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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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package com.sun.xml.internal.bind.unmarshaller;

import java.util.Enumeration;

import javax.xml.bind.ValidationEventLocator;

import javax.xml.bind.helpers.AbstractUnmarshallerImpl;

import javax.xml.bind.helpers.ValidationEventLocatorImpl;

import com.sun.xml.internal.bind.v2.runtime.unmarshaller.LocatorEx;

import org.w3c.dom.Attr;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

import org.w3c.dom.ProcessingInstruction;

import org.xml.sax.ContentHandler;

import org.xml.sax.Locator;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.AttributesImpl;

import org.xml.sax.helpers.NamespaceSupport;

/**

 * Visits a W3C DOM tree and generates SAX2 events from it.

 *

 * <p>

 * This class is just intended to be used by {@link AbstractUnmarshallerImpl}.

 * The javax.xml.bind.helpers package is generally a wrong place to put

 * classes like this.

 *

 * @author <ul><li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li></ul>

 * @since JAXB1.0

 */

public class DOMScanner implements LocatorEx,InfosetScanner/*<Node> --- but can't do this to protect 1.0 clients, or can I? */

{

    /** reference to the current node being scanned - used for determining

     *  location info for validation events */

    private Node currentNode = null;

    /** To save memory, only one instance of AttributesImpl will be used. */

    private final AttributesImpl atts = new AttributesImpl();

    /** This handler will receive SAX2 events. */

    private ContentHandler receiver=null;

    private Locator locator=this;

    public DOMScanner() {

    }

    /**

     * Configures the locator object that the SAX {@link ContentHandler} will see.

     */

    public void setLocator( Locator loc ) {

        this.locator = loc;

    }

    public void scan(Object node) throws SAXException {

        if( node instanceof Document ) {

            scan( (Document)node );

        } else {

            scan( (Element)node );

        }

    }

    public void scan( Document doc ) throws SAXException {

        scan( doc.getDocumentElement() );

    }

    public void scan( Element e) throws SAXException {

        setCurrentLocation( e );

        receiver.setDocumentLocator(locator);

        receiver.startDocument();

        NamespaceSupport nss = new NamespaceSupport();

        buildNamespaceSupport( nss, e.getParentNode() );

        for( Enumeration en = nss.getPrefixes(); en.hasMoreElements(); ) {

            String prefix = (String)en.nextElement();

            receiver.startPrefixMapping( prefix, nss.getURI(prefix) );

        }

        visit(e);

        for( Enumeration en = nss.getPrefixes(); en.hasMoreElements(); ) {

            String prefix = (String)en.nextElement();

            receiver.endPrefixMapping( prefix );

        }

        setCurrentLocation( e );

        receiver.endDocument();

    }

    /**

     * Parses a subtree starting from the element e and

     * reports SAX2 events to the specified handler.

     *

     * @deprecated in JAXB 2.0

     *      Use {@link #scan(Element)}

     */

    public void parse( Element e, ContentHandler handler ) throws SAXException {

        // it might be better to set receiver at the constructor.

        receiver = handler;

        setCurrentLocation( e );

        receiver.startDocument();

        receiver.setDocumentLocator(locator);

        visit(e);

        setCurrentLocation( e );

        receiver.endDocument();

    }

    /**

     * Similar to the parse method but it visits the ancestor nodes

     * and properly emulate the all in-scope namespace declarations.

     *

     * @deprecated in JAXB 2.0

     *      Use {@link #scan(Element)}

     */

    public void parseWithContext( Element e, ContentHandler handler ) throws SAXException {

        setContentHandler(handler);

        scan(e);

    }

    /**

     * Recursively visit ancestors and build up {@link NamespaceSupport} oject.

