001/*
002 * Copyright (c) 2011, 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.feature;
025
026import java.util.Collections;
027import java.util.List;
028
029import org.apache.uima.jcas.JCas;
030import org.apache.uima.jcas.tcas.Annotation;
031import org.cleartk.ml.Feature;
032import org.cleartk.ml.feature.extractor.CleartkExtractorException;
033import org.cleartk.ml.feature.extractor.FeatureExtractor1;
034import org.cleartk.ml.feature.extractor.NamingExtractor1;
035
036/**
037 * <br>
038 * Copyright (c) 2011, Regents of the University of Colorado <br>
039 * All rights reserved.
040 * 
041 * @author Steven Bethard
042 */
043public abstract class FilteringExtractor<T extends Annotation> implements FeatureExtractor1<T> {
044
045  private Class<T> annotationClass;
046
047  private FeatureExtractor1<T> extractor;
048
049  public FilteringExtractor(Class<T> annotationClass, FeatureExtractor1<T> extractor) {
050    this.annotationClass = annotationClass;
051    this.extractor = extractor;
052  }
053
054  public FilteringExtractor(Class<T> annotationClass, String name, FeatureExtractor1<T> extractor) {
055    this.annotationClass = annotationClass;
056    this.extractor = new NamingExtractor1<T>(name, extractor);
057  }
058
059  @Override
060  public List<Feature> extract(JCas view, T focusAnnotation)
061      throws CleartkExtractorException {
062    if (this.accept(annotationClass.cast(focusAnnotation))) {
063      return this.extractor.extract(view, focusAnnotation);
064    } else {
065      return Collections.emptyList();
066    }
067  }
068
069  protected abstract boolean accept(T annotation);
070
071}