content: package org.apache.lucene.analysis.br;
  
  /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.
   */
  
  import java.io.IOException;
  import java.util.Set;
  
  import org.apache.lucene.analysis.KeywordMarkerFilter; // for javadoc
  import org.apache.lucene.analysis.TokenFilter;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  
  /**
   * A {@link TokenFilter} that applies {@link BrazilianStemmer}.
   * <p>
   * To prevent terms from being stemmed use an instance of
   * {@link KeywordMarkerFilter} or a custom {@link TokenFilter} that sets
   * the {@link KeywordAttribute} before this {@link TokenStream}.
   * </p>
   * @see KeywordMarkerFilter
   * 
   */
  public final class BrazilianStemFilter extends TokenFilter {
  
    /**
     * {@link BrazilianStemmer} in use by this filter.
     */
    private BrazilianStemmer stemmer = new BrazilianStemmer();
    private Set<?> exclusions = null;
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private final KeywordAttribute keywordAttr = addAttribute(KeywordAttribute.class);
  
    /**
     * Creates a new BrazilianStemFilter 
     * 
     * @param in the source {@link TokenStream} 
     */
    public BrazilianStemFilter(TokenStream in) {
      super(in);
    }
    
    /**
     * Creates a new BrazilianStemFilter 
     * 
     * @param in the source {@link TokenStream} 
     * @param exclusiontable a set of terms that should be prevented from being stemmed.
     * @deprecated use {@link KeywordAttribute} with {@link KeywordMarkerFilter} instead.
     */
    @Deprecated
    public BrazilianStemFilter(TokenStream in, Set<?> exclusiontable) {
      this(in);
      this.exclusions = exclusiontable;
    }
  
    @Override
    public boolean incrementToken() throws IOException {
      if (input.incrementToken()) {
        final String term = termAtt.toString();
        // Check the exclusion table.
        if (!keywordAttr.isKeyword() && (exclusions == null || !exclusions.contains(term))) {
          final String s = stemmer.stem(term);
          // If not stemmed, don't waste the time adjusting the token.
          if ((s != null) && !s.equals(term))
            termAtt.setEmpty().append(s);
        }
        return true;
      } else {
        return false;
      }
    }
  }
  
  
  