Copying a Subtree of Nodes in a DOM Document

e525. Copying a Subtree of Nodes in a DOM Document

    // Obtain an element; the following method is implemented in
   //  e510 The Quintessential Program to Create a DOM Document from an XML File     Document doc = parseXmlFile("infilename.xml", false);
   NodeList list = doc.getElementsByTagName ("entry");
   Element element = (Element)list.item(0);
  
   // Make a copy of the element, including any child nodes
   Element dup = (Element)element.cloneNode(true);
  
   // Insert the copy immediately after the cloned element
   element.getParentNode().insertBefore(dup, element.getNextSibling());

This is the sample input for the example:

    <root>
       <entry attr="value">
           a<i>b</i>c
       </entry>
   </root>

This is the resulting XML:

    <?xml version="1.0" encoding="UTF-8"?>
   <root>
       <entry attr="value">
           a<i>b</i>c
       </entry>
       <entry attr="value">
           a<i>b</i>c
       </entry>
   </root>

My samples: copy a whole tree from one xml file to aother xml file doc:

private static Document buildReturnDoc(long txnID, Document doc){
Document document=null;
DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
document = builder.newDocument();

Element root = (Element) document.createElementNS(null, "transaction");
root.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns", "dncg");
document.appendChild(root);
root.setAttribute("trxID", String.valueOf(txnID));

Node node=document.importNode(getIncomingRequestElement(doc), true);
root.appendChild(node);

//DNCGUtils.writeXmlDoc("Transaction-output.xml", doc);
} catch (ParserConfigurationException pce) {
// Parser with specified options can't be built
pce.printStackTrace();
}

return document;
}


private static Element getIncomingRequestElement(Document doc){

Element fd=null;
Element dup=null;
fd=(Element) doc.getElementsByTagName("incoming-request").item(0);
dup=(Element) fd.cloneNode(true);

return dup;
}