content: /**
   * 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.
   */
  
  package org.apache.solr.analysis;
  
  import org.apache.lucene.analysis.FilteringTokenFilter;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.analysis.CharArraySet;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  
  import java.io.IOException;
  import java.util.Set;
  
  /**
   * A TokenFilter that only keeps tokens with text contained in the
   * required words.  This filter behaves like the inverse of StopFilter.
   * 
   * @version $Id: KeepWordFilter.java 1065324 2011-01-30 17:20:39Z uschindler $
   * @since solr 1.3
   */
  public final class KeepWordFilter extends FilteringTokenFilter {
    private final CharArraySet words;
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
  
    /** @deprecated Use {@link #KeepWordFilter(boolean, TokenStream, CharArraySet)} instead */
    @Deprecated
    public KeepWordFilter(TokenStream in, Set<String> words, boolean ignoreCase ) {
      this(false, in, new CharArraySet(words, ignoreCase));
    }
  
    /** The words set passed to this constructor will be directly used by this filter
     * and should not be modified, */
    public KeepWordFilter(boolean enablePositionIncrements, TokenStream in, CharArraySet words) {
      super(enablePositionIncrements, in);
      this.words = words;
    }
  
    @Override
    public boolean accept() throws IOException {
      return words.contains(termAtt.buffer(), 0, termAtt.length());
    }
  }
  