Reading XML file to populate text fields

[James Howerton]

The name of this question is read xml and set txtfields using combobox
Hello and Thank you in advance for any assistance.


System info:

netbeans,glassfish,MySQL

The Purpose of this post is:

I am trying to learn how to read an entire XML file and create an array that the selected index from a combo box will populate text Fields using the index to find the appropriate data.


The functionality of this code is:

I presently have a program that uses a combo box, a switch, and text fields set Text code to populate text fields according to the selected Item (the text) from a combo box.


My task is to build an XML file from the hard coded data (hundreds of set text statements. I am in the process of this now and I believe the blocks of tags will be

Code description

pseudo xml

<data>
    <keyName>

    <keyName>
</data>
each keyName tag will have elements to be put in text fields

My question is:

Are there any standards for performing this operation?
Thanks again.
-ceyesumma

Note:
………………………………………………………………………………………………

Code description

[James Howerton]

On creating the xml I realized that I first need to read the entire xml and learn how to find the tag <name> and populate the combo
box.


Could someone help me get started with the proper class or syntax to be using?

I have the first block of XML created and there will be 14 more to follow and my combobox will need to be created and populated properly.

right now I use an array to populate the combo box and an itemStateChanged(ItemEvent box) method. to show a new selected Item
so I would like to know the proper procedure for loading a combo box from xml.

<?xml version="1.0" encoding="utf-8" ?>
<data>
  <keyName>
	<name>
    <![CDATA[C Major]]>
	</name>
    <sigtxt>
      <![CDATA[NO_#_NO_b]]>
    </sigtxt>
    <relatonetxt>
      <![CDATA[g#]]>
    </relatonetxt>
    <paratonetxt>
      <![CDATA[Bn]]>
    </paratonetxt>
    <relasigtxt>
      <![CDATA[NO_#_NO_b]]>
    </relasigtxt>
    <parasigtxt>
      <![CDATA[Bb,Eb,Ab]]>
    </parasigtxt>
    <majtxt>
      <![CDATA[C_Maj]]>
    </majtxt>
    <Itxt>
      <![CDATA[C,E,G,B]]>
    </Itxt>
    <IVtxt>
      <![CDATA[f,A,C,E]]>
    </IVtxt>
    <viiddtxt>
      <![CDATA[B,D,F,A]]>
    </viiddtxt>
    <iiitxt>
      <![CDATA[E,G,B,D]]>
    </iiitxt>
    <vitxt>
      <![CDATA[A,C,E,G]]>
    </vitxt>
    <iitxt>
      <![CDATA[D,F,A,C]]>
    </iitxt>
    <Vtxt>
      <![CDATA[G,B,D,F]]>
    </Vtxt>
    <!--textfield relamin-->
    <relamintxt>
      <![CDATA[a_min_Relative]]>
    </relamintxt>
    <irelatxt>
      <![CDATA[A,C,E,A]]>
    </irelatxt>
    <ivrelatxt>
      <![CDATA[D,F,A,C]]>
    </ivrelatxt>
    <viiDDrelatxt>
      <![CDATA[G#,B,D,F]]>
    </viiDDrelatxt>
    <IIIaugrelatxt>
      <![CDATA[C,E,G#,B]]>
    </IIIaugrelatxt>
    <VIrelatxt>
      <![CDATA[F,A,C,E]]>
    </VIrelatxt>
    <iiddrelatxt>
      <![CDATA[B,D,F,A]]>
    </iiddrelatxt>
    <Vrelatxt>
      <![CDATA[E,G#,B,D]]>
    </Vrelatxt>
    <!--texfield paramin-->
    <paramintxt>
      <![CDATA[c_min_Parallel]]>
    </paramintxt>
    <iparatxt>
      <![CDATA[C,Eb,G,C]]>
    </iparatxt>
    <ivparatxt>
      <![CDATA[F,Ab,C,Eb]]>
    </ivparatxt>
    <viiDDparatxt>
      <![CDATA[B,D,F,Ab]]>
    </viiDDparatxt>
    <IIIaugparatxt>
      <![CDATA[Eb,G,Bb,D]]>
    </IIIaugparatxt>
    <VIparatxt>
      <![CDATA[Ab,C,Eb,G]]>
    </VIparatxt>
    <iiddparatxt>
      <![CDATA[D,F,Ab,C]]>
    </iiddparatxt>
    <Vparatxt>
      <![CDATA[G,B,D,F]]>
    </Vparatxt>
    <!--appegio==========================-->
    <!-- amajtxt.setText("");-->
    <aItxt>
      <![CDATA[C,G,C,E]]>
    </aItxt>
    <aIVtxt>
      <![CDATA[F,C,F,A]]>
    </aIVtxt>
    <aviiddtxt>
      <![CDATA[B,F,B,D]]>
    </aviiddtxt>
    <aiiitxt>
      <![CDATA[E,B,E,G]]>
    </aiiitxt>
    <avitxt>
      <![CDATA[A,E,A,C]]>
    </avitxt>
    <aiitxt>
      <![CDATA[D,A,D,F]]>
    </aiitxt>
    <aVtxt>
      <![CDATA[G,D,G,B]]>
    </aVtxt>
    <!--arelamintxt.setText("");-->
    <raitxt>
      <![CDATA[A,E,A,C]]>
    </raitxt>
    <raivtxt>
      <![CDATA[D,A,D,F]]>
    </raivtxt>
    <raviiDDtxt>
      <![CDATA[G#,D,G#,B]]>
    </raviiDDtxt>
    <raIIIaugtxt>
      <![CDATA[C,G#,C,E]]>
    </raIIIaugtxt>
    <raVItxt>
      <![CDATA[F,C,F,A]]>
    </raVItxt>
    <raiiddtxt>
      <![CDATA[B,F,B,D]]>
    </raiiddtxt>
    <raVtxt>
      <![CDATA[E,B,E,G#]]>
    </raVtxt>
    <!--Car. aparamin);-->
    <paitxt>
      <![CDATA[C,G,C,Eb]]>
    </paitxt>
    <paivtxt>
      <![CDATA[F,C,F,Ab]]>
    </paivtxt>
    <paviiDDtxt>
      <![CDATA[B,F,B,D]]>
    </paviiDDtxt>
    <paIIIaugtxt>
      <![CDATA[Eb,Bb,Eb,G]]>
    </paIIIaugtxt>
    <paVItxt>
      <![CDATA[Ab,Eb,Ab,C]]>
    </paVItxt>
    <paiiddtxt>
      <![CDATA[D,Ab,D,F]]>
    </paiiddtxt>
    <paVtxt>
      <![CDATA[G,D,G,B]]>
    </paVtxt>
  </keyName>
</data>

