RssHandler.java

package com.nerdability.android.rss.parser;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import android.net.Uri;

import com.nerdability.android.rss.domain.Article;


public class RssHandler extends DefaultHandler {

	// Feed and Article objects to use for temporary storage
	private Article currentArticle = new Article();
	private List<Article> articleList = new ArrayList<Article>();

	// Number of articles added so far
	private int articlesAdded = 0;

	// Number of articles to download
	private static final int ARTICLES_LIMIT = 15;

	//Current characters being accumulated
	StringBuffer chars = new StringBuffer();


	public List<Article> getArticleList() {
		return articleList;
	}



	/* 
	 * This method is called everytime a start element is found (an opening XML marker)
	 * here we always reset the characters StringBuffer as we are only currently interested
	 * in the the text values stored at leaf nodes
	 * 
	 * (non-Javadoc)
	 * @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
	 */
	public void startElement(String uri, String localName, String qName, Attributes atts) {
		chars = new StringBuffer();
	}



	/* 
	 * This method is called everytime an end element is found (a closing XML marker)
	 * here we check what element is being closed, if it is a relevant leaf node that we are
	 * checking, such as Title, then we get the characters we have accumulated in the StringBuffer
	 * and set the current Article's title to the value
	 * 
	 * If this is closing the "entry", it means it is the end of the article, so we add that to the list
	 * and then reset our Article object for the next one on the stream
	 * 
	 * 
	 * (non-Javadoc)
	 * @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
	 */
	public void endElement(String uri, String localName, String qName) throws SAXException {

		if (localName.equalsIgnoreCase("title")){
			currentArticle.setTitle(chars.toString());
		} else if (localName.equalsIgnoreCase("description")){
			currentArticle.setDescription(chars.toString());
		} else if (localName.equalsIgnoreCase("pubdate")){
			currentArticle.setPubDate(chars.toString());
		} else if (localName.equalsIgnoreCase("published")){
			currentArticle.setPubDate(chars.toString());
		} else if (localName.equalsIgnoreCase("id")){
			currentArticle.setGuid(chars.toString());
		} else if (localName.equalsIgnoreCase("author")){
			currentArticle.setAuthor(chars.toString());
		} else if (localName.equalsIgnoreCase("link")){
			try {
				currentArticle.setUrl(new URL(chars.toString()));
			} catch (MalformedURLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} else if (localName.equalsIgnoreCase("content")){	
			currentArticle.setEncodedContent(chars.toString());
		} else if (localName.equalsIgnoreCase("entry")){
			
		} 


		// Check if looking for article, and if article is complete
		if (localName.equalsIgnoreCase("entry")) {

			articleList.add(currentArticle);

			currentArticle = new Article();

			// Lets check if we've hit our limit on number of articles
			articlesAdded++;
			if (articlesAdded >= ARTICLES_LIMIT)
			{
				throw new SAXException();
			}
		}
	}


	/* 
	 * This method is called when characters are found in between XML markers, however, there is no
	 * guarante that this will be called at the end of the node, or that it will be called only once
	 * , so we just accumulate these and then deal with them in endElement() to be sure we have all the
	 * text
	 * 
	 * (non-Javadoc)
	 * @see org.xml.sax.helpers.DefaultHandler#characters(char[], int, int)
	 */
	public void characters(char ch[], int start, int length) {
		chars.append(new String(ch, start, length));
	}
}