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 * 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,

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 *

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package com.sun.xml.internal.bind.v2.runtime.unmarshaller;

import java.util.Iterator;

import javax.xml.namespace.QName;

import javax.xml.stream.Location;

import javax.xml.stream.XMLEventReader;

import javax.xml.stream.XMLStreamConstants;

import javax.xml.stream.XMLStreamException;

import javax.xml.stream.events.Attribute;

import javax.xml.stream.events.Characters;

import javax.xml.stream.events.EndElement;

import javax.xml.stream.events.Namespace;

import javax.xml.stream.events.StartElement;

import javax.xml.stream.events.XMLEvent;

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.AttributesImpl;

/**

 * This is a simple utility class that adapts StAX events from an

 * {@link XMLEventReader} to unmarshaller events on a

 * {@link XmlVisitor}, bridging between the two

 * parser technologies.

 *

 * @author Ryan.Shoemaker@Sun.COM

 * @version 1.0

 */

final class StAXEventConnector extends StAXConnector {

    // StAX event source

    private final XMLEventReader staxEventReader;

    /** Current event. */

    private XMLEvent event;

    /**

     * Shared and reused {@link Attributes}.

     */

    private final AttributesImpl attrs = new AttributesImpl();

    /**

     * SAX may fire consective characters event, but we don't allow it.

     * so use this buffer to perform buffering.

     */

    private final StringBuilder buffer = new StringBuilder();

    private boolean seenText;

    /**

     * Construct a new StAX to SAX adapter that will convert a StAX event

     * stream into a SAX event stream.

     *

     * @param staxCore

     *                StAX event source

     * @param visitor

     *                sink

     */

    public StAXEventConnector(XMLEventReader staxCore, XmlVisitor visitor) {

        super(visitor);

        staxEventReader = staxCore;

    }

    public void bridge() throws XMLStreamException {

        try {

            // remembers the nest level of elements to know when we are done.

            int depth=0;

            event = staxEventReader.peek();

            if( !event.isStartDocument() && !event.isStartElement() )

                throw new IllegalStateException();

            // if the parser is on START_DOCUMENT, skip ahead to the first element

            do {

                event = staxEventReader.nextEvent();

            } while( !event.isStartElement() );

            handleStartDocument(event.asStartElement().getNamespaceContext());

            OUTER:

            while(true) {

                // These are all of the events listed in the javadoc for

                // XMLEvent.

                // The spec only really describes 11 of them.

                switch (event.getEventType()) {

                    case XMLStreamConstants.START_ELEMENT :

                        handleStartElement(event.asStartElement());

                        depth++;

                        break;

                    case XMLStreamConstants.END_ELEMENT :

                        depth--;

                        handleEndElement(event.asEndElement());

                        if(depth==0)    break OUTER;

                        break;

                    case XMLStreamConstants.CHARACTERS :

                    case XMLStreamConstants.CDATA :

                    case XMLStreamConstants.SPACE :

                        handleCharacters(event.asCharacters());

                        break;

                }

                event=staxEventReader.nextEvent();

            }

            handleEndDocument();

            event = null; // avoid keeping a stale reference

        } catch (SAXException e) {

            throw new XMLStreamException(e);

        }

    }

    protected Location getCurrentLocation() {

        return event.getLocation();

    }

    protected String getCurrentQName() {

        QName qName;

        if(event.isEndElement())

            qName = event.asEndElement().getName();

        else

            qName = event.asStartElement().getName();

        return getQName(qName.getPrefix(), qName.getLocalPart());

    }

    private void handleCharacters(Characters event) throws SAXException, XMLStreamException {

        if(!predictor.expectText())

            return;     // text isn't expected. simply skip

        seenText = true;

        // check the next event

        XMLEvent next;

        while(true) {

            next = staxEventReader.peek();

            if(!isIgnorable(next))

                break;

            staxEventReader.nextEvent();

        }

        if(isTag(next)) {

            // this is by far the common case --- you have <foo>abc</foo> or <foo>abc<bar/>...</foo>

            visitor.text(event.getData());

            return;

        }

        // otherwise we have things like "abc<!-- test -->def".

        // concatenate all text

        buffer.append(event.getData());

        while(true) {

            while(true) {

                next = staxEventReader.peek();

                if(!isIgnorable(next))

                    break;

                staxEventReader.nextEvent();

            }

            if(isTag(next)) {

                // found all adjacent text

                visitor.text(buffer);

                buffer.setLength(0);

                return;

            }

            buffer.append(next.asCharacters().getData());

            staxEventReader.nextEvent();    // consume

        }

    }

    private boolean isTag(XMLEvent event) {

        int eventType = event.getEventType();

        return eventType==XMLEvent.START_ELEMENT || eventType==XMLEvent.END_ELEMENT;

    }

    private boolean isIgnorable(XMLEvent event) {

        int eventType = event.getEventType();

        return eventType==XMLEvent.COMMENT || eventType==XMLEvent.PROCESSING_INSTRUCTION;

    }

    private void handleEndElement(EndElement event) throws SAXException {

        if(!seenText && predictor.expectText()) {

            visitor.text("");

        }

        // fire endElement

        QName qName = event.getName();

        tagName.uri = fixNull(qName.getNamespaceURI());

        tagName.local = qName.getLocalPart();

        visitor.endElement(tagName);

        // end namespace bindings

        for( Iterator<Namespace> i = event.getNamespaces(); i.hasNext();) {

            String prefix = fixNull(i.next().getPrefix());  // be defensive

            visitor.endPrefixMapping(prefix);

        }

        seenText = false;

    }

    private void handleStartElement(StartElement event) throws SAXException {

        // start namespace bindings

        for (Iterator i = event.getNamespaces(); i.hasNext();) {

            Namespace ns = (Namespace)i.next();

            visitor.startPrefixMapping(

                fixNull(ns.getPrefix()),

                fixNull(ns.getNamespaceURI()));

        }

        // fire startElement

        QName qName = event.getName();

        tagName.uri = fixNull(qName.getNamespaceURI());

        String localName = qName.getLocalPart();

        tagName.uri = fixNull(qName.getNamespaceURI());

        tagName.local = localName;

        tagName.atts = getAttributes(event);

        visitor.startElement(tagName);

        seenText = false;

    }

    /**

     * Get the attributes associated with the given START_ELEMENT StAXevent.

     *

     * @return the StAX attributes converted to an org.xml.sax.Attributes

     */

    private Attributes getAttributes(StartElement event) {

        attrs.clear();

        // in SAX, namespace declarations are not part of attributes by default.

        // (there's a property to control that, but as far as we are concerned

        // we don't use it.) So don't add xmlns:* to attributes.

        // gather non-namespace attrs

        for (Iterator i = event.getAttributes(); i.hasNext();) {

            Attribute staxAttr = (Attribute)i.next();

            QName name = staxAttr.getName();

            String uri = fixNull(name.getNamespaceURI());

            String localName = name.getLocalPart();

            String prefix = name.getPrefix();

            String qName;

            if (prefix == null || prefix.length() == 0)

                qName = localName;

            else

                qName = prefix + ':' + localName;

            String type = staxAttr.getDTDType();

            String value = staxAttr.getValue();

            attrs.addAttribute(uri, localName, qName, type, value);

        }

        return attrs;

    }

}