[Adeel Ansari]

Try looking at JAXP, that sounds appropriate for your case.

[Ulf Dittmer]

The XmlFaq links to several introductory articles regarding XML processing in Java. Using the SAX API it's pretty easy to handle specific tags.

[James Howerton]

I looked at the documentation for an unrelated SAX program and I working on loading a combobox as mentioned above.
I can not seem to get all the pieces in order to just read the keycard.xml and print it out. I guess that is where I start but the example was very confusing. Is it possible to read the xml like this

*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package keycardsxml;

import javax.xml.parsers.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;

import java.util.*;
import java.io.*;

/**
 *
 * @author depot
 */
public class SAXKeyCards extends DefaultHandler {

    public Hashtable tags;
    private String path;
    public String fileName;

    public void startDocument(String namespaceURI, String localName,
            String qName, Attributes atts) throws SAXException {
        String key = localName;
        Object value = tags.get(key);
        if (value == null) {
            tags.put(key, value);
        }

    }

    public static String convertToFileURL(String fileName) {
        String path = new File(fileName).getAbsolutePath();
        return "file:" + path;


    }

    public void endDocument() throws SAXException {
        Enumeration e = tags.keys();
        while (e.hasMoreElements()) {
            String tag = (String) e.nextElement();
            System.out.println("The tags in xml " + tag);
        }
    }
}

public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
       String fileName="keycards.xml";
       SAXParserFactory spf=SAXParserFactory.newInstance();
       spf.setNamespaceAware(true);
       SAXParser saxParser =spf.newSAXParser();

       saxParser=spf.newSAXParser();
       XMLReader xmlReader=saxParser.getXMLReader();
       xmlReader.setContentHandler(new SAXKeyCards());
       SAXKeyCards skc =new SAXKeyCards();
       xmlReader.parse(skc.convertToFileURL(fileName));


       Main m =new Main();
       m.createAndShowGUI();
    }

error:

run:
Exception in thread "main" java.lang.NullPointerException
        at keycardsxml.SAXKeyCards.endDocument(SAXKeyCards.java:42)
        at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endDocument(AbstractSAXParser.java:737)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:515)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:807)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
        at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:107)
        at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1132)
        at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:533)
        at keycardsxml.Main.main(Main.java:55)
Java Result: 1

also my keycard.xml was only found when I put it on the C:/ drive how can I use the keycard.xml if it is in the program package?

[Paul Clapham]

public Hashtable tags;

You'll want to assign a value to this variable before you start using it. Otherwise you will get NullPointerExceptions (as you in fact are).

[James Howerton]

I'm not sure how to assign a value to it. I did not see it set in the example. What values can I put in it?

[James Howerton]

off to a bad start with this one. not helpful examples at all

going to start over with

http://www.totheriver.com/learn/xml/xmltutorial.html

and then try the key words "Java xml tutorial". go figure. probably some good stuff there to.
Thanks for your time.

[Ulf Dittmer]

I'm not sure how to assign a value to it. I did not see it set in the example. What values can I put in it?

Not so much put a value in it, but rather initialize it properly:

public Hashtable tags = new Hashtable();

[James Howerton]

Thanks. I did try that but it seemed like it throws the same exception and it indicates that it was at the end of the file.

I have started over with a new example. Still learning the tools.