Question

I need to create an XML document with the following structure:

<?xml version="1.0" ?> 
<Cancelacion xmlns:xsd="http://www.w3.org/2001/XMLSchema"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             RfcEmisor="VSI850514HX4" 
             Fecha="2011-11-23T17:25:06" 
             xmlns="http://cancelacfd.sat.gob.mx">
    <Folios>
        <UUID>BD6CA3B1-E565-4985-88A9-694A6DD48448</UUID> 
    </Folios>
</Cancelacion>

The structure MUST be that way. But I’m not very familiar with the namespace declaration for the XML Elements. I can correctly generate an XML with the following structure:

<?xml version="1.0" ?> 
<Cancelacion RfcEmisor="VSI850514HX4" 
             Fecha="2011-11-23T17:25:06" 
             xmlns="http://cancelacfd.sat.gob.mx">
    <Folios>
        <UUID>BD6CA3B1-E565-4985-88A9-694A6DD48448</UUID> 
    </Folios>
</Cancelacion>

But the problem is that I can’t get to include the xmls:xsd and xmlns:xsi correctly. The code for properly generating the previously mentioned code is:

// Crear un document XML vacío
DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
dbfac.setNamespaceAware(true);
DocumentBuilder docBuilder;
docBuilder = dbfac.newDocumentBuilder();
Document doc = docBuilder.newDocument();
doc.setXmlVersion("1.0");
doc.setXmlStandalone(true);

Element cancelacion = doc.createElementNS("http://cancelacfd.sat.gob.mx","Cancelacion");
cancelacion.setAttribute("RfcEmisor", rfc);
cancelacion.setAttribute("Fecha", fecha);
doc.appendChild(cancelacion);

Element folios = doc.createElementNS("http://cancelacfd.sat.gob.mx", "Folios");
cancelacion.appendChild(folios);
for (int i=0; i<uuid.length; i++) {
    Element u = doc.createElementNS("http://cancelacfd.sat.gob.mx","UUID");
    u.setTextContent(uuid[i]);
    folios.appendChild(u);
}

Answer 1

You can add additional namespaces by calling setAttributeNS method on the root element
as shown in below example

// get the root element
Element rootElement = xmlDoc.getDocumentElement();

// add additional namespace to the root element
rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:xsd", "http://www.w3.org/2001/XMLSchema");

You can then add elements to a given namespace by using the method like below

// append author element to the document element
Element author = xmlDoc.createElement("xsd:element");

Read this article for more details.