Re: DocumentBuilder's parse method is not able to read a tag such as this one <weight/>

From:
"BeGreen" <JenniferCheng99@yahoo.com>
Newsgroups:
comp.lang.java.programmer
Date:
13 Aug 2006 16:28:43 -0700
Message-ID:
<1155511723.372487.139790@b28g2000cwb.googlegroups.com>
Hi Guys,

Thanks for your help. I finally fixed it, with your sample codes.

Roland de Ruiter wrote:

On 13-8-2006 19:53, BeGreen wrote:

Hi Michael,

Yes, I can be able to parse the xml data, but my program is failing
when executing the code below, to retrieve the Record where there is
this empty tag without a value, <weight/>

<weight>something</weight> can be retrieved, but why not this one
<weight/>

As far as I am concerned <weight/> is a well-formed empty tag, and it
should be retrieved successfully!

There must an XML/Jave API to be able to retrieve it!

..............................................................................................

if (node.getNodeName()=="weight") {
String weightvalue = node.getFirstChild().getNodeValue();
}

-----------------------------------------------------------------------------------------------


An empty tag has no child nodes. Find out how many children a node has
by using node.getChildNodes().getLength();
See Michael's example below in which I've extended to obtain the value
of the <weight> tags.

import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;

public class XMLTest {
     public static void main(String[] args) throws Exception {
         String xml = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>\n"
                 + "<root>\n"
                 + " <Record>\n"
                 + " <PartNo>01</PartNo>\n"
                 + " <weight/>\n"
                 + " </Record>\n"
                 + " <Record>\n"
                 + " <PartNo>2</PartNo>\n"
                 + " <weight>A</weight>\n"
                 + " </Record>\n" + "</root>";
         System.out.println(xml);
         byte data[] = xml.getBytes("ISO-8859-1");
         ByteArrayInputStream is = new ByteArrayInputStream(data);

         DocumentBuilderFactory factory =
             DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document doc = builder.parse(is);
         is.close();
         inspect(doc);
         System.out.println("Done.");
     }

     private static void inspect(Node node) {
         if (node != null) {
             if ("weight".equals(node.getNodeName())) {
                 String weightValue;
                 NodeList children = node.getChildNodes();
                 if (children.getLength() > 0) {
                     weightValue = node.getFirstChild().getNodeValue();
                 }
                 else
                 {
                     weightValue = "#empty#";
                 }
                 System.out.println(node + " " + weightValue);
             }

             NodeList children = node.getChildNodes();
             int n = children.getLength();
             for (int i = 0; i < n; i++) {
                 inspect(children.item(i));
             }
         }
     }
}

--
Regards,

Roland

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