transformeridentityimpl.java

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/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xalan.transformer;

import java.util.Properties;
import java.util.Hashtable;

import java.io.IOException;

// TRaX Imports
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.sax.*;
import javax.xml.transform.stream.*;
import javax.xml.parsers.*;

import org.xml.sax.*;
import org.xml.sax.helpers.*;
import org.xml.sax.ext.*;

import org.apache.xalan.serialize.*;
import org.apache.xml.utils.DOMBuilder;
import org.apache.xml.utils.TreeWalker;
import org.apache.xalan.templates.OutputProperties;
import org.apache.xalan.serialize.Method;
import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xalan.res.XSLMessages;

import org.w3c.dom.*;

/**
 * This class implements an identity transformer for
 * {@link javax.xml.transform.sax.SAXTransformerFactory#newTransformerHandler()
 * and {@link javax.xml.transform.TransformerFactory#newTransformer()}.  It
 * simply feeds SAX events directly to a serializer ContentHandler, if the
 * result is a stream.  If the result is a DOM, it will send the events to
 * {@link org.apache.xml.utils.DOMBuilder}.  If the result is another
 * content handler, it will simply pass the events on.
 */
public class TransformerIdentityImpl extends Transformer
        implements TransformerHandler, DeclHandler
{

  /**
   * Constructor TransformerIdentityImpl creates an identity transform.
   *
   */
  public TransformerIdentityImpl()
  {
    m_outputFormat = new OutputProperties(Method.XML);
  }

  /**
   * Enables the user of the TransformerHandler to set the
   * to set the Result for the transformation.
   *
   * @param result A Result instance, should not be null.
   *
   * @throws IllegalArgumentException if result is invalid for some reason.
   */
  public void setResult(Result result) throws IllegalArgumentException
  {
    if(null == result)
      throw new IllegalArgumentException(XSLMessages.createMessage(XSLTErrorResources.ER_RESULT_NULL, null)); //"Result should not be null");        
    m_result = result;
  }

  /**
   * Set the base ID (URI or system ID) from where relative
   * URLs will be resolved.
   * @param systemID Base URI for the source tree.
   */
  public void setSystemId(String systemID)
  {
    m_systemID = systemID;
  }

  /**
   * Get the base ID (URI or system ID) from where relative
   * URLs will be resolved.
   * @return The systemID that was set with {@link #setSystemId}.
   */
  public String getSystemId()
  {
    return m_systemID;
  }

  /**
   * Get the Transformer associated with this handler, which
   * is needed in order to set parameters and output properties.
   *
   * @return non-null reference to the transformer.
   */
  public Transformer getTransformer()
  {
    return this;
  }

  /**
   * Create a result ContentHandler from a Result object, based
   * on the current OutputProperties.
   *
   * @param outputTarget Where the transform result should go,
   * should not be null.
   *
   * @return A valid ContentHandler that will create the
   * result tree when it is fed SAX events.
   *
   * @throws TransformerException
   */
  private void createResultContentHandler(Result outputTarget)
          throws TransformerException
  {

    if (outputTarget instanceof SAXResult)
    {
      SAXResult saxResult = (SAXResult) outputTarget;

      m_resultContentHandler = saxResult.getHandler();
      m_resultLexicalHandler = saxResult.getLexicalHandler();

      if (m_resultContentHandler instanceof Serializer)
      {

        // Dubious but needed, I think.
        m_serializer = (Serializer) m_resultContentHandler;
      }
    }
    else if (outputTarget instanceof DOMResult)
    {
      DOMResult domResult = (DOMResult) outputTarget;
      Node outputNode = domResult.getNode();
      Document doc;
      short type;

      if (null != outputNode)
      {
        type = outputNode.getNodeType();
        doc = (Node.DOCUMENT_NODE == type)
              ? (Document) outputNode : outputNode.getOwnerDocument();
      }
      else
      {
        try
        {
          DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

          dbf.setNamespaceAware(true);

          DocumentBuilder db = dbf.newDocumentBuilder();

          doc = db.newDocument();
        }
        catch (ParserConfigurationException pce)
        {
          throw new TransformerException(pce);
        }

        outputNode = doc;
        type = outputNode.getNodeType();

