org.hibernate.search.util.AnalyzerUtils.java Source code

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Here is the source code for org.hibernate.search.util.AnalyzerUtils.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat, Inc. and/or its affiliates or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat, Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.search.util;

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;

import org.hibernate.search.util.logging.impl.Log;
import org.hibernate.search.util.logging.impl.LoggerFactory;

/**
 * Helper class to test analyzers. Taken and modified from <i>Lucene in Action</i>.
 *
 * @author Hardy Ferentschik
 */
public class AnalyzerUtils {

    public static final Log log = LoggerFactory.make();

    public static List<String> tokenizedTermValues(Analyzer analyzer, String field, String text)
            throws IOException {
        TokenStream stream = analyzer.tokenStream(field, new StringReader(text));
        CharTermAttribute term = stream.addAttribute(CharTermAttribute.class);
        List<String> tokenList = new ArrayList<String>();
        while (stream.incrementToken()) {
            String s = new String(term.buffer(), 0, term.length());
            tokenList.add(s);
        }
        return tokenList;
    }

    public static Token[] tokensFromAnalysis(Analyzer analyzer, String field, String text) throws IOException {
        TokenStream stream = analyzer.tokenStream(field, new StringReader(text));
        CharTermAttribute term = stream.addAttribute(CharTermAttribute.class);
        List<Token> tokenList = new ArrayList<Token>();
        while (stream.incrementToken()) {
            Token token = new Token();
            token.copyBuffer(term.buffer(), 0, term.length());
            tokenList.add(token);
        }

        return tokenList.toArray(new Token[tokenList.size()]);
    }

    public static void displayTokens(Analyzer analyzer, String field, String text) throws IOException {
        Token[] tokens = tokensFromAnalysis(analyzer, field, text);

        for (Token token : tokens) {
            log.debug("[" + getTermText(token) + "] ");
        }
    }

    public static void displayTokensWithPositions(Analyzer analyzer, String field, String text) throws IOException {
        Token[] tokens = tokensFromAnalysis(analyzer, field, text);

        int position = 0;

        for (Token token : tokens) {
            int increment = token.getPositionIncrement();

            if (increment > 0) {
                position = position + increment;
                System.out.println();
                System.out.print(position + ": ");
            }

            log.debug("[" + getTermText(token) + "] ");
        }
    }

    public static void displayTokensWithFullDetails(Analyzer analyzer, String field, String text)
            throws IOException {
        Token[] tokens = tokensFromAnalysis(analyzer, field, text);
        StringBuilder builder = new StringBuilder();
        int position = 0;

        for (Token token : tokens) {
            int increment = token.getPositionIncrement();

            if (increment > 0) {
                position = position + increment;
                builder.append("\n").append(position).append(": ");
            }

            builder.append("[").append(getTermText(token)).append(":").append(token.startOffset()).append("->")
                    .append(token.endOffset()).append(":").append(token.type()).append("] ");
            log.debug(builder.toString());
        }
    }

    public static String getTermText(Token token) {
        return new String(token.buffer(), 0, token.length());
    }
}