content: package org.apache.lucene.analysis;
  
  /**
   * 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.io.Reader;
  
  import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  import org.apache.lucene.util.AttributeSource;
  
  /**
   * Emits the entire input as a single token.
   */
  public final class KeywordTokenizer extends Tokenizer {
    
    private static final int DEFAULT_BUFFER_SIZE = 256;
  
    private boolean done = false;
    private int finalOffset;
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
    
    public KeywordTokenizer(Reader input) {
      this(input, DEFAULT_BUFFER_SIZE);
    }
  
    public KeywordTokenizer(Reader input, int bufferSize) {
      super(input);
      termAtt.resizeBuffer(bufferSize);
    }
  
    public KeywordTokenizer(AttributeSource source, Reader input, int bufferSize) {
      super(source, input);
      termAtt.resizeBuffer(bufferSize);
    }
  
    public KeywordTokenizer(AttributeFactory factory, Reader input, int bufferSize) {
      super(factory, input);
      termAtt.resizeBuffer(bufferSize);
    }
    
    @Override
    public final boolean incrementToken() throws IOException {
      if (!done) {
        clearAttributes();
        done = true;
        int upto = 0;
        char[] buffer = termAtt.buffer();
        while (true) {
          final int length = input.read(buffer, upto, buffer.length-upto);
          if (length == -1) break;
          upto += length;
          if (upto == buffer.length)
            buffer = termAtt.resizeBuffer(1+buffer.length);
        }
        termAtt.setLength(upto);
        finalOffset = correctOffset(upto);
        offsetAtt.setOffset(correctOffset(0), finalOffset);
        return true;
      }
      return false;
    }
    
    @Override
    public final void end() {
      // set final offset 
      offsetAtt.setOffset(finalOffset, finalOffset);
    }
  
    @Override
    public void reset(Reader input) throws IOException {
      super.reset(input);
      this.done = false;
    }
  }
  