////////////////////////////////////////////////////////////////////////////////

 // checkstyle: Checks Java source code for adherence to a set of rules.

 // Copyright (C) 2001-2014  Oliver Burn

 //

 // This library is free software; you can redistribute it and/or

 // modify it under the terms of the GNU Lesser General Public

 // License as published by the Free Software Foundation; either

 // version 2.1 of the License, or (at your option) any later version.

 //

 // This library is distributed in the hope that it will be useful,

 // but WITHOUT ANY WARRANTY; without even the implied warranty of

 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 // Lesser General Public License for more details.

 //

 // You should have received a copy of the GNU Lesser General Public

 // License along with this library; if not, write to the Free Software

 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 ////////////////////////////////////////////////////////////////////////////////

 package com.puppycrawl.tools.checkstyle.api;

 import com.google.common.collect.Maps;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.HashMap;

 import java.util.Map;

 import javax.xml.parsers.ParserConfigurationException;

 import javax.xml.parsers.SAXParserFactory;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 import org.xml.sax.SAXParseException;

 import org.xml.sax.XMLReader;

 import org.xml.sax.helpers.DefaultHandler;

 /**

  * Contains the common implementation of a loader, for loading a configuration

  * from an XML file.

  * <p>

  * The error handling policy can be described as being austere, dead set,

  * disciplinary, dour, draconian, exacting, firm, forbidding, grim, hard, hard-

  * boiled, harsh, harsh, in line, iron-fisted, no-nonsense, oppressive,

  * persnickety, picky, prudish, punctilious, puritanical, rigid, rigorous,

  * scrupulous, set, severe, square, stern, stickler, straight, strait-laced,

  * stringent, stuffy, stuffy, tough, unpermissive, unsparing and uptight.

  *

  * @author Oliver Burn

  */

 public abstract class AbstractLoader

     extends DefaultHandler

 {

     /** maps public id to resolve to esource name for the DTD */

     private final Map<String, String> mPublicIdToResourceNameMap;

     /** parser to read XML files **/

     private final XMLReader mParser;

     /**

      * Creates a new instance.

      * @param aPublicId the public ID for the DTD to resolve

      * @param aDtdResourceName the resource for the DTD

      * @throws SAXException if an error occurs

      * @throws ParserConfigurationException if an error occurs

      */

     protected AbstractLoader(String aPublicId, String aDtdResourceName)

         throws SAXException, ParserConfigurationException

     {

         this(new HashMap<String, String>(1));

         mPublicIdToResourceNameMap.put(aPublicId, aDtdResourceName);

     }

     /**

      * Creates a new instance.

      * @param aPublicIdToResourceNameMap maps public IDs to DTD resource names

      * @throws SAXException if an error occurs

      * @throws ParserConfigurationException if an error occurs

      */

     protected AbstractLoader(Map<String, String> aPublicIdToResourceNameMap)

         throws SAXException, ParserConfigurationException

     {

         mPublicIdToResourceNameMap =

             Maps.newHashMap(aPublicIdToResourceNameMap);

         final SAXParserFactory factory = SAXParserFactory.newInstance();

         factory.setValidating(true);

         factory.setNamespaceAware(true);

         mParser = factory.newSAXParser().getXMLReader();

         mParser.setContentHandler(this);

         mParser.setEntityResolver(this);

         mParser.setErrorHandler(this);

     }

     /**

      * Parses the specified input source.

      * @param aInputSource the input source to parse.

      * @throws IOException if an error occurs

      * @throws SAXException in an error occurs

      */

     public void parseInputSource(InputSource aInputSource)

         throws IOException, SAXException

     {

         mParser.parse(aInputSource);

     }

     @Override

     public InputSource resolveEntity(String aPublicId, String aSystemId)

         throws SAXException, IOException

     {

         if (mPublicIdToResourceNameMap.keySet().contains(aPublicId)) {

             final String dtdResourceName =

                     mPublicIdToResourceNameMap.get(aPublicId);

             final ClassLoader loader =

                 this.getClass().getClassLoader();

             final InputStream dtdIS =

                 loader.getResourceAsStream(dtdResourceName);

             if (dtdIS == null) {

                 throw new SAXException(

                     "Unable to load internal dtd " + dtdResourceName);

             }

             return new InputSource(dtdIS);

         }

         return super.resolveEntity(aPublicId, aSystemId);

     }

     @Override

     public void warning(SAXParseException aEx) throws SAXException

     {

         throw aEx;

     }

     @Override

     public void error(SAXParseException aEx) throws SAXException

     {

         throw aEx;

     }

     @Override

     public void fatalError(SAXParseException aEx) throws SAXException

     {

         throw aEx;

     }

 }