        ((DOMResult) outputTarget).setNode(outputNode);
      }

      m_resultContentHandler =
        (Node.DOCUMENT_FRAGMENT_NODE == type)
        ? new DOMBuilder(doc, (DocumentFragment) outputNode)
        : new DOMBuilder(doc, outputNode);
      m_resultLexicalHandler = (LexicalHandler) m_resultContentHandler;
    }
    else if (outputTarget instanceof StreamResult)
    {
      StreamResult sresult = (StreamResult) outputTarget;
      String method = m_outputFormat.getProperty(OutputKeys.METHOD);

      try
      {
        Serializer serializer =
          SerializerFactory.getSerializer(m_outputFormat.getProperties());

        m_serializer = serializer;

        if (null != sresult.getWriter())
          serializer.setWriter(sresult.getWriter());
        else if (null != sresult.getOutputStream())
          serializer.setOutputStream(sresult.getOutputStream());
        else if (null != sresult.getSystemId())
        {
          String fileURL = sresult.getSystemId();

          if (fileURL.startsWith("file:///"))
          {
            if (fileURL.substring(8).indexOf(":") >0)
              fileURL = fileURL.substring(8);
            else 
              fileURL = fileURL.substring(7);
          }

          m_outputStream = new java.io.FileOutputStream(fileURL);
          serializer.setOutputStream(m_outputStream);
        }
        else
          throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_NO_OUTPUT_SPECIFIED, null)); //"No output specified!");

        m_resultContentHandler = serializer.asContentHandler();
      }
      catch (IOException ioe)
      {
        throw new TransformerException(ioe);
      }
    }
    else
    {
      throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_CANNOT_TRANSFORM_TO_RESULT_TYPE, new Object[]{outputTarget.getClass().getName()})); //"Can't transform to a Result of type "
                                    // + outputTarget.getClass().getName()
                                    // + "!");
    }

    if (m_resultContentHandler instanceof DTDHandler)
      m_resultDTDHandler = (DTDHandler) m_resultContentHandler;
    
    if (m_resultContentHandler instanceof DeclHandler)
      m_resultDeclHandler = (DeclHandler) m_resultContentHandler;

    if (m_resultContentHandler instanceof LexicalHandler)
      m_resultLexicalHandler = (LexicalHandler) m_resultContentHandler;
  }

  /**
   * Process the source tree to the output result.
   * @param source  The input for the source tree.
   *
   * @param outputTarget The output target.
   *
   * @throws TransformerException If an unrecoverable error occurs
   * during the course of the transformation.
   */
  public void transform(Source source, Result outputTarget)
          throws TransformerException
  {

    createResultContentHandler(outputTarget);

    try
    {
      if (source instanceof DOMSource)
      {
        DOMSource dsource = (DOMSource) source;
  
        m_systemID = dsource.getSystemId();
  
        Node dNode = dsource.getNode();
  
        if (null != dNode)
        {
          try
          {
            if(dNode.getNodeType() != Node.DOCUMENT_NODE)
              this.startDocument();
            try
            {
              if(dNode.getNodeType() == Node.ATTRIBUTE_NODE)
              {
                String data = dNode.getNodeValue();
                char[] chars = data.toCharArray();
                characters(chars, 0, chars.length);
              }
              else
              {
                TreeWalker walker = new TreeWalker(this, new org.apache.xpath.DOM2Helper(), m_systemID);
                walker.traverse(dNode);
              }
            }
            finally
            {
              if(dNode.getNodeType() != Node.DOCUMENT_NODE)
                this.endDocument();
            }
          }
          catch (SAXException se)
          {
            throw new TransformerException(se);
          }
  
          return;
        }
        else
        {
          String messageStr = XSLMessages.createMessage(
            XSLTErrorResources.ER_ILLEGAL_DOMSOURCE_INPUT, null);
  
          throw new IllegalArgumentException(messageStr);
        }
      }
  
      InputSource xmlSource = SAXSource.sourceToInputSource(source);
  
      if (null == xmlSource)
      {
        throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_CANNOT_TRANSFORM_SOURCE_TYPE, new Object[]{source.getClass().getName()})); //"Can't transform a Source of type "
                                       //+ source.getClass().getName() + "!");
      }