Help reading xml files

Question

Hi All
I'm trying to read a xml file to get some data.
My xml file looks like this
<?xml version="1.0" encoding="ISO-8859-1"?>
<Reporte>
    <reportYear>2004</reportYear>
    <client>
        <clientCode>4300000001</clientCode>
        <article>
            <articleCode>01101001         </articleCode>
            <articleLastDateBuy>2003-12-03</articleLastDateBuy>
            <articleAvgBuyQty>0</articleAvgBuyQty>
            <articleAvgBuyPeriod>1</articleAvgBuyPeriod>
        </article>
        <article>
            <articleCode>51645AE          </articleCode>
            <articleLastDateBuy>2003-12-09</articleLastDateBuy>
            <articleAvgBuyQty>1</articleAvgBuyQty>
            <articleAvgBuyPeriod>1</articleAvgBuyPeriod>
        </article>
        <article>
            <articleCode>C6578DE          </articleCode>
            <articleLastDateBuy>2003-12-09</articleLastDateBuy>
            <articleAvgBuyQty>1</articleAvgBuyQty>
            <articleAvgBuyPeriod>1</articleAvgBuyPeriod>
        </article>
    </client>
</reporte>Then I wrote this script to read it and I'm trying to show clientCode value as follows:
import java.io.File;
import org.w3c.dom.Document;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
public class ReadXML {
     public static void main(String[] args) {
          try {
               DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
               DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
               Document doc = docBuilder.parse (new File("c:\\javap\\AR3\\ventas2003.xml"));
               // normalize text representation
               doc.getDocumentElement ().normalize ();
               System.out.println ("Root element of the doc is " + doc.getDocumentElement().getNodeName());
               NodeList listOfClients = doc.getElementsByTagName("client");
               int totalClients = listOfClients.getLength();
               System.out.println("Total no of clients : " + totalClients);
               for(int s = 0; s < listOfClients.getLength(); s++) {
                    Node ClientNode = listOfClients.item(s);
                    NodeList clientNodeList = ClientNode.getChildNodes();
                    for (int t = 0; t < clientNodeList.getLength(); t++) {
                         System.out.println("t:" + t + " Value: " + ((Node)clientNodeList.item(t)).getNodeValue().trim());                    
          } catch (SAXParseException err) {
               System.out.println ("** Parsing error" + ", line " + err.getLineNumber () + ", uri " + err.getSystemId ());
               System.out.println(" " + err.getMessage ());
          } catch (SAXException e) {
               Exception x = e.getException ();
               ((x == null) ? e : x).printStackTrace ();
          } catch (Throwable t) {
               t.printStackTrace ();
}But when I run this code I get NullPointerException in the line where I tried to show node value...
Where I'm wrong ?
Thanks in advance
<xl>

Answer 1

Hi
I'm now trying with SAX but I still have problems.
I tried this little first code:
import java.io.*;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
public class EchoXML extends DefaultHandler {
     public static void main(String[] args) {
        DefaultHandler handler = new EchoXML();
        SAXParserFactory factory = SAXParserFactory.newInstance();
        try {
            SAXParser saxParser = factory.newSAXParser();
            saxParser.parse( new File("c:\\javap\\ARVi3\\ventas2003.xml"), handler );
        } catch (Throwable t) {
            t.printStackTrace();
        System.exit(0);
     private void emit(String s) throws SAXException {
               System.out.println(s);
     public void startDocument() throws SAXException {
        emit("<?xml version='1.0' encoding='UTF-8'?>");
        nl();
    public void endDocument() throws SAXException {
            nl();           
     public void startElement(String namespaceURI,
                             String sName, // simple name (localName)
                             String qName, // qualified name
                             Attributes attrs)
    throws SAXException
        nl(); emit("ELEMENT: ");
                  emit("<"+sName);
                  if (attrs != null) {
                      for (int i = 0; i < attrs.getLength(); i++) {
                          emit(" ");
                          emit(attrs.getQName(i) + "=\"" + attrs.getValue(i) + "\"");
                          nl();
                          emit("   ATTR: ");
                          emit(attrs.getLocalName(i));
                          emit("\t\"");
                          emit(attrs.getValue(i));
                          emit("\"");
                  if (attrs.getLength() > 0) nl();
                  emit(">");
    public void endElement(String namespaceURI,
                           String sName, // simple name
                           String qName  // qualified name
    throws SAXException
        emit("</"+sName+">");
     public void characters(char buf[], int offset, int len)
    throws SAXException
        String s = new String(buf, offset, len);
        emit(s);
     private void nl() throws SAXException {
          System.out.println("");
//But I can't see tag names, I receive <>2004-02-12<>...
Also, I want to know how shall I do to retrieve a specific tags and their childs...
Thanks in advance
<xl>