org.apache.lucene.analysis.cn.smart

Class SmartChineseAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.cn.smart.SmartChineseAnalyzer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class SmartChineseAnalyzer
extends Analyzer

SmartChineseAnalyzer is an analyzer for Chinese or mixed Chinese-English text. The analyzer uses probabilistic knowledge to find the optimal word segmentation for Simplified Chinese text. The text is first broken into sentences, then each sentence is segmented into words.

Segmentation is based upon the Hidden Markov Model. A large training corpus was used to calculate Chinese word frequency probability.

This analyzer requires a dictionary to provide statistical data. SmartChineseAnalyzer has an included dictionary out-of-box.

The included dictionary data is from ICTCLAS1.0. Thanks to ICTCLAS for their hard work, and for contributing the data under the Apache 2 License!

Since:

3.1

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.analysis.Analyzer

Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents

Field Summary

Fields inherited from class org.apache.lucene.analysis.Analyzer

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor and Description
SmartChineseAnalyzer() Create a new SmartChineseAnalyzer, using the default stopword list.
SmartChineseAnalyzer(boolean useDefaultStopWords) Create a new SmartChineseAnalyzer, optionally using the default stopword list.
SmartChineseAnalyzer(CharArraySet stopWords) Create a new SmartChineseAnalyzer, using the provided Set of stopwords.

Method Summary

Modifier and Type	Method and Description
Analyzer.TokenStreamComponents	createComponents(String fieldName)
static CharArraySet	getDefaultStopSet() Returns an unmodifiable instance of the default stop-words set.
protected TokenStream	normalize(String fieldName, TokenStream in)

Methods inherited from class org.apache.lucene.analysis.Analyzer

attributeFactory, close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, getVersion, initReader, initReaderForNormalization, normalize, setVersion, tokenStream, tokenStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SmartChineseAnalyzer

public SmartChineseAnalyzer()

Create a new SmartChineseAnalyzer, using the default stopword list.

SmartChineseAnalyzer

public SmartChineseAnalyzer(boolean useDefaultStopWords)

Create a new SmartChineseAnalyzer, optionally using the default stopword list.

The included default stopword list is simply a list of punctuation. If you do not use this list, punctuation will not be removed from the text!

Parameters:

useDefaultStopWords - true to use the default stopword list.

SmartChineseAnalyzer

public SmartChineseAnalyzer(CharArraySet stopWords)

Create a new SmartChineseAnalyzer, using the provided Set of stopwords.

Note: the set should include punctuation, unless you want to index punctuation!

Parameters:

stopWords - Set of stopwords to use.

Method Detail

getDefaultStopSet

public static CharArraySet getDefaultStopSet()

Returns an unmodifiable instance of the default stop-words set.

Returns:

an unmodifiable instance of the default stop-words set.

createComponents

public Analyzer.TokenStreamComponents createComponents(String fieldName)

Specified by:

createComponents in class Analyzer

normalize

protected TokenStream normalize(String fieldName,
                                TokenStream in)

Overrides:

normalize in class Analyzer