DTD in XML

[Mi Na Mi]

Hello,
I have 2 xml files with dtd defined right inside the xml files. I merge those two files, but the output xml file is completely missed. Is any way to read a definition of dtd inside the xml??
Thank you.

<?xml version='1.0' encoding='us-ascii'?>
<!DOCTYPE Library [
<!ELEMENT Book (Title | Author | Publisher | Date_Published)>
<!ATTLIST Book ISBN CDATA #IMPLIED>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT Author (#PCDATA)>
<!ELEMENT Publisher (#PCDATA)>
<!ELEMENT Date_Published (#PCDATA)>
]>
<Library> 

   <Book  ISBN="8763-343-2343" > 
        <Title>Professional JINI</Title> 
	<Author>Sing Li</Author>
        <Publisher>Wrox Publications</Publisher>
        <Date_Published>22/10/1999</Date_Published>
   </Book>

</Library>

[Paul Clapham]

The parser will take care of reading the DTD, it's not up to you. I don't understand what this "output file" is and what it means for it to be "completely missed", though. Perhaps you could explain in a bit more detail?

[Mi Na Mi]

I merge two xml files, and both of them have dtd declaration, but merged file does not contain a dtd

[Paul Clapham]

That's because you didn't put one there. You didn't say how you merged the two files, but there's no reason why the merged result should have any DTD at all and no reason why a DTD for the merged result should have any relationship with the DTDs for the input files. So if you want the result to have a DTD, it's up to you to make that happen.

[Mi Na Mi]

private static Document merge(InputStream... files) throws SAXException,
			ParserConfigurationException, XPathExpressionException, IOException {
		DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory
				.newInstance();
		docBuilderFactory.setIgnoringElementContentWhitespace(false);
		docBuilderFactory.setExpandEntityReferences(true);
		docBuilderFactory.setNamespaceAware(true);
		DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
		Document base = null;

		base = (Document) docBuilder.parse(files[0]);

		XPathFactory xPathFactory = XPathFactory.newInstance();
		XPath xpath = xPathFactory.newXPath();
		XPathExpression expression = xpath.compile("/"
				+ base.getFirstChild().getNodeName());

		Node results = (Node) expression.evaluate(base, XPathConstants.NODE);
		if (results == null) {

			throw new IOException(files[0]
					+ ": expression does not evaluate to node");

		}

		for (int i = 1; i < files.length; i++) {
			Document merge = null;
			merge = (Document) docBuilder.parse(files[i]);
			Node nextResults = (Node) expression.evaluate(merge,
					XPathConstants.NODE);
			while (nextResults.hasChildNodes()) {
				Node kid = nextResults.getFirstChild();
				nextResults.removeChild(kid);
				kid = base.importNode(kid, true);
				results.appendChild(kid);
			}

		}

		return base;

	}

	private static void print(Document doc, FileOutputStream out)
			throws Exception {
		TransformerFactory transformerFactory = TransformerFactory
				.newInstance();
		Transformer transformer = transformerFactory.newTransformer();
		DOMSource source = new DOMSource(doc);
		Result result = new StreamResult(out);
		// transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "Library");
		transformer.transform(source, result);

	}