dombuilder.java

来自「JAVA 所有包」· Java 代码 · 共 787 行 · 第 1/2 页

/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * 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.
 */
/*
 * $Id: DOMBuilder.java,v 1.2.4.1 2005/09/15 08:15:39 suresh_emailid Exp $
 */
package com.sun.org.apache.xml.internal.utils;

import java.util.Stack;

import com.sun.org.apache.xml.internal.res.XMLErrorResources;
import com.sun.org.apache.xml.internal.res.XMLMessages;

import org.w3c.dom.Document;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import org.w3c.dom.CDATASection;

import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.ext.LexicalHandler;
/**
 * This class takes SAX events (in addition to some extra events
 * that SAX doesn't handle yet) and adds the result to a document
 * or document fragment.
 * @xsl.usage general
 */
public class DOMBuilder
        implements ContentHandler, LexicalHandler
{

  /** Root document          */
  public Document m_doc;

  /** Current node           */
  protected Node m_currentNode = null;
  
  /** The root node          */
  protected Node m_root = null;
  
  /** The next sibling node  */
  protected Node m_nextSibling = null;

  /** First node of document fragment or null if not a DocumentFragment     */
  public DocumentFragment m_docFrag = null;

  /** Vector of element nodes          */
  protected Stack m_elemStack = new Stack();

  /**
   * DOMBuilder instance constructor... it will add the DOM nodes
   * to the document fragment.
   *
   * @param doc Root document
   * @param node Current node
   */
  public DOMBuilder(Document doc, Node node)
  {
    m_doc = doc;
    m_currentNode = m_root = node;
    
    if (node instanceof Element)
      m_elemStack.push(node);
  }

  /**
   * DOMBuilder instance constructor... it will add the DOM nodes
   * to the document fragment.
   *
   * @param doc Root document
   * @param docFrag Document fragment
   */
  public DOMBuilder(Document doc, DocumentFragment docFrag)
  {
    m_doc = doc;
    m_docFrag = docFrag;
  }

  /**
   * DOMBuilder instance constructor... it will add the DOM nodes
   * to the document.
   *
   * @param doc Root document
   */
  public DOMBuilder(Document doc)
  {
    m_doc = doc;
  }

  /**
   * Get the root document or DocumentFragment of the DOM being created.
   *
   * @return The root document or document fragment if not null
   */
  public Node getRootDocument()
  {
    return (null != m_docFrag) ? (Node) m_docFrag : (Node) m_doc;
  }
  
  /**
   * Get the root node of the DOM tree.
   */
  public Node getRootNode()
  {
    return m_root;
  }
  
  /**
   * Get the node currently being processed.
   *
   * @return the current node being processed
   */
  public Node getCurrentNode()
  {
    return m_currentNode;
  }
  
  /**
   * Set the next sibling node, which is where the result nodes 
   * should be inserted before.
   * 
   * @param nextSibling the next sibling node.
   */
  public void setNextSibling(Node nextSibling)
  {
    m_nextSibling = nextSibling;
  }
  
  /**
   * Return the next sibling node.
   * 
   * @return the next sibling node.
   */
  public Node getNextSibling()
  {
    return m_nextSibling;
  }

  /**
   * Return null since there is no Writer for this class.
   *
   * @return null
   */
  public java.io.Writer getWriter()
  {
    return null;
  }

  /**
   * Append a node to the current container.
   *
   * @param newNode New node to append
   */
  protected void append(Node newNode) throws org.xml.sax.SAXException
  {

    Node currentNode = m_currentNode;

    if (null != currentNode)
    {
      if (currentNode == m_root && m_nextSibling != null)
        currentNode.insertBefore(newNode, m_nextSibling);
      else
        currentNode.appendChild(newNode);

      // System.out.println(newNode.getNodeName());
    }
    else if (null != m_docFrag)
    {
      if (m_nextSibling != null)
        m_docFrag.insertBefore(newNode, m_nextSibling);
      else
        m_docFrag.appendChild(newNode);
    }
    else
    {
      boolean ok = true;
      short type = newNode.getNodeType();

      if (type == Node.TEXT_NODE)
      {
        String data = newNode.getNodeValue();

        if ((null != data) && (data.trim().length() > 0))
        {
          throw new org.xml.sax.SAXException(
            XMLMessages.createXMLMessage(
              XMLErrorResources.ER_CANT_OUTPUT_TEXT_BEFORE_DOC, null));  //"Warning: can't output text before document element!  Ignoring...");
        }

        ok = false;
      }
      else if (type == Node.ELEMENT_NODE)
      {
        if (m_doc.getDocumentElement() != null)
        {
          ok = false;
          
          throw new org.xml.sax.SAXException(
            XMLMessages.createXMLMessage(
              XMLErrorResources.ER_CANT_HAVE_MORE_THAN_ONE_ROOT, null));  //"Can't have more than one root on a DOM!");
        }
      }

      if (ok)
      {
        if (m_nextSibling != null)
          m_doc.insertBefore(newNode, m_nextSibling);
        else
          m_doc.appendChild(newNode);
      }
    }
  }

