How do I insert an internal dtd into an xml file using Java

How do I insert an internal dtd into an xml file using Java

I have the following test code which reads in an XML file into a DOM Document, then writes it out again. I would like the output files to end up being the same as the input file.

public class DomToXml {
Document document;

void process() {
    document = parseXmlFile("dat/input.xml");
    writeXmlFile(document, "dat/output.xml");
}

void writeXmlFile(Document document, String fileName) {
    try {
        Source source = new DOMSource(document);
        File file = new File(fileName);
        Result result = new StreamResult(file);
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
        transformer.setOutputProperty(OutputKeys.ENCODING, "ISO-8859-1");
        DocumentType documentType = document.getDoctype();
        if (documentType != null) {
            transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, documentType.getSystemId());
            transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, documentType.getPublicId());
        }
        transformer.transform(source, result);
    } catch (Exception e) {
        e.printStackTrace();
        System.exit(-1);
    }
}

Document parseXmlFile(String filename) {
    DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
    documentBuilderFactory.setNamespaceAware(true);
    documentBuilderFactory.setXIncludeAware(true);
    documentBuilderFactory.setExpandEntityReferences(true);
    documentBuilderFactory.setValidating(false);
    DocumentBuilder documentBuilder;
    try {
        documentBuilder = documentBuilderFactory.newDocumentBuilder();
        documentBuilder.setErrorHandler(new MyErrorHandler());
        documentBuilder.setEntityResolver(new MyEntityResolver());
        return documentBuilder.parse("file:" + filename);
    } catch (Exception e) {
        e.printStackTrace();
        System.exit(-1);
    }
    return null;
}

public static void main(String[] args) {
    DomToXml a = new DomToXml();
    a.process();
    System.out.println("Done!");
}

}

The Input file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE root PUBLIC "NONE"
  "none.dtd" [
  <!ENTITY foo "bar">
]>
<root id="TEMPLATE" xreflabel="TEMPLATE-&foo;">
</root>

The output:

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<!DOCTYPE root PUBLIC "NONE" "none.dtd">
<root id="TEMPLATE" xreflabel="TEMPLATE-bar">
</root>

As you can see, the dtd along with the entity information is not being outputed. How do i fix this?

As a secondary question, how do I stop the transformation of the entity. i.e. I want the output file to contain TEMPLATE开发者_开发知识库-&foo; rather than TEMPLATE-bar.

Thanks,

Wayne.

I can get the DTD entity declaration in the output, but haven't worked out how to preserve the entity itself:

DOMImplementationLS domImplementation = (DOMImplementationLS) DOMImplementationRegistry
    .newInstance().getDOMImplementation("LS");
LSSerializer lsSerializer = domImplementation.createLSSerializer();
System.out.println(lsSerializer.writeToString(document));

The simple way for converting String to DOM and vice versa is probably presents here:

http://famulatus.com/ks/programming/java/item/335-convert-xml-dom-to-string-and-string-to-xml-dom.html