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

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!

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

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
static CharArraySet	getDefaultStopSet() Returns an unmodifiable instance of the default stop-words set.
TokenStream	reusableTokenStream(String fieldName, Reader reader) Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method.
TokenStream	tokenStream(String fieldName, Reader reader) Creates a TokenStream which tokenizes all the text in the provided Reader.

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

close, getOffsetGap, getPositionIncrementGap, getPreviousTokenStream, setPreviousTokenStream

Methods inherited from class java.lang.Object

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

Constructor Detail

SmartChineseAnalyzer

public SmartChineseAnalyzer(Version matchVersion)

Create a new SmartChineseAnalyzer, using the default stopword list.

SmartChineseAnalyzer

public SmartChineseAnalyzer(Version matchVersion,
                    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(Version matchVersion,
                    Set 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.

tokenStream

public TokenStream tokenStream(String fieldName,
                      Reader reader)

Description copied from class: Analyzer

Creates a TokenStream which tokenizes all the text in the provided Reader. Must be able to handle null field name for backward compatibility.

Specified by:

tokenStream in class Analyzer

reusableTokenStream

public TokenStream reusableTokenStream(String fieldName,
                              Reader reader)
                                throws IOException

Description copied from class: Analyzer

Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method. Callers that do not need to use more than one TokenStream at the same time from this analyzer should use this method for better performance.

Overrides:

reusableTokenStream in class Analyzer

Throws:

IOException