1 /*
   2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.bind.unmarshaller;
  27 
  28 import java.util.Enumeration;
  29 
  30 import javax.xml.bind.ValidationEventLocator;
  31 import javax.xml.bind.helpers.AbstractUnmarshallerImpl;
  32 import javax.xml.bind.helpers.ValidationEventLocatorImpl;
  33 
  34 import com.sun.xml.internal.bind.v2.runtime.unmarshaller.LocatorEx;
  35 
  36 import org.w3c.dom.Attr;
  37 import org.w3c.dom.Document;
  38 import org.w3c.dom.Element;
  39 import org.w3c.dom.NamedNodeMap;
  40 import org.w3c.dom.Node;
  41 import org.w3c.dom.NodeList;
  42 import org.w3c.dom.ProcessingInstruction;
  43 import org.xml.sax.ContentHandler;
  44 import org.xml.sax.Locator;
  45 import org.xml.sax.SAXException;
  46 import org.xml.sax.helpers.AttributesImpl;
  47 import org.xml.sax.helpers.NamespaceSupport;
  48 
  49 /**
  50  * Visits a W3C DOM tree and generates SAX2 events from it.
  51  *
  52  * <p>
  53  * This class is just intended to be used by {@link AbstractUnmarshallerImpl}.
  54  * The javax.xml.bind.helpers package is generally a wrong place to put
  55  * classes like this.
  56  *
  57  * @author <ul><li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li></ul>
  58  * @since JAXB 1.0
  59  */
  60 public class DOMScanner implements LocatorEx,InfosetScanner/*<Node> --- but can't do this to protect 1.0 clients, or can I? */
  61 {
  62 
  63     /** reference to the current node being scanned - used for determining
  64      *  location info for validation events */
  65     private Node currentNode = null;
  66 
  67     /** To save memory, only one instance of AttributesImpl will be used. */
  68     private final AttributesImpl atts = new AttributesImpl();
  69 
  70     /** This handler will receive SAX2 events. */
  71     private ContentHandler receiver=null;
  72 
  73     private Locator locator=this;
  74 
  75     public DOMScanner() {
  76     }
  77 
  78 
  79     /**
  80      * Configures the locator object that the SAX {@link ContentHandler} will see.
  81      */
  82     public void setLocator( Locator loc ) {
  83         this.locator = loc;
  84     }
  85 
  86     public void scan(Object node) throws SAXException {
  87         if( node instanceof Document ) {
  88             scan( (Document)node );
  89         } else {
  90             scan( (Element)node );
  91         }
  92     }
  93 
  94     public void scan( Document doc ) throws SAXException {
  95         scan( doc.getDocumentElement() );
  96     }
  97 
  98     public void scan( Element e) throws SAXException {
  99         setCurrentLocation( e );
 100 
 101         receiver.setDocumentLocator(locator);
 102         receiver.startDocument();
 103 
 104         NamespaceSupport nss = new NamespaceSupport();
 105         buildNamespaceSupport( nss, e.getParentNode() );
 106 
 107         for( Enumeration en = nss.getPrefixes(); en.hasMoreElements(); ) {
 108             String prefix = (String)en.nextElement();
 109             receiver.startPrefixMapping( prefix, nss.getURI(prefix) );
 110         }
 111 
 112         visit(e);
 113 
 114         for( Enumeration en = nss.getPrefixes(); en.hasMoreElements(); ) {
 115             String prefix = (String)en.nextElement();
 116             receiver.endPrefixMapping( prefix );
 117         }
 118 
 119 
 120         setCurrentLocation( e );
 121         receiver.endDocument();
 122     }
 123 
 124     /**
 125      * Parses a subtree starting from the element e and
 126      * reports SAX2 events to the specified handler.
 127      *
 128      * @deprecated in JAXB 2.0
 129      *      Use {@link #scan(Element)}
 130      */
 131     public void parse( Element e, ContentHandler handler ) throws SAXException {
 132         // it might be better to set receiver at the constructor.
 133         receiver = handler;
 134 
 135         setCurrentLocation( e );
 136         receiver.startDocument();
 137 
 138         receiver.setDocumentLocator(locator);
 139         visit(e);
 140 
 141         setCurrentLocation( e );
 142         receiver.endDocument();
 143     }
 144 
 145     /**
 146      * Similar to the parse method but it visits the ancestor nodes
 147      * and properly emulate the all in-scope namespace declarations.
 148      *
 149      * @deprecated in JAXB 2.0
 150      *      Use {@link #scan(Element)}
 151      */
 152     public void parseWithContext( Element e, ContentHandler handler ) throws SAXException {
 153         setContentHandler(handler);
 154         scan(e);
 155     }
 156 
 157     /**
 158      * Recursively visit ancestors and build up {@link NamespaceSupport} oject.