  /**
   * Receive an object for locating the origin of SAX document events.
   *
   * <p>SAX parsers are strongly encouraged (though not absolutely
   * required) to supply a locator: if it does so, it must supply
   * the locator to the application by invoking this method before
   * invoking any of the other methods in the ContentHandler
   * interface.</p>
   *
   * <p>The locator allows the application to determine the end
   * position of any document-related event, even if the parser is
   * not reporting an error.  Typically, the application will
   * use this information for reporting its own errors (such as
   * character content that does not match an application's
   * business rules).  The information returned by the locator
   * is probably not sufficient for use with a search engine.</p>
   *
   * <p>Note that the locator will return correct information only
   * during the invocation of the events in this interface.  The
   * application should not attempt to use it at any other time.</p>
   *
   * @param locator An object that can return the location of
   *                any SAX document event.
   * @see org.xml.sax.Locator
   */
  public void setDocumentLocator(Locator locator)
  {

    // No action for the moment.
  }

  /**
   * Receive notification of the beginning of a document.
   *
   * <p>The SAX parser will invoke this method only once, before any
   * other methods in this interface or in DTDHandler (except for
   * setDocumentLocator).</p>
   */
  public void startDocument() throws org.xml.sax.SAXException
  {

    // No action for the moment.
  }

  /**
   * Receive notification of the end of a document.
   *
   * <p>The SAX parser will invoke this method only once, and it will
   * be the last method invoked during the parse.  The parser shall
   * not invoke this method until it has either abandoned parsing
   * (because of an unrecoverable error) or reached the end of
   * input.</p>
   */
  public void endDocument() throws org.xml.sax.SAXException
  {

    // No action for the moment.
  }

  /**
   * Receive notification of the beginning of an element.
   *
   * <p>The Parser will invoke this method at the beginning of every
   * element in the XML document; there will be a corresponding
   * endElement() event for every startElement() event (even when the
   * element is empty). All of the element's content will be
   * reported, in order, before the corresponding endElement()
   * event.</p>
   *
   * <p>If the element name has a namespace prefix, the prefix will
   * still be attached.  Note that the attribute list provided will
   * contain only attributes with explicit values (specified or
   * defaulted): #IMPLIED attributes will be omitted.</p>
   *
   *
   * @param ns The namespace of the node
   * @param localName The local part of the qualified name
   * @param name The element name.
   * @param atts The attributes attached to the element, if any.
   * @see #endElement
   * @see org.xml.sax.Attributes
   */
  public void startElement(
          String ns, String localName, String name, Attributes atts)
            throws org.xml.sax.SAXException
  {

    Element elem;

	// Note that the namespace-aware call must be used to correctly
	// construct a Level 2 DOM, even for non-namespaced nodes.
    if ((null == ns) || (ns.length() == 0))
      elem = m_doc.createElementNS(null,name);
    else
      elem = m_doc.createElementNS(ns, name);

    append(elem);

    try
    {
      int nAtts = atts.getLength();

      if (0 != nAtts)
      {
        for (int i = 0; i < nAtts; i++)
        {

          //System.out.println("type " + atts.getType(i) + " name " + atts.getLocalName(i) );
          // First handle a possible ID attribute
          if (atts.getType(i).equalsIgnoreCase("ID"))
            setIDAttribute(atts.getValue(i), elem);

          String attrNS = atts.getURI(i);

          if("".equals(attrNS))
            attrNS = null; // DOM represents no-namespace as null

          // System.out.println("attrNS: "+attrNS+", localName: "+atts.getQName(i)
          //                   +", qname: "+atts.getQName(i)+", value: "+atts.getValue(i));
          // Crimson won't let us set an xmlns: attribute on the DOM.
          String attrQName = atts.getQName(i);

          // In SAX, xmlns[:] attributes have an empty namespace, while in DOM they 
          // should have the xmlns namespace
          if (attrQName.startsWith("xmlns:") || attrQName.equals("xmlns")) {
            attrNS = "http://www.w3.org/2000/xmlns/";
          }

          // ALWAYS use the DOM Level 2 call!
          elem.setAttributeNS(attrNS,attrQName, atts.getValue(i));
        }
      }

      // append(elem);

      m_elemStack.push(elem);

      m_currentNode = elem;

      // append(elem);
    }
    catch(java.lang.Exception de)
    {
      // de.printStackTrace();
      throw new org.xml.sax.SAXException(de);
    }

  }

  /**



   * Receive notification of the end of an element.
   *
   * <p>The SAX parser will invoke this method at the end of every
   * element in the XML document; there will be a corresponding
   * startElement() event for every endElement() event (even when the
   * element is empty).</p>
   *
   * <p>If the element name has a namespace prefix, the prefix will
   * still be attached to the name.</p>
   *
   *
   * @param ns the namespace of the element