001/** 
002 * Copyright (c) 2007-2009, Regents of the University of Colorado 
003 * All rights reserved.
004 * 
005 * Redistribution and use in source and binary forms, with or without
006 * modification, are permitted provided that the following conditions are met:
007 * 
008 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
009 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 
010 * Neither the name of the University of Colorado at Boulder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 
011 * 
012 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
013 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
014 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
015 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
016 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
017 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
018 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
019 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
020 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
021 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
022 * POSSIBILITY OF SUCH DAMAGE. 
023 */
024package org.cleartk.snowball;
025
026import org.apache.lucene.analysis.snowball.SnowballFilter;
027import org.apache.uima.UimaContext;
028import org.apache.uima.analysis_engine.AnalysisEngineProcessException;
029import org.apache.uima.cas.FSIterator;
030import org.apache.uima.cas.Type;
031import org.apache.uima.jcas.JCas;
032import org.apache.uima.jcas.tcas.Annotation;
033import org.apache.uima.resource.ResourceInitializationException;
034import org.cleartk.util.ReflectionUtil;
035import org.tartarus.snowball.SnowballProgram;
036import org.apache.uima.fit.component.JCasAnnotator_ImplBase;
037import org.apache.uima.fit.descriptor.ConfigurationParameter;
038import org.apache.uima.fit.factory.initializable.InitializableFactory;
039import org.apache.uima.fit.util.JCasUtil;
040
041/**
042 * This class borrows from {@link SnowballFilter}
043 * 
044 * <br>
045 * Copyright (c) 2007-2009, Regents of the University of Colorado <br>
046 * All rights reserved.
047 * 
048 * 
049 * @author Philip Ogren
050 */
051public abstract class SnowballStemmer<TOKEN_TYPE extends Annotation> extends JCasAnnotator_ImplBase {
052
053  public static final String PARAM_STEMMER_NAME = "stemmerName";
054
055  private static final String STEMMER_NAME_DESCRIPTION = "specifies which snowball stemmer to use. Possible values are: "
056      + "Danish, Dutch, English, Finnish, French, German2, German, Italian, Kp, Lovins, Norwegian, Porter, Portuguese, Russian, Spanish, Swedish";
057
058  @ConfigurationParameter(
059      name = PARAM_STEMMER_NAME,
060      description = STEMMER_NAME_DESCRIPTION,
061      mandatory = true)
062  public String stemmerName;
063
064  private SnowballProgram stemmer;
065
066  private Class<? extends Annotation> tokenClass;
067
068  private Type tokenType = null;
069
070  private boolean typesInitialized = false;
071
072  @Override
073  public void initialize(UimaContext context) throws ResourceInitializationException {
074    super.initialize(context);
075    String className = String.format("org.tartarus.snowball.ext.%sStemmer", stemmerName);
076    this.stemmer = InitializableFactory.create(null, className, SnowballProgram.class);
077
078    this.tokenClass = ReflectionUtil.<Class<? extends Annotation>> uncheckedCast(ReflectionUtil.getTypeArgument(
079        SnowballStemmer.class,
080        "TOKEN_TYPE",
081        this));
082  }
083
084  private void initializeTypes(JCas jCas) {
085    if (tokenClass != null) {
086      tokenType = JCasUtil.getType(jCas, tokenClass);
087    }
088    typesInitialized = true;
089  }
090
091  @SuppressWarnings("unchecked")
092  @Override
093  public void process(JCas jCas) throws AnalysisEngineProcessException {
094    if (!typesInitialized)
095      initializeTypes(jCas);
096
097    FSIterator<Annotation> tokens = jCas.getAnnotationIndex(tokenType).iterator();
098    while (tokens.hasNext()) {
099      TOKEN_TYPE token = (TOKEN_TYPE) tokens.next();
100      stemmer.setCurrent(token.getCoveredText().toLowerCase());
101      stemmer.stem();
102      String stem = stemmer.getCurrent();
103      setStem(token, stem);
104    }
105  }
106
107  public abstract void setStem(TOKEN_TYPE token, String stem);
108
109  public void setStemmerName(String stemmerName) {
110    this.stemmerName = stemmerName;
111  }
112
113}