Re: looking for simple example to access XML node

From:
"Mich" <comat@videotron.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 8 Apr 2007 13:23:44 -0400
Message-ID:
<gy9Sh.4243$mo3.52671@weber.videotron.net>
"Arne Vajh?j" <arne@vajhoej.dk> wrote in message
news:461919b4$0$90270$14726298@news.sunsite.dk...

Mich wrote:

I have a small XML document and I need to locate an 'led' node according
to the unique 'skew'. I would really appreciate if someone can point me
to an online example of how to do this.

<catalog>
   <led color="Blue" skew='LB1' circumference='5' nm='470' ma='20'
voltage='3.2 ~ 3.8' mcd='6000' angle='10 ~ 20'/>
   <led color="Turquoise" skew='LB1' circumference='5' nm='510' ma='20'
voltage='3.2 ~ 3.8' mcd='6000+' angle='25 to 30'/>
   <led color="Green" skew='LG1' circumference='5' nm='520' ma='20'
voltage='3.2 ~ 3.6' mcd='5000' angle='10 ~ 20'/>
   <led color="Yellow" skew='LY1' circumference='5' nm='585 ~ 595'
ma='20' voltage='1.8 ~ 2.2' mcd='5000' angle='10 ~ 20'/>
   <led color="Red" skew='LR1' circumference='5' nm='640 ~ 645' ma='20'
voltage='1.8 ~ 2.2' mcd='8000' angle='10 ~ 20'/>
   <led color="Red" skew='LR2' circumference='P4' nm='624' ma='70'
voltage='1.8 ~ 2.2' mcd='4500' angle='80'/>
   <led color="Red" skew='LR3' circumference='10' nm='660' ma='20'
voltage='1.8 ~ 2.2' mcd='5000' angle='20'/>
</catalog>


You can use XPath.

Here are an example illustrating the technique:

package april;

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.apache.xml.serialize.OutputFormat;
import org.apache.xml.serialize.XMLSerializer;
import org.apache.xpath.XPathAPI;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class SelextXPath {
    public static void main(String[] args) throws Exception {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.parse(new File("C:\\catalog.xml"));
        Element led =
(Element)XPathAPI.selectSingleNode(doc.getDocumentElement(),
"led[@skew='LY1']");
        OutputFormat fmt = new OutputFormat();
        fmt.setIndenting(true);
        XMLSerializer ser = new XMLSerializer(System.out, fmt);
        ser.serialize(led);
    }
}

Arne


Anne, you are wonderful!

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