     */

    private void buildNamespaceSupport(NamespaceSupport nss, Node node) {

        if(node==null || node.getNodeType()!=Node.ELEMENT_NODE)

            return;

        buildNamespaceSupport( nss, node.getParentNode() );

        nss.pushContext();

        NamedNodeMap atts = node.getAttributes();

        for( int i=0; i<atts.getLength(); i++ ) {

            Attr a = (Attr)atts.item(i);

            if( "xmlns".equals(a.getPrefix()) ) {

                nss.declarePrefix( a.getLocalName(), a.getValue() );

                continue;

            }

            if( "xmlns".equals(a.getName()) ) {

                nss.declarePrefix( "", a.getValue() );

                continue;

            }

        }

    }

    /**

     * Visits an element and its subtree.

     */

    public void visit( Element e ) throws SAXException {

        setCurrentLocation( e );

        final NamedNodeMap attributes = e.getAttributes();

        atts.clear();

        int len = attributes==null ? 0: attributes.getLength();

        for( int i=len-1; i>=0; i-- ) {

            Attr a = (Attr)attributes.item(i);

            String name = a.getName();

            // start namespace binding

           if(name.startsWith("xmlns")) {

                if(name.length()==5) {

                    receiver.startPrefixMapping( "", a.getValue() );

                } else {

                    String localName = a.getLocalName();

                    if(localName==null) {

                        // DOM built without namespace support has this problem

                        localName = name.substring(6);

                    }

                    receiver.startPrefixMapping( localName, a.getValue() );

                }

                continue;

            }

            String uri = a.getNamespaceURI();

            if(uri==null)   uri="";

            String local = a.getLocalName();

            if(local==null) local = a.getName();

            // add other attributes to the attribute list

            // that we will pass to the ContentHandler

            atts.addAttribute(

                uri,

                local,

                a.getName(),

                "CDATA",

                a.getValue());

        }

        String uri = e.getNamespaceURI();

        if(uri==null)   uri="";

        String local = e.getLocalName();

        String qname = e.getTagName();

        if(local==null) local = qname;

        receiver.startElement( uri, local, qname, atts );

        // visit its children

        NodeList children = e.getChildNodes();

        int clen = children.getLength();

        for( int i=0; i<clen; i++ )

            visit(children.item(i));

        setCurrentLocation( e );

        receiver.endElement( uri, local, qname );

        // call the endPrefixMapping method

        for( int i=len-1; i>=0; i-- ) {

            Attr a = (Attr)attributes.item(i);

            String name = a.getName();

            if(name.startsWith("xmlns")) {

                if(name.length()==5)

                    receiver.endPrefixMapping("");

                else

                    receiver.endPrefixMapping(a.getLocalName());

            }

        }

    }

    private void visit( Node n ) throws SAXException {

        setCurrentLocation( n );

        // if a case statement gets too big, it should be made into a separate method.

        switch(n.getNodeType()) {

        case Node.CDATA_SECTION_NODE:

        case Node.TEXT_NODE:

            String value = n.getNodeValue();

            receiver.characters( value.toCharArray(), 0, value.length() );

            break;

        case Node.ELEMENT_NODE:

            visit( (Element)n );

            break;

        case Node.ENTITY_REFERENCE_NODE:

            receiver.skippedEntity(n.getNodeName());

            break;

        case Node.PROCESSING_INSTRUCTION_NODE:

            ProcessingInstruction pi = (ProcessingInstruction)n;

            receiver.processingInstruction(pi.getTarget(),pi.getData());

            break;

        }

    }

    private void setCurrentLocation( Node currNode ) {

        currentNode = currNode;

    }

    /**

     * The same as {@link #getCurrentElement()} but

     * better typed.

     */

    public Node getCurrentLocation() {

        return currentNode;

    }

    public Object getCurrentElement() {

        return currentNode;

    }

    public LocatorEx getLocator() {

        return this;

    }

    public void setContentHandler(ContentHandler handler) {

        this.receiver = handler;

    }

    public ContentHandler getContentHandler() {

        return this.receiver;

    }

    // LocatorEx implementation

    public String getPublicId() { return null; }

    public String getSystemId() { return null; }

    public int getLineNumber() { return -1; }

    public int getColumnNumber() { return -1; }

    public ValidationEventLocator getLocation() {

        return new ValidationEventLocatorImpl(getCurrentLocation());

    }

}