cjkanalyzer.java

「我是中國人」

package org.apache.lucene.analysis.cjk;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2004 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Lucene" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache Lucene", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * $Id: CJKAnalyzer.java,v 1.5 2004/10/17 11:41:41 dnaber Exp $
 */

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.TokenStream;

import java.io.Reader;
import java.util.Set;


/**
 * Filters CJKTokenizer with StopFilter.
 *
 * @author Che, Dong
 */
public class CJKAnalyzer extends Analyzer {
  //~ Static fields/initializers ---------------------------------------------

  /**
   * An array containing some common English words that are not usually
   * useful for searching. and some double-byte interpunctions.....
   */
  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 --------------------------------------------------------

  /**
   * stop word list
   */
  private Set stopTable;

  //~ Constructors -----------------------------------------------------------

  /**
   * Builds an analyzer which removes words in {@link #STOP_WORDS}.
   */
  public CJKAnalyzer() {
    stopTable = StopFilter.makeStopSet(STOP_WORDS);
  }

  /**
   * Builds an analyzer which removes words in the provided array.
   *
   * @param stopWords stop word array
   */
  public CJKAnalyzer(String[] stopWords) {
    stopTable = StopFilter.makeStopSet(stopWords);
  }

  //~ Methods ----------------------------------------------------------------

  /**
   * get token stream from input
   *
   * @param fieldName lucene field name
   * @param reader    input reader
   * @return TokenStream
   */
  public final TokenStream tokenStream(String fieldName, Reader reader) {
    return new StopFilter(new CJKTokenizer(reader), stopTable);
  }
}