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

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 * accompanied this code).

 *

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package com.sun.xml.internal.ws.encoding;

import org.xml.sax.helpers.AttributesImpl;

import org.xml.sax.ContentHandler;

import org.xml.sax.SAXException;

import javax.xml.stream.XMLStreamReader;

import javax.xml.stream.XMLStreamWriter;

import javax.xml.stream.XMLStreamException;

import com.sun.xml.internal.ws.message.stream.StreamMessage;

import com.sun.xml.internal.ws.encoding.StreamSOAPCodec;

import com.sun.istack.internal.Nullable;

import com.sun.istack.internal.NotNull;

/**

 * Complete infoset about a start tag.

 *

 * <p>

 * This is used between {@link StreamMessage} and {@link StreamSOAPCodec}

 * to capture the infoset of the s:Envelope, s:Header, and s:Body elements.

 *

 *

 * <h3>Design Note</h3>

 * <p>

 * Since StAX and SAX uses different null vs empty string convention, one has

 * to choose which format we store things. It can go either way, but I'm assuming

 * that we'll be using StAX more in JAX-WS, so things are kept in the StAX style

 * in this class.

 *

 * @author Kohsuke Kawaguchi

 */

public final class TagInfoset {

    /**

     * Namespace declarations on this tag. Read-only.

     *

     * This is an array of the even length of the form { prefix0, uri0, prefix1, uri1, ... }.

     *

     * URIs/prefixes can be null (StAX-style)

     */

    public final @NotNull String[] ns;

    /**

     * Attributes on this tag. Read-only.

     */

    public final @NotNull AttributesImpl atts;

    /**

     * Prefix of the start tag in stax-style.

     */

    public final @Nullable String prefix;

    /**

     * Namespace URI of the start tag in stax-style.

     */

    public final @Nullable String nsUri;

    /**

     * Local name of the start tag.

     */

    public final @NotNull String localName;

    /**

     * Lazily computed QName (i.e., "foo:bar")

     */

    private @Nullable String qname;

    public TagInfoset(String nsUri, String localName, String prefix, AttributesImpl atts, String... ns) {

        this.nsUri = nsUri;

        this.prefix = prefix;

        this.localName = localName;

        this.atts = atts;

        this.ns = ns;

    }

    /**

     * Fills a {@link TagInfoset} object by the current element

     * that the reader points to.

     */

    public TagInfoset(XMLStreamReader reader) {

        prefix = reader.getPrefix();

        nsUri = reader.getNamespaceURI();

        localName = reader.getLocalName();

        int nsc = reader.getNamespaceCount();

        if(nsc>0) {

            ns = new String[nsc*2];

            for(int i=0; i<nsc; i++){

                ns[i*2  ] = fixNull(reader.getNamespacePrefix(i));

                ns[i*2+1] = fixNull(reader.getNamespaceURI(i));

            }

        } else {

            ns = EMPTY_ARRAY;

        }

        int ac = reader.getAttributeCount();

        if(ac>0) {

            atts = new AttributesImpl();

            StringBuilder sb = new StringBuilder();

            for(int i=0; i< ac;i++){

                sb.setLength(0);

                String prefix = reader.getAttributePrefix(i);

                String localName = reader.getAttributeLocalName(i);

                String qname;

                if(prefix != null && prefix.length()!=0){

                    sb.append(prefix);

                    sb.append(":");

                    sb.append(localName);

                    qname = sb.toString();

                } else {

                    qname = localName;

                }

                atts.addAttribute(

                    fixNull(reader.getAttributeNamespace(i)),

                    localName,

                    qname,

                    reader.getAttributeType(i),

                    reader.getAttributeValue(i));

            }

        } else {

            atts = EMPTY_ATTRIBUTES;

        }

    }

    /**

     * Writes the start element event.

     */

    public void writeStart(ContentHandler contentHandler) throws SAXException {

        for( int i=0; i<ns.length; i+=2 )

            contentHandler.startPrefixMapping(fixNull(ns[i]),fixNull(ns[i+1]));

        contentHandler.startElement(fixNull(nsUri), localName ,getQName(), atts);

    }

    /**

     * Writes the end element event.

     */

    public void writeEnd(ContentHandler contentHandler) throws SAXException{

        contentHandler.endElement(fixNull(nsUri),localName,getQName());

        for( int i=ns.length-2; i>=0; i-=2 ) {

            contentHandler.endPrefixMapping(fixNull(ns[i]));

        }

    }

    /**

     * Writes the start element event.

     */

    public void writeStart(XMLStreamWriter w) throws XMLStreamException {

        // write start tag.

        if(prefix==null) {

            if(nsUri==null)

                w.writeStartElement(localName);

            else {

                //fix Null prefix. otherwise throws XMLStreamException,

                // if the namespace URI has not been bound to a prefix

                w.writeStartElement("",localName,nsUri);

            }

        } else {

            w.writeStartElement(prefix,localName,nsUri);

        }

        for( int i=0; i<ns.length; i+=2 ) {

            w.writeNamespace(ns[i],ns[i+1]);

        }

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

            String nsUri = atts.getURI(i);

            if(nsUri==null || nsUri.length() ==0) {

                w.writeAttribute(atts.getLocalName(i),atts.getValue(i));

            } else {

                String rawName = atts.getQName(i);

                String prefix = rawName.substring(0,rawName.indexOf(':'));

                w.writeAttribute(prefix,nsUri,atts.getLocalName(i),atts.getValue(i));

            }

        }

    }

    private String getQName() {

        if(qname!=null) return qname;

        StringBuilder sb = new StringBuilder();

        if(prefix!=null){

            sb.append(prefix);

            sb.append(':');

            sb.append(localName);

            qname = sb.toString();

        } else {

            qname = localName;

        }

        return qname;

    }

    private static String fixNull(String s) {

        if(s==null) return "";

        else        return s;

    }

    private static final String[] EMPTY_ARRAY = new String[0];

    private static final AttributesImpl EMPTY_ATTRIBUTES = new AttributesImpl();

}