.xml", this.getClass()).getInputStream());
while (reader.hasNext()) {
  reader.next();
  if (reader.isCharacters())
    log.info(new String(reader.getTextCharacters()));
}

it works and for:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE onlineDoc SYSTEM "onlineDoc.dtd">
<onlineDoc>
    <test>a &Ntilde; b</test>
</onlineDoc>

prints:

a Ñ b

in Maven use:

<dependency>
   <groupId>org.codehaus.woodstox</groupId>
   <artifactId>woodstox-core-asl</artifactId>
   <version>4.1.2</version>
</dependency>