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

 *

 * This code is free software; you can redistribute it and/or modify it

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.xml.internal.xsom.parser;

import java.io.IOException;

import java.net.URL;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.helpers.XMLFilterImpl;

import com.sun.xml.internal.xsom.impl.parser.Messages;

/**

 * Standard XMLParser implemented by using JAXP.

 *

 * @author

 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)

 */

public class JAXPParser implements XMLParser {

    private final SAXParserFactory factory;

    public JAXPParser( SAXParserFactory factory ) {

        factory.setNamespaceAware(true);    // just in case

        this.factory = factory;

    }

    public JAXPParser() {

        this( SAXParserFactory.newInstance());

    }

    public void parse( InputSource source, ContentHandler handler,

        ErrorHandler errorHandler, EntityResolver entityResolver )

        throws SAXException, IOException {

        try {

            reader.setContentHandler(handler);

            if(errorHandler!=null)

                reader.setErrorHandler(errorHandler);

            if(entityResolver!=null)

                reader.setEntityResolver(entityResolver);

            reader.parse(source);

        } catch( ParserConfigurationException e ) {

            // in practice this won't happen

            SAXParseException spe = new SAXParseException(e.getMessage(),null,e);

            errorHandler.fatalError(spe);

            throw spe;

        }

    }

    /**

     * XMLReader with improved error message for entity resolution failure.

     *

     * TODO: this class is completely stand-alone, so it shouldn't be

     * an inner class.

     */

    private static class XMLReaderEx extends XMLFilterImpl {

        private Locator locator;

        XMLReaderEx( XMLReader parent ) {

            this.setParent(parent);

        }

        /**

         * Resolves entities and reports user-friendly error messages.

         *

         * <p>

         * Some XML parser (at least Xerces) does not report much information

         * when it fails to resolve an entity, which is often quite

         * frustrating. For example, if you are behind a firewall and the

         * schema contains a reference to www.w3.org, and there is no

         * entity resolver, the parser will just throw an IOException

         * that doesn't contain any information about where that reference

         * occurs nor what it is accessing.

         *

         * <p>

         * By implementing an EntityResolver and resolving the reference

         * by ourselves, we can report an error message with all the

         * necessary information to fix the problem.

         *

         * <p>

         * Note that we still need to the client-specified entity resolver

         * to let the application handle entity resolution. Here we just catch

         * an IOException and add more information.

         */

        @Override

        public InputSource resolveEntity(String publicId, String systemId) throws SAXException {

            try {

                InputSource is=null;

                // ask the client-specified entity resolver first

                if( this.getEntityResolver()!=null)

                    is = this.getEntityResolver().resolveEntity(publicId,systemId);

                if( is!=null )  return is;  // if that succeeds, fine.

                // rather than returning null, resolve it now

                // so that we can detect errors.

                is = new InputSource( new URL(systemId).openStream() );

                is.setSystemId(systemId);

                is.setPublicId(publicId);

                return is;

            } catch( IOException e ) {

                // catch this error and provide a nice error message, rather than

                // just throwing this IOException.

                SAXParseException spe = new SAXParseException(

                    Messages.format(Messages.ERR_ENTITY_RESOLUTION_FAILURE,

                        systemId, e.toString()),    // use the toString method to get the class name

                    locator, e );

                if(this.getErrorHandler()!=null)

                    this.getErrorHandler().fatalError(spe);

                throw spe;

            }

        }

        @Override

        public void setDocumentLocator(Locator locator) {

            super.setDocumentLocator(locator);

            this.locator = locator;

        }

    }

}