File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes XML and Related Technologies and the fly likes Updating Xml Element values Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Engineering » XML and Related Technologies
Bookmark "Updating Xml Element values " Watch "Updating Xml Element values " New topic

Updating Xml Element values

S Rajagopal

Joined: Jun 17, 2010
Posts: 9
Hi all,

I am writing a java code to update xml file elements . I need to know how to write the changes to the xml file.I used the setNodevalue() method but the change isn't reflecting in the xml file.I am parsing the xml file using sax parser.I am comparing an arraylist containing the tags that need to be updated with the elements of the xml file .In case of a match i need to update the xml file elements with values in a 2nd arraylisy(the index of the tags and its value are same in both arraylist).The xml file is not updated because the setnodevalue() in my code is updating the arraylist instead i should write the changes to the xml file.

Kindly share your suggestions and help me.

For reference

The following is a rough code that i have written,if it works i can use the functionality as part of an application that i am developing

package com;

import java.util.ArrayList;
import java.util.List;

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;

public class Test {
String s1[] = null;
static ArrayList<String> tagvalue = new ArrayList<String>();
static ArrayList<String> l = new ArrayList <String>();
NodeList fstNmElmntLst =null;
static Element fstElmnt =null;

public static void main(String args[]) {

// tag values that need to be compared


//arraylist containing values that need to be updated
tagvalue.add("NEW JERSEY CITY");
try {
File file = new File("C:\\Documents and Settings\\ravi\\Desktop\\test.xml");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(file);
System.out.println("Root element "+ doc.getDocumentElement().getNodeName());
NodeList nodeLst = doc.getElementsByTagName("HeadQuaters");
Node fstNode = nodeLst.item(0);

if (fstNode.getNodeType() == Node.ELEMENT_NODE) {
Element fstElmnt = (Element) fstNode;
for (int i = 0; i < l.size(); i++) {

NodeList fstNmElmntLst = fstElmnt.getElementsByTagName((String) l.get(i));
Element fstNmElmnt = (Element) fstNmElmntLst.item(0);
NodeList fstNm = fstNmElmnt.getChildNodes();

System.out.println(" current xml node value:"+ ((Node) fstNm.item(0)).getNodeValue());

// the following line is updating the node but not the required xml file element
System.out.println(" updated xml node value:"+ ((Node) fstNm.item(0)).getNodeValue());

// need to proceed from here to update the xml




catch (Exception e) {


Thanks in advance

Paul Clapham

Joined: Oct 14, 2005
Posts: 19973

Ah, that's a very common question for DOM beginners. Have a look at the Ranch's XmlFaq; you'll see there's a link which tells you how to write a Document to a File.

There's a lot more links there, too. You might want to have a look at some of the others.
I agree. Here's the link:
subject: Updating Xml Element values
It's not a secret anymore!