standardanalyzer.cs

Lucene.Net 版本源码 测试通过

/*
 * 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.
 */

using System;
using Lucene.Net.Analysis;

namespace Lucene.Net.Analysis.Standard
{
	
    /// <summary> Filters {@link StandardTokenizer} with {@link StandardFilter}, {@link
    /// LowerCaseFilter} and {@link StopFilter}, using a list of English stop words.
    /// 
    /// </summary>
    /// <version>  $Id: StandardAnalyzer.java 219090 2005-07-14 20:36:28Z dnaber $
    /// </version>
    public class StandardAnalyzer : Analyzer
    {
        private System.Collections.Hashtable stopSet;
		
        /// <summary>An array containing some common English words that are usually not
        /// useful for searching. 
        /// </summary>
        public static readonly System.String[] STOP_WORDS;
		
        /// <summary>Builds an analyzer with the default stop words ({@link #STOP_WORDS}). </summary>
        public StandardAnalyzer() : this(STOP_WORDS)
        {
        }
		
        /// <summary>Builds an analyzer with the given stop words. </summary>
        public StandardAnalyzer(System.Collections.Hashtable stopWords)
        {
            stopSet = stopWords;
        }
		
        /// <summary>Builds an analyzer with the given stop words. </summary>
        public StandardAnalyzer(System.String[] stopWords)
        {
            stopSet = StopFilter.MakeStopSet(stopWords);
        }
		
        /// <summary>Builds an analyzer with the stop words from the given file.</summary>
        /// <seealso cref="WordlistLoader.GetWordSet(File)">
        /// </seealso>
        public StandardAnalyzer(System.IO.FileInfo stopwords)
        {
            stopSet = WordlistLoader.GetWordSet(stopwords);
        }
		
        /// <summary>Builds an analyzer with the stop words from the given reader.</summary>
        /// <seealso cref="WordlistLoader.GetWordSet(Reader)">
        /// </seealso>
        public StandardAnalyzer(System.IO.TextReader stopwords)
        {
            stopSet = WordlistLoader.GetWordSet(stopwords);
        }
		
        /// <summary>Constructs a {@link StandardTokenizer} filtered by a {@link
        /// StandardFilter}, a {@link LowerCaseFilter} and a {@link StopFilter}. 
        /// </summary>
        public override TokenStream TokenStream(System.String fieldName, System.IO.TextReader reader)
        {
            TokenStream result = new StandardTokenizer(reader);
            result = new StandardFilter(result);
            result = new LowerCaseFilter(result);
            result = new StopFilter(result, stopSet);
            return result;
        }
        static StandardAnalyzer()
        {
            STOP_WORDS = StopAnalyzer.ENGLISH_STOP_WORDS;
        }
    }
}