# Package org.apache.lucene.analysis.cjk

package org.apache.lucene.analysis.cjk
Analyzer for Chinese, Japanese, and Korean, which indexes bigrams. This analyzer generates bigram terms, which are overlapping groups of two adjacent Han, Hiragana, Katakana, or Hangul characters.

Three analyzers are provided for Chinese, each of which treats Chinese text in a different way.

- ChineseAnalyzer (in the analyzers/cn package): Index unigrams (individual Chinese characters) as a token.
- CJKAnalyzer (in this package): Index bigrams (overlapping groups of two adjacent Chinese characters) as tokens.
- SmartChineseAnalyzer (in the analyzers/smartcn package): Index words (attempt to segment Chinese text into words) as tokens.

Example phrase： "我是中国人"

1. ChineseAnalyzer: 我－是－中－国－人
2. CJKAnalyzer: 我是－是中－中国－国人
3. SmartChineseAnalyzer: 我－是－中国－人

- Classes
  Class
  Description
  CJKAnalyzer
  An `Analyzer` that tokenizes text with `StandardTokenizer`, normalizes content with `CJKWidthFilter`, folds case with `LowerCaseFilter`, forms bigrams of CJK with `CJKBigramFilter`, and filters stopwords with `StopFilter`
  CJKBigramFilter
  Forms bigrams of CJK terms that are generated from StandardTokenizer or ICUTokenizer.
  CJKBigramFilterFactory
  Factory for `CJKBigramFilter`.
  CJKWidthCharFilter
  A `CharFilter` that normalizes CJK width differences: Folds fullwidth ASCII variants into the equivalent basic latin Folds halfwidth Katakana variants into the equivalent kana
  CJKWidthCharFilterFactory
  Factory for `CJKWidthCharFilter`.
  CJKWidthFilter
  A `TokenFilter` that normalizes CJK width differences: Folds fullwidth ASCII variants into the equivalent basic latin Folds halfwidth Katakana variants into the equivalent kana
  CJKWidthFilterFactory
  Factory for `CJKWidthFilter`.