/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This 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 software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
//$Id: HibernateEntityResolver.java 5332 2006-04-29 18:32:44Z geaz $
//Contributed by Markus Meissner
package org.etk.component.database.impl;

import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.Serializable;

public class HibernateEntityResolver implements EntityResolver, Serializable
{

   private static final String URL = "http://hibernate.sourceforge.net/";

   private transient ClassLoader resourceLoader;

   /**
    * Default constructor using DTDEntityResolver classloader for resource
    * loading.
    */
   public HibernateEntityResolver()
   {
      // backward compatibility
      resourceLoader = this.getClass().getClassLoader();
   }

   /**
    * Set the class loader used to load resouces
    * 
    * @param resourceLoader class loader to use
    */
   public HibernateEntityResolver(ClassLoader resourceLoader)
   {
      this.resourceLoader = resourceLoader;
   }

   public InputSource resolveEntity(String publicId, String systemId)
   {
      // S ystem.out.println("====> Resolve entity, public id " + publicId +
      // " system id " + systemId) ;
      if (systemId != null && systemId.startsWith(URL))
      {
         // S ystem.out.println("trying to locate " + systemId +
         // " in classpath under org/hibernate/");
         // Search for DTD
         InputStream dtdStream =
            resourceLoader.getResourceAsStream("org/hibernate/" + systemId.substring(URL.length()));
         if (dtdStream == null)
            return null;
         // S ystem.out.println("found " + systemId + " in classpath");
         InputSource source = new InputSource(dtdStream);
         source.setPublicId(publicId);
         source.setSystemId(systemId);
         return source;
      }
      // use the default behaviour
      return null;
   }

   private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException
   {
      /** to allow serialization of configuration */
      ois.defaultReadObject();
      this.resourceLoader = this.getClass().getClassLoader();
   }
}