Java XML DOM Parsing

[Pauldon]

Trying to use DOM in java to parse RSS feeds. I think im going to crack up. Im trying to print everthing out to screen. Here an example of a feed im using.

   
<rss version="2.0">
- <channel>
  <title>University of Ulster | News Releases</title> 
  <link>http://www.ulster.ac.uk</link> 
  <description>Latest News Releases from the University of Ulster, update throughout the day</description> 
  <language>en-gb</language> 
  <copyright>University of Ulster Copyright 2005</copyright> 
  <docs>http://www.webreference.com/xml/column13/2.html</docs> 
  <lastBuildDate>Sat, 22 Apr 2006 11:36:45 GMT</lastBuildDate> 
- <image>
  <title>UU Logo</title> 
  <url>http://www.ulster.ac.uk/images/uu-landscape-rss.jpg</url> 
  <link>http://www.ulster.ac.uk</link> 
  <width>88</width> 
  <height>31</height> 
  <description>University of Ulster</description> 
  </image>
- <item>
  <title>Top Director Takes Centre Stage at Magee</title> 
  <description>The acclaimed director and writer Conall Morrison will visit the University of Ulster’s Magee campus on Wednesday 26th April, as part of the Bank of Ireland ‘Centre Stage’ Series.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2168.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 20 Apr 2006 09:49:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Scholars Lead NI Universities to Gold</title> 
  <description>Current and former University of Ulster Sports Scholars have led NI Universities to gold medals in netball and men’s hockey at the British University Games in Swansea.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2167.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 20 Apr 2006 09:39:00 GMT</pubDate> 
  </item>
- <item>
  <title>Teenage Dancers Wanted</title> 
  <description>The University of Ulster is seeking dance and performance enthusiasts aged 14 ­ 16 to take part in an exciting Easter project at the Jordanstown campus</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2166.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 13 Apr 2006 12:13:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Signs Research Partnership With Top Indian Technology Centre</title> 
  <description>The University of Ulster has signed a Memorandum of Understanding (MoU) with the Indian Institute of Technology, Bombay, in Mumbai, on research cooperation in nanotechnology, wireless technology, network communications and modelling of micro-fluidics.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2165.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 13 Apr 2006 11:37:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Students Score at BUGs</title> 
  <description>University of Ulster sportsmen and sportswomen are flying the flag for Northern Ireland at the British University Games (BUGs) in Swansea this week.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2164.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Wed, 12 Apr 2006 16:54:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Academic gets Prestigious British Academy Award to Research Truth Recovery</title> 
  <description>A University of Ulster academic has been awarded over £70,000 by the British Academy to research official ‘truth recovery’ processes in Northern Ireland.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2162.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Mon, 10 Apr 2006 10:20:00 GMT</pubDate> 
  </item>
- <item>
  <title>Tyrone Inspires UU GAA Ladies Footballers To All-Ireland Title</title> 
  <description>The University of Ulster Jordanstown’s GAA ladies footballers lifted the O’Connor Shield with a comprehensive 1-13 to 1- 02 victory over University College Cork in the All-Ireland Colleges final.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2161.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Mon, 10 Apr 2006 10:07:00 GMT</pubDate> 
  </item>
- <item>
  <title>First Inter Varsity Sports Challenge</title> 
  <description>The first ever inter varsity sports challenge between the University of Ulster and Queen’s University, Belfast ended all square, with both teams winning two disciplines.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2160.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 6 Apr 2006 15:53:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Helps Student To Fast Track Business Success</title> 
  <description>UU student Michael Jenkins is showing the opposition a clean pair of heels with his first business venture.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2159.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 6 Apr 2006 10:52:00 GMT</pubDate> 
  </item>
- <item>
  <title>Hands Off Housing Executive ­ Academic's Call</title> 
  <description>A housing expert from the University of Ulster has issued a “hands off the Housing Executive” call to the Secretary of State.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2158.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 6 Apr 2006 10:12:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Research Targets Food Poisoning Bug</title> 
  <description>One of the most harmful bugs in the food chain is using tiny microbes as ‘Trojan Horses’ to shield itself from attack ­ and the result can be a serious case of food poisoning, according to University of Ulster research presented today.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2157.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Wed, 5 Apr 2006 09:56:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Help School Children Hit The High Note With Roald Dahl</title> 
  <description>Over 100 children from four schools across the North West will take part in a week of music-making as part of an exciting outreach project organised by the University of Ulster, Live Music Now and The Waterside Theatre.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2155.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Tue, 4 Apr 2006 14:53:00 GMT</pubDate> 
  </item>
- <item>
  <title>Universities Go Head-To-Head At Jordanstown</title> 
  <description>Northern Ireland’s two universities, the University of Ulster and Queen’s University Belfast, are set to bring a new level of inter-varsity rivalry to the playing fields tomorrow</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2154.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Tue, 4 Apr 2006 10:58:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Conference Highlights Importance of Modern Languages</title> 
  <description>Students from schools across Northern Ireland took part in a conference at the University’s Coleraine campus last week aimed at raising awareness of the study of modern foreign languages.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2153.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Mon, 3 Apr 2006 15:54:00 GMT</pubDate> 
  </item>
- <item>
  <title>Executive Success for UU Graduate Pamela</title> 
  <description>One of the University of Ulster’s top computer graduates last year has gone on to establish a successful executive recruitment consultancy company in Dublin.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2152.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Mon, 3 Apr 2006 15:42:00 GMT</pubDate> 
  </item>
- <item>
  <title>Prestigious Award For UU Music Student</title> 
  <description>A final-year music student from the University of Ulster has won the prestigious Mostly Modern Young Composer’s Competition 2006.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2151.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Mon, 3 Apr 2006 09:33:00 GMT</pubDate> 
  </item>
- <item>
  <title>Social Work Students Get Insight to Lives of Young Carers</title> 
  <description>Social work students at the University of Ulster got a valuable insight to the difficulties and pressures faced by young carers when children and young people from Barnardo’s performed a series of drama sketches at the Magee Campus.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2149.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Fri, 31 Mar 2006 09:21:00 GMT</pubDate> 
  </item>
- <item>
  <title>University of Ulster Appoints Vice-Chancellor</title> 
  <description>The Council of the University of Ulster has confirmed the appointment of Professor Richard Barnett as the University’s new Vice-Chancellor. The appointment is with immediate effect.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2150.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Fri, 31 Mar 2006 00:00:00 GMT</pubDate> 
  </item>
- <item>
  <title>Annual Report For 2004/5 Presented To Court</title> 
  <description>The Acting Vice-Chancellor, Professor Richard Barnett, has presented the University's annual report for 2004/5 to the University's Court.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2148.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Thu, 30 Mar 2006 10:08:00 GMT</pubDate> 
  </item>
- <item>
  <title>UU Conference Explores Geological Change</title> 
  <description>Postgraduate students from the University’s Coastal Research Group are hosting the British Geomorphological Research Group Postgraduate Symposium at the Coleraine campus this week.</description> 
  <link>http://www.ulster.ac.uk/news/releases/2006/2147.html</link> 
  <author>[e-mail]</author> 
  <pubDate>Wed, 29 Mar 2006 14:41:00 GMT</pubDate> 
  </item>
  </channel>
  </rss>
 
