/**
    *    Copyright 2011 meltmedia
    *
    *    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 org.xchain.namespaces.core;
  
  import java.net.URL;
  import java.io.InputStream;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.DocumentBuilder;
  import org.w3c.dom.Document;
  import org.xchain.framework.net.UrlFactory;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * @author Christian Trimble
   * @author Jason Rose
   * @author Josh Kennedy
   */
  public class DocumentFunctions
  {
    public static Logger log = LoggerFactory.getLogger( DocumentFunctions.class );
      public static Document document( String systemId )
      {
        URL url = null;
  
        try {
          url = UrlFactory.getInstance().newUrl(systemId);
        }
        catch( Exception e ) {
          if( log.isDebugEnabled() ) {
            log.debug("Could not create document for system id '"+systemId+".", e);
          }
          throw new RuntimeException("Could not create document.", e);
        }
  
        return document(url);
      }
  
      public static Document document( URL url )
      {
        InputStream documentIn = null;
        try {
        // get the document builder factory.
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  
        // configure the factory to be namespace aware.
        factory.setNamespaceAware( true );
  
        // get the document builder.
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
  
        // create an input stream for the document.
        documentIn = url.openStream();
  
        // build the document.
        Document document = documentBuilder.parse(documentIn);
  
        // return the document.
        return document;
        }
        catch( Exception e ) {
          if( log.isDebugEnabled() ) {
            log.debug("Could not create document for system id '"+url.toExternalForm()+".", e);
          }
          throw new RuntimeException("Could not create document.", e);
  
        }
        finally {
          if( documentIn != null ) {
            try {
              documentIn.close();
            }
            catch( Exception e ) {
              log.warn("Failed to close input stream.", e);
            }
          }
        }
      }
  }