uk.nhs.cfh.dsp.yasb.indexgenerator.analyser.SynonymAnalyser.java Source code

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Here is the source code for uk.nhs.cfh.dsp.yasb.indexgenerator.analyser.SynonymAnalyser.java

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/**
 * Crown Copyright (C) 2008 - 2011
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * 
 */
package uk.nhs.cfh.dsp.yasb.indexgenerator.analyser;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.LowerCaseFilter;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import uk.nhs.cfh.dsp.yasb.indexgenerator.engine.SynonymEngine;
import uk.nhs.cfh.dsp.yasb.indexgenerator.filter.SynonymFilter;

import java.io.Reader;

// TODO: Auto-generated Javadoc
/**
 * A custom analyser for SNOMED synonyms based on 'Lucene in Action' example
 * Written by @author jay
 * Created on Jan 12, 2009 at 6:13:00 PM.
 */
public class SynonymAnalyser extends Analyzer {

    /** The synonym engine. */
    private SynonymEngine synonymEngine;

    /**
     * Instantiates a new synonym analyser.
     *
     * @param synonymEngine the synonym engine
     */
    public SynonymAnalyser(SynonymEngine synonymEngine) {
        this.synonymEngine = synonymEngine;
    }

    /* (non-Javadoc)
     * @see org.apache.lucene.analysis.Analyzer#tokenStream(java.lang.String, java.io.Reader)
     */
    @Override
    public TokenStream tokenStream(String fieldName, Reader reader) {

        TokenStream stream = new SynonymFilter(
                new StopFilter(new LowerCaseFilter(new StandardFilter(new StandardTokenizer(reader))),
                        StandardAnalyzer.STOP_WORDS),
                synonymEngine);

        return stream;
    }

}