Java Tutorials Corner: Modify XML file using DOM Parser

Modify XML file using DOM Parser

In this tutorials we going to see how to modify (add new element, update attribute, update element, delete element )the existing XML document using DOM parser
1. Create Project Called JavaXML.
2. Create package called com.javatutorialscorner.xml.dom under JavaXML.
3. Create Java class called ModifyXML.java under com.javatutorialscorner.xml.dom package.
ModifyXML.java

package com.javatutorialscorner.xml.dom;

import java.io.File;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
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.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class ModifyXML {

 /**
  * @param args
  */
 public static void main(String[] args) {
  // TODO Auto-generated method stub

  try {
   File xmlFile = new File("C:\\jtc\\student.xml");
   DocumentBuilderFactory builderFactory = DocumentBuilderFactory
     .newInstance();
   DocumentBuilder builder = builderFactory.newDocumentBuilder();
   Document document = builder.parse(xmlFile);

   // get first element node of root node
   Node studentNode = document.getElementsByTagName("student").item(0);

   // add new Element
   Element year = document.createElement("year");
   year.appendChild(document.createTextNode("final year"));
   studentNode.appendChild(year);

   // update attribute
   NamedNodeMap arrtMap = studentNode.getAttributes();
   Node attrNode = arrtMap.getNamedItem("id");
   attrNode.setTextContent("ECE-01");

   NodeList nodeList = studentNode.getChildNodes();

   for (int i = 0; i < nodeList.getLength(); i++) {
    Node node = nodeList.item(i);

    if ("lastname".equals(node.getNodeName())) {
     // update text node
     node.setTextContent("k");
    }
    if ("department".equals(node.getNodeName())) {
     studentNode.removeChild(node);
    }
   }

   TransformerFactory factory = TransformerFactory.newInstance();
   Transformer transformer = factory.newTransformer();
   DOMSource domSource = new DOMSource(document);
   StreamResult streamResult = new StreamResult(new File(
     "C:\\jtc\\student.xml"));
   transformer.transform(domSource, streamResult);

  } catch (SAXException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (ParserConfigurationException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (TransformerConfigurationException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (TransformerException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

 }

}

student.xml

Original XML file

<?xml version="1.0" encoding="UTF-8"?>
<college>
<student id="1">
<firstname>Shiva</firstname>
<lastname>Kumar</lastname>
<department>ECE</department>
</student>
<student id="2">
<firstname>Appu</firstname>
<lastname>T</lastname>
<department>CSE</department>
</student>
</college>

Now run the program see the XML file modified.

Modified XML file

<?xml version="1.0" encoding="UTF-8" standalone="no"?><college>
<student id="ECE-01">
<firstname>Shiva</firstname>
<lastname>k</lastname>
<year>final year</year>
</student>
<student id="2">
<firstname>Appu</firstname>
<lastname>T</lastname>
<department>CSE</department>
</student>
</college>