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 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
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package com.sun.org.apache.xml.internal.serializer;

import com.sun.org.apache.xml.internal.utils.AttList;
import com.sun.org.apache.xml.internal.utils.DOM2Helper;
import javax.xml.transform.Result;
import org.w3c.dom.Comment;
import org.w3c.dom.Element;
import org.w3c.dom.EntityReference;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.ProcessingInstruction;
import org.w3c.dom.Text;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.LocatorImpl;

This class does a pre-order walk of the DOM tree, calling a ContentHandler interface as it goes. This class is a copy of the one in com.sun.org.apache.xml.internal.utils. It exists to cut the serializers dependancy on that package.
@xsl.usageinternal
/** * This class does a pre-order walk of the DOM tree, calling a ContentHandler * interface as it goes. * * This class is a copy of the one in com.sun.org.apache.xml.internal.utils. * It exists to cut the serializers dependancy on that package. * * @xsl.usage internal */
public final class TreeWalker {
Local reference to a ContentHandler
/** Local reference to a ContentHandler */
final private ContentHandler m_contentHandler;
If m_contentHandler is a SerializationHandler, then this is a reference to the same object.
/** * If m_contentHandler is a SerializationHandler, then this is * a reference to the same object. */
final private SerializationHandler m_Serializer;
Locator object for this TreeWalker
/** Locator object for this TreeWalker */
final private LocatorImpl m_locator = new LocatorImpl();
Get the ContentHandler used for the tree walk.
Returns:the ContentHandler used for the tree walk
/** * Get the ContentHandler used for the tree walk. * * @return the ContentHandler used for the tree walk */
public ContentHandler getContentHandler() { return m_contentHandler; } public TreeWalker(ContentHandler ch) { this(ch, null); }
Constructor.
Params:
  • contentHandler – The implemention of the contentHandler operation (toXMLString, digest, ...)
/** * Constructor. * @param contentHandler The implemention of the * contentHandler operation (toXMLString, digest, ...) */
public TreeWalker(ContentHandler contentHandler, String systemId) { // Set the content handler m_contentHandler = contentHandler; if (m_contentHandler instanceof SerializationHandler) { m_Serializer = (SerializationHandler) m_contentHandler; } else { m_Serializer = null; } // Set the system ID, if it is given m_contentHandler.setDocumentLocator(m_locator); if (systemId != null) { m_locator.setSystemId(systemId); } }
Perform a pre-order traversal non-recursive style. Note that TreeWalker assumes that the subtree is intended to represent a complete (though not necessarily well-formed) document and, during a traversal, startDocument and endDocument will always be issued to the SAX listener.
Params:
  • pos – Node in the tree where to start traversal
Throws:
  • TransformerException –
/** * Perform a pre-order traversal non-recursive style. * * Note that TreeWalker assumes that the subtree is intended to represent * a complete (though not necessarily well-formed) document and, during a * traversal, startDocument and endDocument will always be issued to the * SAX listener. * * @param pos Node in the tree where to start traversal * * @throws TransformerException */
public void traverse(Node pos) throws org.xml.sax.SAXException { this.m_contentHandler.startDocument(); Node top = pos; while (null != pos) { startNode(pos); Node nextNode = pos.getFirstChild(); while (null == nextNode) { endNode(pos); if (top.equals(pos)) break; nextNode = pos.getNextSibling(); if (null == nextNode) { pos = pos.getParentNode(); if ((null == pos) || (top.equals(pos))) { if (null != pos) endNode(pos); nextNode = null; break; } } } pos = nextNode; } this.m_contentHandler.endDocument(); }
Perform a pre-order traversal non-recursive style. Note that TreeWalker assumes that the subtree is intended to represent a complete (though not necessarily well-formed) document and, during a traversal, startDocument and endDocument will always be issued to the SAX listener.
