How to Update existing XML File Using Java Swing

Question

Hi,
I am reading XML file and getting keywords into JList. When i add some keywords into JList through textfield and remove keywords JList, then after click on save button it should update xml file. How can i do it ?
Please provide me some code tips for updating xml file
This is the code that i am using for reading XML File:
import javax.swing.*;
import java.awt.event.*;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import java.io.IOException;
import java.util.*;
import java.text.Collator;
import java.util.regex.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import com.cloudgarden.layout.AnchorConstraint;
import com.cloudgarden.layout.AnchorLayout;
public class getKeywords extends JFrame implements ActionListener
static JPanel p;
static JLabel lbl;
static JButton btnSave,btnAdd,btnRemove;
static String path;
static Vector v;
static JList lstCur;
static JTextField txtKey;
Document dom;
static image imgval;
NodeList nodelstImage;
static AnchorLayout anchorLay;
private DefaultListModel lstCurModel;
public getKeywords()
     super("Current Keywords");
    v=new Vector();
    p=new JPanel();
    txtKey=new JTextField(10);
    btnAdd=new JButton("Add");
    btnRemove=new JButton("Remove");
    btnSave=new JButton("Save");
    lbl=new JLabel("Current Keywords");
    lstCurModel=new DefaultListModel();
        lstCur=new JList();
        JScrollPane scr=new JScrollPane(lstCur);
    runExample();
     lstCur.setModel(lstCurModel);
     p.add(lbl);
     p.add(scr);
     p.add(txtKey);
     p.add(btnAdd);
     p.add(btnRemove);
     p.add(btnSave);
     add(p);
     btnAdd.addActionListener(this);
     btnRemove.addActionListener(this);
     btnSave.addActionListener(this);
     setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
public static void main(String arg[])
     getKeywords g=new getKeywords();
     g.resize(250,400);
     g.setVisible(true);     
public void actionPerformed(ActionEvent ae)
     if(ae.getSource()==btnAdd)
          lstCurModel.addElement(txtKey.getText());
     if(ae.getSource()==btnRemove)
          lstCurModel.remove(lstCur.getSelectedIndex());
     if(ae.getSource()==btnSave)
          //Code to Write
     public void runExample()
          //Parse the XML file and get the DOM object
          ParseXMLFile();
          //Get the Detail of the Image Document
          parseImageDocument();
          //Get the Detail of the LML Document
          //parseLMLDocument();
          //System.out.println(lmlval.Title);
     public void ParseXMLFile()
          //Get the Factory
          DocumentBuilderFactory builderFac = DocumentBuilderFactory.newInstance();
          try
               //Using factory get an instance of the Document Builder
               DocumentBuilder builder = builderFac.newDocumentBuilder();
               //parse using builder to get DOM representation of the XML file
               dom = builder.parse("LML.xml");
          catch(ParserConfigurationException pce)
               pce.printStackTrace();
          catch(SAXException sax)
               sax.printStackTrace();
          catch(IOException ioex)
               ioex.printStackTrace();
     public void parseImageDocument()
          //Get the root element
          Element docImgEle = dom.getDocumentElement();
          //Get a nodelist for <Image> Element
          nodelstImage =  docImgEle.getElementsByTagName("Image");
          if(nodelstImage != null && nodelstImage.getLength() > 0)
               for(int i = 0; i < nodelstImage.getLength(); i++)
                    //Get the LML elements
                    Element el = (Element)nodelstImage.item(i);
                    //Get the LML object
                    getImage myImgval = new getImage();
                    imgval = myImgval.getimage(el);
                    v.addElement(new String(imgval.Thumb));
                    String[] x = Pattern.compile(",").split(imgval.Keys);
                    for (int s=0; s<x.length; s++)
                    lstCurModel.addElement(x[s].trim());
                    //System.out.println(x[s].trim());
}     Thanks
Nitin

Answer 1

You should update your DOM document to represent the changes that you want made.
Then, using the Transformation API you simply transform your document onto a stream representing your file. Something like this:
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
// TODO - set indentation amount!
Source source = new DOMSource(dom);
Result result = new StreamResult(file);
transformer.transform(source, result);Hope this helps.