Java HTML / XML How to - Copy a Node from One Parse Tree into Another








Question

We would like to know how to copy a Node from One Parse Tree into Another.

Answer

import java.io.StringReader;
import java.io.StringWriter;
/*w w w . ja va 2 s .c o m*/
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

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

public class Main {
  public static String getXMLData() {
    return "<a><person  number='' dept=''><name>myName</name></person></a>";
  }

  public static void main(String[] argv) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    Document doc = factory.newDocumentBuilder().parse(
        new InputSource(new StringReader(getXMLData())));

    importName(doc,doc);

    System.out.println(documentToString(doc));

  }

  public static void importName(Document doc1,Document doc2) {
    Element root1 = doc1.getDocumentElement();
    Element personInDoc1 = (Element)root1.getFirstChild();

    Node importedPerson = doc2.importNode(personInDoc1,true);

    Element root2 = doc2.getDocumentElement();
    root2.appendChild(importedPerson);
  }

  public static String documentToString(Document document) {
    try {
      TransformerFactory tf = TransformerFactory.newInstance();
      Transformer trans = tf.newTransformer();
      StringWriter sw = new StringWriter();
      trans.transform(new DOMSource(document), new StreamResult(sw));
      return sw.toString();
    } catch (TransformerException tEx) {
      tEx.printStackTrace();
    }
    return null;
  }
}

The code above generates the following result.