content: package org.apache.lucene.analysis.cjk;
  
  /**
   * 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 org.apache.lucene.analysis.Analyzer;
  import org.apache.lucene.analysis.CharArraySet;
  import org.apache.lucene.analysis.StopFilter;
  import org.apache.lucene.analysis.StopwordAnalyzerBase;
  import org.apache.lucene.analysis.Tokenizer;
  import org.apache.lucene.util.Version;
  
  import java.io.Reader;
  import java.util.Arrays;
  import java.util.Set;
  
  
  /**
   * An {@link Analyzer} that tokenizes text with {@link CJKTokenizer} and
   * filters with {@link StopFilter}
   *
   */
  public final class CJKAnalyzer extends StopwordAnalyzerBase {
    //~ Static fields/initializers ---------------------------------------------
  
    /**
     * An array containing some common English words that are not usually
     * useful for searching and some double-byte interpunctions.
     * @deprecated use {@link #getDefaultStopSet()} instead
     */
    @Deprecated
    public final static String[] STOP_WORDS = {
      "a", "and", "are", "as", "at", "be",
      "but", "by", "for", "if", "in",
      "into", "is", "it", "no", "not",
      "of", "on", "or", "s", "such", "t",
      "that", "the", "their", "then",
      "there", "these", "they", "this",
      "to", "was", "will", "with", "",
      "www"
    };
  
    //~ Instance fields --------------------------------------------------------
  
    /**
     * Returns an unmodifiable instance of the default stop-words set.
     * @return an unmodifiable instance of the default stop-words set.
     */
    public static Set<?> getDefaultStopSet(){
      return DefaultSetHolder.DEFAULT_STOP_SET;
    }
    
    private static class DefaultSetHolder {
      static final Set<?> DEFAULT_STOP_SET = CharArraySet
          .unmodifiableSet(new CharArraySet(Version.LUCENE_CURRENT, Arrays.asList(STOP_WORDS),
              false));
    }
  
    //~ Constructors -----------------------------------------------------------
  
    /**
     * Builds an analyzer which removes words in {@link #getDefaultStopSet()}.
     */
    public CJKAnalyzer(Version matchVersion) {
      this(matchVersion, DefaultSetHolder.DEFAULT_STOP_SET);
    }
    
    /**
     * Builds an analyzer with the given stop words
     * 
     * @param matchVersion
     *          lucene compatibility version
     * @param stopwords
     *          a stopword set
     */
    public CJKAnalyzer(Version matchVersion, Set<?> stopwords){
      super(matchVersion, stopwords);
    }
  
    /**
     * Builds an analyzer which removes words in the provided array.
     *
     * @param stopWords stop word array
     * @deprecated use {@link #CJKAnalyzer(Version, Set)} instead
     */
    @Deprecated
    public CJKAnalyzer(Version matchVersion, String... stopWords) {
      super(matchVersion, StopFilter.makeStopSet(matchVersion, stopWords));
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override
    protected TokenStreamComponents createComponents(String fieldName,
        Reader reader) {
      final Tokenizer source = new CJKTokenizer(reader);
      return new TokenStreamComponents(source, new StopFilter(matchVersion, source, stopwords));
    }
  }
  