gistfile1.java

package com.dengionline.content.faq;

import android.content.Context;
import com.dengionline.R;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

/**
 * User: alex.sorokin@realweb.ru
 * DateTime: 06.02.13 12:54
 */
public class FaqReader {

    private Context mContext;
    private List<FaqCategory> mData;

    protected FaqReader(Context context) {
        mContext = context;
        mData = null;
    }

    public static FaqReader read(Context context) {
        return new FaqReader(context.getApplicationContext());
    }

    public List<FaqCategory> getCategoriesList() {
        lazyLoad();
        return mData;
    }

    public FaqCategory getCategoryById(int id) {
        lazyLoad();
        for (FaqCategory category: mData) {
            if (category.getId() == id) {
                return category;
            }
        }
        return null;
    }

    public FaqArticle getArticleById(int id) {
        lazyLoad();
        for (FaqCategory category: mData) {
            for (FaqArticle article: category.getArticles()) {
                if (article.getId() == id) {
                    return article;
                }
            }
        }
        return null;
    }

    protected void lazyLoad() {
        if (mData == null) {
            try {
                readData();
            } catch (Exception ex) {
                throw new RuntimeException("Unable to parse FAQ", ex);
            }
        }
    }

    protected void readData() throws ParserConfigurationException, SAXException, IOException {
        mData = new LinkedList<FaqCategory>();

        /* Get a SAXParser from the SAXPArserFactory. */
        SAXParserFactory spf = SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();

        /* Get the XMLReader of the SAXParser we created. */
        XMLReader xr = sp.getXMLReader();

        /* Create a new ContentHandler and apply it to the XML-Reader*/
        FaqXmlHandler handler = new FaqXmlHandler();
        xr.setContentHandler(handler);

        xr.parse(new InputSource(
                mContext.getResources().openRawResource(R.raw.faq)
        ));
    }


    class FaqXmlHandler extends DefaultHandler {

        private StringBuilder mNodeValue;
        private int mCategoryOffset;
        private int mArticleOffset;
        private FaqCategory mCurrentCategory;
        private FaqArticle mCurrentArticle;
        private List<FaqArticle> mCurrentArticlesList;

        public FaqXmlHandler() {
            super();
            mNodeValue = new StringBuilder();
            mCategoryOffset = 0;
            mArticleOffset = 0;
            mCurrentArticlesList = new LinkedList<FaqArticle>();
        }

        @Override
        public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
            if ("category".equals(localName)) {
                mCurrentCategory = new FaqCategory();
                mCurrentCategory.setId(mCategoryOffset++);
                mCurrentCategory.setTitle(attributes.getValue("title"));
            } else if ("article".equals(localName)) {
                mCurrentArticle = new FaqArticle();
                mCurrentArticle.setId(mArticleOffset++);
                mCurrentArticle.setTitle(attributes.getValue("title"));
            }
        }

        @Override
        public void endElement(String uri, String localName, String qName) throws SAXException {
            if (mCurrentArticle != null) {
                mCurrentArticle.setContent(mNodeValue.toString());
                mCurrentArticlesList.add(mCurrentArticle);
                mCurrentArticle = null;
            } else if (mCurrentCategory != null) {
                mCurrentCategory.setArticles(mCurrentArticlesList);
                mData.add(mCurrentCategory);
                mCurrentArticlesList = new LinkedList<FaqArticle>();
                mCurrentCategory = null;
            }
            mNodeValue.setLength(0);
        }

        @Override
        public void characters(char[] ch, int start, int length) throws SAXException {
            if (mCurrentCategory != null || mCurrentArticle != null) {
                mNodeValue.append(new String(ch, start, length));
            }
        }

    }

}