Package org.apache.tika.langdetect.tika

Class TikaLanguageDetector

java.lang.Object

org.apache.tika.language.detect.LanguageDetector

org.apache.tika.langdetect.tika.TikaLanguageDetector

public class TikaLanguageDetector
extends LanguageDetector

This is Tika's original legacy, homegrown language detector. As it is currently implemented, it computes vector distance of trigrams between input string and language models.

Because it works only on trigrams, it is not suitable for short texts.

There are better performing language detectors. This module is still here in the hopes that we'll get around to improving it, because it is elegant and could be fairly trivially improved.

Field Summary

Fields inherited from class org.apache.tika.language.detect.LanguageDetector

mixedLanguages, shortText

Constructor Summary

Constructors

Constructor	Description
TikaLanguageDetector()

Method Summary

Modifier and Type	Method	Description
void	addText(char[] cbuf, int off, int len)	Add statistics about this text for the current document.
List<LanguageResult>	detectAll()	Detect languages based on previously submitted text (via addText calls).
boolean	hasModel(String language)	Provide information about whether a model exists for a specific language.
LanguageDetector	loadModels()	Load (or re-load) all available language models.
LanguageDetector	loadModels(Set<String> languages)	Load (or re-load) the models specified in .
void	reset()	Reset statistics about the current document being processed
LanguageDetector	setPriors(Map<String,Float> languageProbabilities)	not supported

Methods inherited from class org.apache.tika.language.detect.LanguageDetector

addText, detect, detect, detectAll, getDefaultLanguageDetector, getLanguageDetectors, getLanguageDetectors, hasEnoughText, isMixedLanguages, isShortText, setMixedLanguages, setShortText

Methods inherited from class java.lang.Object

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

Constructor Detail

TikaLanguageDetector

public TikaLanguageDetector()

Method Detail

loadModels

public LanguageDetector loadModels()
                            throws IOException

Description copied from class: LanguageDetector

Load (or re-load) all available language models. This must be called after any settings that would impact the models being loaded (e.g. mixed language/short text), but before any of the document processing routines (below) are called. Note that it only needs to be called once.

Specified by:

loadModels in class LanguageDetector

Returns:

this

Throws:

IOException

loadModels

public LanguageDetector loadModels(Set<String> languages)
                            throws IOException

Description copied from class: LanguageDetector

Load (or re-load) the models specified in . These use the ISO 639-1 names, with an optional "-" for more specific specification (e.g. "zh-CN" for Chinese in China).

Specified by:

loadModels in class LanguageDetector

Parameters:

languages - list of target languages.

Returns:

this

Throws:

IOException

hasModel

public boolean hasModel(String language)

Description copied from class: LanguageDetector

Provide information about whether a model exists for a specific language.

Specified by:

hasModel in class LanguageDetector

Parameters:

language - ISO 639-1 name for language

Returns:

true if a model for this language exists.

setPriors

public LanguageDetector setPriors(Map<String,Float> languageProbabilities)
                           throws IOException

not supported

Specified by:

setPriors in class LanguageDetector

Parameters:

languageProbabilities - Map from language to probability

Returns:

Throws:

IOException

reset

public void reset()

Description copied from class: LanguageDetector

Reset statistics about the current document being processed

Specified by:

reset in class LanguageDetector

addText

public void addText(char[] cbuf,
                    int off,
                    int len)

Description copied from class: LanguageDetector

Add statistics about this text for the current document. Note that we assume an implicit word break exists before/after each of these runs of text.

Specified by:

addText in class LanguageDetector

Parameters:

cbuf - Character buffer

off - Offset into cbuf to first character in the run of text

len - Number of characters in the run of text.

detectAll

public List<LanguageResult> detectAll()

Description copied from class: LanguageDetector

Detect languages based on previously submitted text (via addText calls).

Specified by:

detectAll in class LanguageDetector

Returns:

list of all possible languages with at least medium confidence, sorted by confidence from highest to lowest. There will always be at least one result, which might have a confidence of NONE.