XMLRootNamespaceParser.java

/**
 * 
 */
package uk.bl.wa.parsers;

/*
 * #%L
 * warc-indexer
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2013 - 2014 The UK Web Archive
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-2.0.html>.
 * #L%
 */

import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import javax.xml.namespace.QName;

import org.apache.tika.detect.XmlRootExtractor;
import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.Property;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.AbstractParser;
import org.apache.tika.parser.ParseContext;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

/**
 * @author Andrew Jackson <Andrew.Jackson@bl.uk>
 *
 */
public class XMLRootNamespaceParser extends AbstractParser {

    /** */
	private static final long serialVersionUID = 710873621129254338L;

	/** */
	private static final Set<MediaType> SUPPORTED_TYPES =
            Collections.unmodifiableSet(new HashSet<MediaType>(Arrays.asList(
            	  MediaType.APPLICATION_XML
            )));

	public static final Property XML_ROOT_NS = Property.internalText("XML_ROOT_NS");

	/* (non-Javadoc)
	 * @see org.apache.tika.parser.Parser#getSupportedTypes(org.apache.tika.parser.ParseContext)
	 */
	@Override
	public Set<MediaType> getSupportedTypes(ParseContext context) {
		return SUPPORTED_TYPES;
	}

	/* (non-Javadoc)
	 * @see org.apache.tika.parser.Parser#parse(java.io.InputStream, org.xml.sax.ContentHandler, org.apache.tika.metadata.Metadata, org.apache.tika.parser.ParseContext)
	 */
	@Override
	public void parse(InputStream stream, ContentHandler handler,
			Metadata metadata, ParseContext context) throws IOException,
			SAXException, TikaException {
		
		QName qname = new XmlRootExtractor().extractRootElement( stream );
		if( qname != null ) {
			if( qname.getNamespaceURI() != null && ( !"".equals( qname.getNamespaceURI().trim() ) ) ) {
				//log.info( "rootXML: " + qname.getLocalPart() + " prefix:" + qname.getPrefix() + " nsURI:" + qname.getNamespaceURI() );
				metadata.set( XML_ROOT_NS, qname.getNamespaceURI().toLowerCase() + "#" + qname.getLocalPart().toLowerCase() );
			}
		}
	}

}