 159      */
 160     private void buildNamespaceSupport(NamespaceSupport nss, Node node) {
 161         if(node==null || node.getNodeType()!=Node.ELEMENT_NODE)
 162             return;
 163 
 164         buildNamespaceSupport( nss, node.getParentNode() );
 165 
 166         nss.pushContext();
 167         NamedNodeMap atts = node.getAttributes();
 168         for( int i=0; i<atts.getLength(); i++ ) {
 169             Attr a = (Attr)atts.item(i);
 170             if( "xmlns".equals(a.getPrefix()) ) {
 171                 nss.declarePrefix( a.getLocalName(), a.getValue() );
 172                 continue;
 173             }
 174             if( "xmlns".equals(a.getName()) ) {
 175                 nss.declarePrefix( "", a.getValue() );
 176                 continue;
 177             }
 178         }
 179     }
 180 
 181     /**
 182      * Visits an element and its subtree.
 183      */
 184     public void visit( Element e ) throws SAXException {
 185         setCurrentLocation( e );
 186         final NamedNodeMap attributes = e.getAttributes();
 187 
 188         atts.clear();
 189         int len = attributes==null ? 0: attributes.getLength();
 190 
 191         for( int i=len-1; i>=0; i-- ) {
 192             Attr a = (Attr)attributes.item(i);
 193             String name = a.getName();
 194             // start namespace binding
 195            if(name.startsWith("xmlns")) {
 196                 if(name.length()==5) {
 197                     receiver.startPrefixMapping( "", a.getValue() );
 198                 } else {
 199                     String localName = a.getLocalName();
 200                     if(localName==null) {
 201                         // DOM built without namespace support has this problem
 202                         localName = name.substring(6);
 203                     }
 204                     receiver.startPrefixMapping( localName, a.getValue() );
 205                 }
 206                 continue;
 207             }
 208 
 209             String uri = a.getNamespaceURI();
 210             if(uri==null)   uri="";
 211 
 212             String local = a.getLocalName();
 213             if(local==null) local = a.getName();
 214             // add other attributes to the attribute list
 215             // that we will pass to the ContentHandler
 216             atts.addAttribute(
 217                 uri,
 218                 local,
 219                 a.getName(),
 220                 "CDATA",
 221                 a.getValue());
 222         }
 223 
 224         String uri = e.getNamespaceURI();
 225         if(uri==null)   uri="";
 226         String local = e.getLocalName();
 227         String qname = e.getTagName();
 228         if(local==null) local = qname;
 229         receiver.startElement( uri, local, qname, atts );
 230 
 231         // visit its children
 232         NodeList children = e.getChildNodes();
 233         int clen = children.getLength();
 234         for( int i=0; i<clen; i++ )
 235             visit(children.item(i));
 236 
 237 
 238 
 239         setCurrentLocation( e );
 240         receiver.endElement( uri, local, qname );
 241 
 242         // call the endPrefixMapping method
 243         for( int i=len-1; i>=0; i-- ) {
 244             Attr a = (Attr)attributes.item(i);
 245             String name = a.getName();
 246             if(name.startsWith("xmlns")) {
 247                 if(name.length()==5)
 248                     receiver.endPrefixMapping("");
 249                 else
 250                     receiver.endPrefixMapping(a.getLocalName());
 251             }
 252         }
 253     }
 254 
 255     private void visit( Node n ) throws SAXException {
 256         setCurrentLocation( n );
 257 
 258         // if a case statement gets too big, it should be made into a separate method.
 259         switch(n.getNodeType()) {
 260         case Node.CDATA_SECTION_NODE:
 261         case Node.TEXT_NODE:
 262             String value = n.getNodeValue();
 263             receiver.characters( value.toCharArray(), 0, value.length() );
 264             break;
 265         case Node.ELEMENT_NODE:
 266             visit( (Element)n );
 267             break;
 268         case Node.ENTITY_REFERENCE_NODE:
 269             receiver.skippedEntity(n.getNodeName());
 270             break;
 271         case Node.PROCESSING_INSTRUCTION_NODE:
 272             ProcessingInstruction pi = (ProcessingInstruction)n;
 273             receiver.processingInstruction(pi.getTarget(),pi.getData());
 274             break;
 275         }
 276     }
 277 
 278     private void setCurrentLocation( Node currNode ) {
 279         currentNode = currNode;
 280     }
 281 
 282     /**
 283      * The same as {@link #getCurrentElement()} but
 284      * better typed.
 285      */
 286     public Node getCurrentLocation() {
 287         return currentNode;
 288     }
 289 
 290     public Object getCurrentElement() {
 291         return currentNode;
 292     }
 293 
 294     public LocatorEx getLocator() {
 295         return this;
 296     }
 297 
 298     public void setContentHandler(ContentHandler handler) {
 299         this.receiver = handler;
 300     }
 301 
 302     public ContentHandler getContentHandler() {
 303         return this.receiver;
 304     }
 305 
 306 
 307     // LocatorEx implementation
 308     public String getPublicId() { return null; }
 309     public String getSystemId() { return null; }
 310     public int getLineNumber() { return -1; }
 311     public int getColumnNumber() { return -1; }
 312 
 313     public ValidationEventLocator getLocation() {
 314         return new ValidationEventLocatorImpl(getCurrentLocation());
 315     }
 316 }