Make DocumentBuilder.parse ignore DTD references

Question

When I parse my xml file (variable f) in this method, I get an error

C:\Documents and Settings\joe\Desktop\aicpcudev\OnlineModule\map.dtd (The system cannot find the path specified)

I know I do not have the dtd, nor do I need it. How can I parse this File object into a Document object while ignoring DTD reference errors?

private static Document getDoc(File f, String docId) throws Exception{
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document doc = db.parse(f);


    return doc;
}

Answer 1

I know I do not have the dtd, nor do I need it.

I am suspicious of this statement; does your document contain any entity references? If so, you definitely need the DTD.

Anyway, the usual way of preventing this from happening is using an XML catalog to define a local path for "map.dtd".

Answer 2

hi there,

here's another user who got the same issue : http://forums.sun.com/thread.jspa?threadID=284209&forumID=34

user ddssot on that post says

myDocumentBuilder.setEntityResolver(new EntityResolver() {
          public InputSource resolveEntity(java.lang.String publicId, java.lang.String systemId)
                 throws SAXException, java.io.IOException
          {
            if (publicId.equals("--myDTDpublicID--"))
              // this deactivates the open office DTD
              return new InputSource(new ByteArrayInputStream("<?xml version='1.0' encoding='UTF-8'?>".getBytes()));
            else return null;
          }
});

The user further mentions "As you can see, when the parser hits the DTD, the entity resolver is called. I recognize my DTD with its specific ID and return an empty XML doc instead of the real DTD, stopping all validation..."

Hope this helps.

Answer 3

A similar approach to the one suggested by @anjanb

    builder.setEntityResolver(new EntityResolver() {
        @Override
        public InputSource resolveEntity(String publicId, String systemId)
                throws SAXException, IOException {
            if (systemId.contains("foo.dtd")) {
                return new InputSource(new StringReader(""));
            } else {
                return null;
            }
        }
    });

I found that simply returning an empty InputSource worked just as well?

Answer 4

Try setting features on the DocumentBuilderFactory:

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

dbf.setValidating(false);
dbf.setFeature("http://xml.org/sax/features/namespaces", false);
dbf.setFeature("http://xml.org/sax/features/validation", false);
dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-dtd-grammar", false);
dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);

DocumentBuilder db = dbf.newDocumentBuilder();
...

Ultimately, I think the options are specific to the parser implementation. Here is some documentation for Xerces2 if that helps.