Copy a Subtree of Nodes from One DOM Document to Another in Java

    //  w  ww  .  ja v a 2  s  . c  om
import java.io.File;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

public class Main {
  
  public static void main(String[] argv) throws Exception {
    StringReader sr = new StringReader("<tag>java2s.com</tag>");
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder loader = factory.newDocumentBuilder();

    Document document = loader.parse(new InputSource(sr));
   
    NodeList list = document.getElementsByTagName("tag");
    Element element = (Element) list.item(0);

    Document doc2 = factory.newDocumentBuilder().parse(new File("another.xml"));

    Node dup = doc2.importNode(element, true);

    doc2.getDocumentElement().appendChild(dup);

  }
}