How to update/change the value of elements in an xml file?

Question

Hi Everyone,
Could any one of u tell me how to update the value of elements in an XML file, using java? The reason is i want to use an XML file as a data source (i.e. more or less like a database), without using any RDBMS, for simple applications such as to read a record and update the record. By the way, my XML file will have only one record, such as the current weather information, with fields such as temperature, humdity etc. for 1 city only.
Thanks in advance.

Answer 1

Here is a solution how to check a particular value or element name in an xml and update the changes e to an xml.
Sample.xml
<URLConstructor>
<application name="cp_outage">
<resource>hello</resource>
<value>val</value>
</application>
<application name="cp_outage">
<resource>hello</resource>
<value>val</value>
</application>
</URLConstructor>
XMLWriter.java
package com;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.DOMBuilder;
import org.jdom.output.XMLOutputter;
// used for printing
import org.apache.xml.serialize.XMLSerializer;
import org.jdom.output.XMLOutputter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.List;
class XMLWriter{
public void update(File fileName)
try {
          DOMBuilder domBuilder=new DOMBuilder();
          Document doc=domBuilder.build(fileName);
          Element element=doc.getRootElement();
          getChildren(element);
          writeToXML(doc,fileName);
          getChildren(element);
} catch (Exception e) {
e.printStackTrace();
     * @param doc
     private void writeToXML(Document document,File filePath)
               XMLOutputter xmloutputter = new XMLOutputter();
                    try
                         FileOutputStream fileOutputStream = new FileOutputStream(filePath);
                         xmloutputter.output(document, fileOutputStream);
                         fileOutputStream.close();
                    catch (FileNotFoundException e)
                         e.printStackTrace();
                    catch (IOException e)
                         e.printStackTrace();
     public void getChildren(Element element)
                    if(!element.hasChildren())
                         return;
                    List childrenList = element.getChildren();
                    Iterator itr=childrenList.iterator();
                    while(itr.hasNext())
                         Element childElement=(Element) itr.next();
                         if(childElement.hasChildren())
                                   getChildren(childElement);
//                                   System.out.println("Name "+childElement.getName());
//                                   System.out.println("Value "+childElement.getText());
                                   if(childElement.getText().equals("hello") || (childElement.getName().equals("resource")))
                                        updateInfo(childElement,"New_Resource","AddedText");
     * @param childElement
     * @param string
     * @param string2
     private void updateInfo(Element element, String elementName, String value)
          element.setName(elementName);
          element.setText(value);          
static public void main(String[] args)
XMLWriter xmlWriter=new XMLWriter();
xmlWriter.update(new File("c:/sample.xml"));
After execution the file will be changed to
<URLConstructor>
<application name="cp_outage">
<New_Resource>AddedText</New_Resource>
<value>val</value>
</application>
<application name="cp_outage">
<New_Resource>AddedText</New_Resource>
<value>val</value>
</application>
</URLConstructor>
Regards,
Maheswar