 

[William Brogden]

You really didn't need to post that monsterous listing, just one item posted as code would have been sufficient.
What you needed to post but didn't is exactly what your problem is?
Have you worked through one of the numerous tutorials on DOM parsing such as this one?
What have you tried so far? What happens when you try it?
Bill

[Pauldon]

Right here my sample feed bit smaller and code

  
<?xml version="1.0" encoding="UTF-8" ?> 
<rss version="2.0">
<channel>
<title>test</title> 
<link>http://localhost/test.htm</link> 
<description>test</description> 
<language>en-gb</language> 
<copyright>Paul</copyright> 
<managingEditor>[e-mail]</managingEditor> 
<pubDate>Tue, 18 Apr 2006 12:44:45 GMT</pubDate> 
<cloud domain="localhost" port="8080" path="" registerProcedure="addSubscriber" protocol="XML-RPC" /> 
</channel>
</rss>  
 
 
 
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;
import org.w3c.dom.Document;
 
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
 
public class ShowFileNOW {
 
    public static void main (String args[]) {
        File docFile = new File("feed.xml");

        Document doc = null;
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = db.parse(docFile);
        } catch (java.io.IOException e) {
            System.out.println("Can't find the file");
        } catch (Exception e) {
            System.out.print("Problem parsing the file.");
        }
 
        Element root = doc.getDocumentElement();
        System.out.println("The root element is " + root.getNodeName() + ".\n");
 
        NodeList children = root.getChildNodes();
        System.out.print("There are "+children.getLength()+" child elements.\n");
     
}
}

The result is it says there are three child elements, but there are alot more than three child elements. What's going on. Its the channel tag im thinking how do i get beyond it or set it as the root element.
[ April 22, 2006: Message edited by: Paul Donaghy ]

[Paul Clapham]

The result is it says there are three child elements, but there are alot more than three child elements.

No, unsurprisingly the result is correct (except there are actually three child nodes). The document element is an <rss> element. And under that there are indeed three child nodes:

1. A whitespace text node containing a linefeed character.
2. A <channel> element.
3. Another whitespace text node.

That's it. I suppose your confusion would be partly cleared up if you had an indented listing of the XML document. Then it would be more apparent that the <channel> element itself has quite a few child nodes; many of them are <item> elements that in turn have their own children.

You can traverse this tree structure by writing appropriate DOM code. I won't post any DOM code here because (a) I hate writing DOM code and I would rather use XSLT whenever it's necessary to extract data from XML, and (b) William Brogden already provided a link to a tutorial with DOM code.