org.apache.lucene.search.spell

Class JahiaExtendedSpellChecker

java.lang.Object

org.apache.lucene.search.spell.JahiaExtendedSpellChecker

All Implemented Interfaces:

Closeable, AutoCloseable

public class JahiaExtendedSpellChecker
extends Object
implements Closeable

Jahia Spell Checker class (Main class)
(initially inspired by the David Spencer code).

The Jahia specific part is mainly to be able to create/maintain own dictionaries by site and language.

Example Usage:

  JahiaSpellChecker spellchecker = new JahiaSpellChecker(spellIndexDirectory);
  // To index a field of a user index:
  spellchecker.indexDictionary(new LuceneDictionary(my_lucene_reader, a_field));
  // To index a file containing words:
  spellchecker.indexDictionary(new PlainTextDictionary(new File("myfile.txt")));
  String[] suggestions = spellchecker.suggestSimilar("misspelt", 5);
 

Field Summary

Fields

Modifier and Type	Field and Description
static String	F_LANGUAGE
static String	F_SITE
static String	F_WORD Field name for each word in the ngram index.

Constructor Summary

Constructors

Constructor and Description
JahiaExtendedSpellChecker(org.apache.lucene.store.Directory spellIndex)
JahiaExtendedSpellChecker(org.apache.lucene.store.Directory spellIndex, org.apache.lucene.search.spell.StringDistance sd) Use the given directory as a spell checker index.

Method Summary

Modifier and Type	Method and Description
void	clearIndex() Removes all terms from the spell check index.
void	close()
boolean	exist(String word, String langCode, String site) Check whether the word exists in the index.
org.apache.lucene.search.spell.StringDistance	getStringDistance() Returns the StringDistance instance used by this SpellChecker instance.
void	indexDictionary(org.apache.lucene.search.spell.Dictionary dict, int mergeFactor, int ramMB, String site, String langCode) Indexes the data from the given Dictionary.
void	setAccuracy(float minScore) Sets the accuracy 0 < minScore < 1; default 0.5
void	setSpellIndex(org.apache.lucene.store.Directory spellIndexDir) Use a different index as the spell checker index or re-open the existing index if spellIndex is the same value as given in the constructor.
void	setStringDistance(org.apache.lucene.search.spell.StringDistance sd) Sets the StringDistance implementation for this SpellChecker instance.
String[]	suggestSimilar(String word, int numSug, org.apache.lucene.index.IndexReader ir, boolean morePopular, String[] sites, String language) Suggest similar words (optionally restricted to a field of an index).
String[]	suggestSimilar(String word, int numSug, org.apache.lucene.index.IndexReader ir, String field, boolean morePopular, String sites, String language) Deprecated.

Methods inherited from class java.lang.Object

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

Field Detail

F_WORD

public static final String F_WORD

Field name for each word in the ngram index.

See Also:

Constant Field Values

F_LANGUAGE

public static final String F_LANGUAGE

F_SITE

public static final String F_SITE

Constructor Detail

JahiaExtendedSpellChecker

public JahiaExtendedSpellChecker(org.apache.lucene.store.Directory spellIndex,
                                 org.apache.lucene.search.spell.StringDistance sd)
                          throws IOException

Use the given directory as a spell checker index. The directory is created if it doesn't exist yet.

Parameters:

spellIndex -

Throws:

IOException

JahiaExtendedSpellChecker

public JahiaExtendedSpellChecker(org.apache.lucene.store.Directory spellIndex)
                          throws IOException

Throws:

IOException

Method Detail

setSpellIndex

public void setSpellIndex(org.apache.lucene.store.Directory spellIndexDir)
                   throws IOException

Use a different index as the spell checker index or re-open the existing index if spellIndex is the same value as given in the constructor.

Parameters:

spellIndexDir - the spell directory to use

Throws:

org.apache.lucene.store.AlreadyClosedException - if the Spellchecker is already closed

IOException - if spellchecker can not open the directory

setStringDistance

public void setStringDistance(org.apache.lucene.search.spell.StringDistance sd)

Sets the StringDistance implementation for this SpellChecker instance.

Parameters:

sd - the StringDistance implementation for this SpellChecker instance

getStringDistance

public org.apache.lucene.search.spell.StringDistance getStringDistance()

Returns the StringDistance instance used by this SpellChecker instance.

Returns:

the StringDistance instance used by this SpellChecker instance.

setAccuracy

public void setAccuracy(float minScore)

Sets the accuracy 0 < minScore < 1; default 0.5

suggestSimilar

public String[] suggestSimilar(String word,
                               int numSug,
                               org.apache.lucene.index.IndexReader ir,
                               String field,
                               boolean morePopular,
                               String sites,
                               String language)
                        throws IOException

Deprecated.

Throws:

IOException

suggestSimilar

public String[] suggestSimilar(String word,
                               int numSug,
                               org.apache.lucene.index.IndexReader ir,
                               boolean morePopular,
                               String[] sites,
                               String language)
                        throws IOException

Suggest similar words (optionally restricted to a field of an index).

As the Lucene similarity that is used to fetch the most relevant n-grammed terms is not the same as the edit distance strategy used to calculate the best matching spell-checked word from the hits that Lucene found, one usually has to retrieve a couple of numSug's in order to get the true best match.

I.e. if numSug == 1, don't count on that suggestion being the best one. Thus, you should set this value to at least 5 for a good suggestion.

Parameters:

word - the word you want a spell check done on

numSug - the number of suggested words

ir - the indexReader of the user index (can be null see field param)

morePopular - return only the suggest words that are as frequent or more frequent than the searched word (only if restricted mode = (indexReader!=null and field!=null)

sites - an array of site keys to search in

language - the current languages, used for the search

Returns:

String[] the sorted list of the suggest words with these 2 criteria: first criteria: the edit distance, second criteria (only if restricted mode): the popularity of the suggest words in the field of the user index

Throws:

IOException - in case of index read error

clearIndex

public void clearIndex()
                throws IOException

Removes all terms from the spell check index.

Throws:

IOException

org.apache.lucene.store.AlreadyClosedException - if the Spellchecker is already closed

exist

public boolean exist(String word,
                     String langCode,
                     String site)
              throws IOException

Check whether the word exists in the index.

Parameters:

word -

Returns:

true iff the word exists in the index

Throws:

IOException

indexDictionary

public void indexDictionary(org.apache.lucene.search.spell.Dictionary dict,
                            int mergeFactor,
                            int ramMB,
                            String site,
                            String langCode)
                     throws IOException

Indexes the data from the given Dictionary.

Parameters:

dict - Dictionary to index

mergeFactor - mergeFactor to use when indexing

ramMB - the max amount or memory in MB to use

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException