/**

  * Copyright 2009 Timothy Johnston Licensed under the Apache License, Version 2.0 (the "License"); you may not use this

  * file except in compliance with the License. You may obtain a copy of the License at

  * 

  * http://www.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on

  * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the

  * specific language governing permissions and limitations under the License.

  */

 package com.timjohnstondev.unitconverter.logic;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.logging.Logger;

 import javax.xml.parsers.ParserConfigurationException;

 import javax.xml.parsers.SAXParser;

 import javax.xml.parsers.SAXParserFactory;

 import org.xml.sax.SAXException;

 import org.xml.sax.helpers.DefaultHandler;

 /**

  * Parser that parses a XML file, but the important part is the {@link ConversionFactorParserHandler}. The XML file is

  * defined in this class and should probably allow to select different data source.

  */

 public class ConversionFactorParser

 {

   private static Logger logger = Logger.getLogger(ConversionFactorParser.class.getName());

   private final String dataFileName = "/com/timjohnstondev/unitconverter/model/ConversionFactors.xml";

   private DefaultHandler handler;

   private SAXParser saxParser;

   /**

    * Constructs and initializes a {@code ConversionFactorParser} to the given DefaultHandler.

    * 

    * @param newHandler the parser handler that defines how the XML file elements are handled.

    */

   public ConversionFactorParser(final DefaultHandler newHandler)

   {

     handler = newHandler;

     create();

   }

   /**

    * Connects to the XML file and parses it.

    */

   public final void parse()

   {

     try

     {

       final InputStream dataFileStream = getClass().getResourceAsStream(dataFileName);

       saxParser.parse(dataFileStream, handler);

     }

     catch (SAXException e)

     {

       logger.severe(e.getMessage());

     }

     catch (IOException e)

     {

       logger.severe(e.getMessage());

     }

   }

   private void create()

   {

     final SAXParserFactory parserFactory = SAXParserFactory.newInstance();

     try

     {

       saxParser = parserFactory.newSAXParser();

     }

     catch (SAXException e)

     {

       logger.severe(e.getMessage());

     }

     catch (ParserConfigurationException e)

     {

       logger.severe(e.getMessage());

     }

   }

 }