SentimentJTextAnalyser.java

/**
 * 
 */
package uk.bl.wa.analyser.text;

/*
 * #%L
 * warc-indexer
 * %%
 * 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.typesafe.config.Config;

import uk.bl.wa.sentimentalj.Sentiment;
import uk.bl.wa.sentimentalj.SentimentalJ;
import uk.bl.wa.solr.SolrFields;
import uk.bl.wa.solr.SolrRecord;

/**
 * @author anj
 *
 */
public class SentimentJTextAnalyser extends AbstractTextAnalyser {
	private static Log log = LogFactory.getLog( SentimentJTextAnalyser.class );

	/** */
	private static SentimentalJ sentij = new SentimentalJ();

	/**
	 * @param conf
	 */
	public SentimentJTextAnalyser(Config conf) {
	}

	/**
	 * 
	 */
	public void analyse( String text, SolrRecord solr ) {
		// Sentiment Analysis:
		int sentilen = 10000;
		if( sentilen > text.length() )
			sentilen = text.length();
		String sentitext = text.substring( 0, sentilen );
		// metadata.get(HtmlFeatureParser.FIRST_PARAGRAPH);

		Sentiment senti = sentij.analyze( sentitext );
		double sentilog = Math.signum( senti.getComparative() ) * ( Math.log( 1.0 + Math.abs( senti.getComparative() ) ) / 40.0 );
		int sentii = ( int ) ( SolrFields.SENTIMENTS.length * ( 0.5 + sentilog ) );
		if( sentii < 0 ) {
			log.debug( "Caught a sentiment rating less than zero: " + sentii + " from " + sentilog );
			sentii = 0;
		}
		if( sentii >= SolrFields.SENTIMENTS.length ) {
			log.debug( "Caught a sentiment rating too large to be in range: " + sentii + " from " + sentilog );
			sentii = SolrFields.SENTIMENTS.length - 1;
		}
		// if( sentii != 3 )
		// log.debug("Got sentiment: " + sentii+" "+sentilog+" "+ SolrFields.SENTIMENTS[sentii] );
		// Map to sentiment scale:
		solr.addField( SolrFields.SENTIMENT, SolrFields.SENTIMENTS[ sentii ] );
		solr.addField( SolrFields.SENTIMENT_SCORE, "" + senti.getComparative() );
	}
}