Params:
  • pos – Node in the tree where to start traversal
  • top – Node in the tree where to end traversal
Throws:
  • TransformerException –
/** * Perform a pre-order traversal non-recursive style. * Note that TreeWalker assumes that the subtree is intended to represent * a complete (though not necessarily well-formed) document and, during a * traversal, startDocument and endDocument will always be issued to the * SAX listener. * * @param pos Node in the tree where to start traversal * @param top Node in the tree where to end traversal * * @throws TransformerException */
public void traverse(Node pos, Node top) throws org.xml.sax.SAXException { this.m_contentHandler.startDocument(); while (null != pos) { startNode(pos); Node nextNode = pos.getFirstChild(); while (null == nextNode) { endNode(pos); if ((null != top) && top.equals(pos)) break; nextNode = pos.getNextSibling(); if (null == nextNode) { pos = pos.getParentNode(); if ((null == pos) || ((null != top) && top.equals(pos))) { nextNode = null; break; } } } pos = nextNode; } this.m_contentHandler.endDocument(); } // Flag indicating whether following text to be processed is raw text boolean nextIsRaw = false;
Optimized dispatch of characters.
/** * Optimized dispatch of characters. */
private final void dispatachChars(Node node) throws org.xml.sax.SAXException { if(m_Serializer != null) { this.m_Serializer.characters(node); } else { String data = ((Text) node).getData(); this.m_contentHandler.characters(data.toCharArray(), 0, data.length()); } }
Start processing given node
Params:
  • node – Node to process
Throws:
/** * Start processing given node * * * @param node Node to process * * @throws org.xml.sax.SAXException */
protected void startNode(Node node) throws org.xml.sax.SAXException { // TODO: <REVIEW> // A Serializer implements ContentHandler, but not NodeConsumer // so drop this reference to NodeConsumer which would otherwise // pull in all sorts of things // if (m_contentHandler instanceof NodeConsumer) // { // ((NodeConsumer) m_contentHandler).setOriginatingNode(node); // } // TODO: </REVIEW> if (node instanceof Locator) { Locator loc = (Locator)node; m_locator.setColumnNumber(loc.getColumnNumber()); m_locator.setLineNumber(loc.getLineNumber()); m_locator.setPublicId(loc.getPublicId()); m_locator.setSystemId(loc.getSystemId()); } else { m_locator.setColumnNumber(0); m_locator.setLineNumber(0); } switch (node.getNodeType()) { case Node.COMMENT_NODE : { String data = ((Comment) node).getData(); if (m_contentHandler instanceof LexicalHandler) { LexicalHandler lh = ((LexicalHandler) this.m_contentHandler); lh.comment(data.toCharArray(), 0, data.length()); } } break; case Node.DOCUMENT_FRAGMENT_NODE : // ??; break; case Node.DOCUMENT_NODE : break; case Node.ELEMENT_NODE : Element elem_node = (Element) node; { // Make sure the namespace node // for the element itself is declared // to the ContentHandler String uri = elem_node.getNamespaceURI(); if (uri != null) { String prefix = elem_node.getPrefix(); if (prefix==null) prefix=""; this.m_contentHandler.startPrefixMapping(prefix,uri); } } NamedNodeMap atts = elem_node.getAttributes(); int nAttrs = atts.getLength(); // System.out.println("TreeWalker#startNode: "+node.getNodeName()); // Make sure the namespace node of // each attribute is declared to the ContentHandler for (int i = 0; i < nAttrs; i++) { final Node attr = atts.item(i); final String attrName = attr.getNodeName(); final int colon = attrName.indexOf(':'); final String prefix; if (attrName.equals("xmlns") || attrName.startsWith("xmlns:")) { // Use "" instead of null, as Xerces likes "" for the // name of the default namespace. Fix attributed // to "Steven Murray" <smurray@ebt.com>. if (colon < 0) prefix = ""; else prefix = attrName.substring(colon + 1); this.m_contentHandler.startPrefixMapping(prefix, attr.getNodeValue()); } else if (colon > 0) { prefix = attrName.substring(0,colon); String uri = attr.getNamespaceURI(); if (uri != null) this.m_contentHandler.startPrefixMapping(prefix,uri); } } String ns = DOM2Helper.getNamespaceOfNode(node); if(null == ns) ns = ""; this.m_contentHandler.startElement(ns, DOM2Helper.getLocalNameOfNode(node), node.getNodeName(), new AttList(atts)); break; case Node.PROCESSING_INSTRUCTION_NODE : { ProcessingInstruction pi = (ProcessingInstruction) node; String name = pi.getNodeName(); // String data = pi.getData(); if (name.equals("xslt-next-is-raw")) { nextIsRaw = true; } else { this.m_contentHandler.processingInstruction(pi.getNodeName(), pi.getData()); } } break; case Node.CDATA_SECTION_NODE : { boolean isLexH = (m_contentHandler instanceof LexicalHandler); LexicalHandler lh = isLexH ? ((LexicalHandler) this.m_contentHandler) : null; if (isLexH) { lh.startCDATA(); } dispatachChars(node); { if (isLexH) { lh.endCDATA(); } } } break; case Node.TEXT_NODE : { //String data = ((Text) node).getData(); if (nextIsRaw) { nextIsRaw = false; m_contentHandler.processingInstruction(Result.PI_DISABLE_OUTPUT_ESCAPING, ""); dispatachChars(node); m_contentHandler.processingInstruction(Result.PI_ENABLE_OUTPUT_ESCAPING, ""); } else { dispatachChars(node); } } break; case Node.ENTITY_REFERENCE_NODE : { EntityReference eref = (EntityReference) node; if (m_contentHandler instanceof LexicalHandler) { ((LexicalHandler) this.m_contentHandler).startEntity( eref.getNodeName()); } else { // warning("Can not output entity to a pure SAX ContentHandler"); } } break; default : } }
End processing of given node
Params:
  • node – Node we just finished processing
Throws:
/** * End processing of given node * * * @param node Node we just finished processing * * @throws org.xml.sax.SAXException */
protected void endNode(Node node) throws org.xml.sax.SAXException { switch (node.getNodeType()) { case Node.DOCUMENT_NODE : break; case Node.ELEMENT_NODE : String ns = DOM2Helper.getNamespaceOfNode(node); if(null == ns) ns = ""; this.m_contentHandler.endElement(ns, DOM2Helper.getLocalNameOfNode(node), node.getNodeName()); if (m_Serializer == null) { // Don't bother with endPrefixMapping calls if the ContentHandler is a // SerializationHandler because SerializationHandler's ignore the // endPrefixMapping() calls anyways. . . . This is an optimization. Element elem_node = (Element) node; NamedNodeMap atts = elem_node.getAttributes(); int nAttrs = atts.getLength(); // do the endPrefixMapping calls in reverse order // of the startPrefixMapping calls for (int i = (nAttrs-1); 0 <= i; i--) { final Node attr = atts.item(i); final String attrName = attr.getNodeName(); final int colon = attrName.indexOf(':'); final String prefix; if (attrName.equals("xmlns") || attrName.startsWith("xmlns:")) { // Use "" instead of null, as Xerces likes "" for the // name of the default namespace. Fix attributed // to "Steven Murray" <smurray@ebt.com>. if (colon < 0) prefix = ""; else prefix = attrName.substring(colon + 1); this.m_contentHandler.endPrefixMapping(prefix); } else if (colon > 0) { prefix = attrName.substring(0, colon); this.m_contentHandler.endPrefixMapping(prefix); } } { String uri = elem_node.getNamespaceURI(); if (uri != null) { String prefix = elem_node.getPrefix(); if (prefix==null) prefix=""; this.m_contentHandler.endPrefixMapping(prefix); } } } break; case Node.CDATA_SECTION_NODE : break; case Node.ENTITY_REFERENCE_NODE : { EntityReference eref = (EntityReference) node; if (m_contentHandler instanceof LexicalHandler) { LexicalHandler lh = ((LexicalHandler) this.m_contentHandler); lh.endEntity(eref.getNodeName()); } } break; default : } } } //TreeWalker