lucene 4.0에서 reuseStrategy 설명

createComponents.java

@Override
  protected TokenStreamComponents createComponents(final String fieldName,
      final Reader reader) {
    return new TokenStreamComponents(new WhitespaceTokenizer(matchVersion, reader));
  }

getReusableComponents.java

@Override
    public TokenStreamComponents getReusableComponents(String fieldName) {
      return (TokenStreamComponents) getStoredValue();
    }

tokenStream.java

public final TokenStream tokenStream(final String fieldName,
                                       final Reader reader) throws IOException {
    TokenStreamComponents components = reuseStrategy.getReusableComponents(fieldName);
    final Reader r = initReader(fieldName, reader);
    if (components == null) {
      components = createComponents(fieldName, r);
      reuseStrategy.setReusableComponents(fieldName, components);
    } else {
      components.setReader(r);
    }
    return components.getTokenStream();
  }