content: package org.apache.lucene.analysis.en;
  
  /**
   * 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 org.apache.lucene.analysis.TokenFilter;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  
  /**
   * TokenFilter that removes possessives (trailing 's) from words.
   */
  public final class EnglishPossessiveFilter extends TokenFilter {
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
  
    public EnglishPossessiveFilter(TokenStream input) {
      super(input);
    }
  
    @Override
    public boolean incrementToken() throws IOException {
      if (!input.incrementToken()) {
        return false;
      }
      
      final char[] buffer = termAtt.buffer();
      final int bufferLength = termAtt.length();
      
      if (bufferLength >= 2 &&
          buffer[bufferLength-2] == '\'' &&
          (buffer[bufferLength-1] == 's' || buffer[bufferLength-1] == 'S'))
        termAtt.setLength(bufferLength - 2); // Strip last 2 characters off
  
      return true;
    }
  }
  