/*
 * 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.
 */
package org.apache.lucene.analysis.standard;


import java.io.IOException;
import java.io.Reader;

import org.apache.lucene.analysis.CharArraySet;
import org.apache.lucene.analysis.LowerCaseFilter;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.StopwordAnalyzerBase;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.WordlistLoader;

Filters StandardTokenizer with LowerCaseFilter and StopFilter, using a configurable list of stop words. 
Since:
3.1/**
 * Filters {@link StandardTokenizer} with {@link LowerCaseFilter} and
 * {@link StopFilter}, using a configurable list of stop words.
 *
 * @since 3.1
 */
public final class StandardAnalyzer extends StopwordAnalyzerBase {
  
  
Default maximum allowed token length /** Default maximum allowed token length */
  public static final int DEFAULT_MAX_TOKEN_LENGTH = 255;

  private int maxTokenLength = DEFAULT_MAX_TOKEN_LENGTH;

  
Builds an analyzer with the given stop words.
Params:
stopWords – stop words/** Builds an analyzer with the given stop words.
   * @param stopWords stop words */
  public StandardAnalyzer(CharArraySet stopWords) {
    super(stopWords);
  }

  
Builds an analyzer with no stop words.
/** Builds an analyzer with no stop words.
   */
  public StandardAnalyzer() {
    this(CharArraySet.EMPTY_SET);
  }

  
Builds an analyzer with the stop words from the given reader.
Params:
stopwords – Reader to read stop words from
See Also:
getWordSet.getWordSet(Reader)/** Builds an analyzer with the stop words from the given reader.
   * @see WordlistLoader#getWordSet(Reader)
   * @param stopwords Reader to read stop words from */
  public StandardAnalyzer(Reader stopwords) throws IOException {
    this(loadStopwordSet(stopwords));
  }

  
Set the max allowed token length. Tokens larger than this will be chopped up at this token length and emitted as multiple tokens. If you need to skip such large tokens, you could increase this max length, and then use LengthFilter to remove long tokens. The default is DEFAULT_MAX_TOKEN_LENGTH. /**
   * Set the max allowed token length.  Tokens larger than this will be chopped
   * up at this token length and emitted as multiple tokens.  If you need to
   * skip such large tokens, you could increase this max length, and then
   * use {@code LengthFilter} to remove long tokens.  The default is
   * {@link StandardAnalyzer#DEFAULT_MAX_TOKEN_LENGTH}.
   */
  public void setMaxTokenLength(int length) {
    maxTokenLength = length;
  }
    
  
Returns the current maximum token length
 @see #setMaxTokenLength /** Returns the current maximum token length
   * 
   *  @see #setMaxTokenLength */
  public int getMaxTokenLength() {
    return maxTokenLength;
  }

  @Override
  protected TokenStreamComponents createComponents(final String fieldName) {
    final StandardTokenizer src = new StandardTokenizer();
    src.setMaxTokenLength(maxTokenLength);
    TokenStream tok = new LowerCaseFilter(src);
    tok = new StopFilter(tok, stopwords);
    return new TokenStreamComponents(r -> {
      src.setMaxTokenLength(StandardAnalyzer.this.maxTokenLength);
      src.setReader(r);
    }, tok);
  }

  @Override
  protected TokenStream normalize(String fieldName, TokenStream in) {
    return new LowerCaseFilter(in);
  }
}