lucene/analysis/smartcn/src/java/org/apache/lucene/analysis/cn/smart/HMMChineseTokenizerFactory.java

/*
 * 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.cn.smart;

import java.util.Map;

import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.util.TokenizerFactory;
import org.apache.lucene.util.AttributeFactory;

/**
 * Factory for {@link HMMChineseTokenizer}
 * <p>
 * Note: this class will currently emit tokens for punctuation. So you should either add
 * a WordDelimiterFilter after to remove these (with concatenate off), or use the 
 * SmartChinese stoplist with a StopFilterFactory via:
 * <code>words="org/apache/lucene/analysis/cn/smart/stopwords.txt"</code>
 * @lucene.experimental
 *
 * @since 4.10.0
 * @lucene.spi {@value #NAME}
 */
public final class HMMChineseTokenizerFactory extends TokenizerFactory {

  /** SPI name */
  public static final String NAME = "hmmChinese";

  /** Creates a new HMMChineseTokenizerFactory */
  public HMMChineseTokenizerFactory(Map<String,String> args) {
    super(args);
    if (!args.isEmpty()) {
      throw new IllegalArgumentException("Unknown parameters: " + args);
    }
  }

  @Override
  public Tokenizer create(AttributeFactory factory) {
    return new HMMChineseTokenizer(factory);
  }
}