SpellChecker (Lucene 2.9.4 API)

java.lang.Object
- org.apache.lucene.search.spell.SpellChecker

public class SpellChecker
extends java.lang.Object

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

Example Usage:

  SpellChecker spellchecker = new SpellChecker(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);

Version:: 1.0

Field Summary

Fields
Modifier and Type Field and Description

static java.lang.String F_WORD
Field name for each word in the ngram index.

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`F_WORD` Field name for each word in the ngram index.

Constructor Summary

Constructors
Constructor and Description
`SpellChecker(Directory spellIndex)` Use the given directory as a spell checker index with a `LevensteinDistance` as the default `StringDistance`.
`SpellChecker(Directory spellIndex, StringDistance sd)` Use the given directory as a spell checker index.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clearIndex()` Removes all terms from the spell check index.
`void`	`close()` Close the IndexSearcher used by this SpellChecker
`boolean`	`exist(java.lang.String word)` Check whether the word exists in the index.
`StringDistance`	`getStringDistance()` Returns the `StringDistance` instance used by this `SpellChecker` instance.
`void`	`indexDictionary(Dictionary dict)` Indexes the data from the given `Dictionary`.
`void`	`indexDictionary(Dictionary dict, int mergeFactor, int ramMB)` Indexes the data from the given `Dictionary`.
`void`	`setAccuracy(float minScore)` Sets the accuracy 0 < minScore < 1; default 0.5
`void`	`setSpellIndex(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(StringDistance sd)` Sets the `StringDistance` implementation for this `SpellChecker` instance.
`java.lang.String[]`	`suggestSimilar(java.lang.String word, int numSug)` Suggest similar words.
`java.lang.String[]`	`suggestSimilar(java.lang.String word, int numSug, IndexReader ir, java.lang.String field, boolean morePopular)` Suggest similar words (optionally restricted to a field of an index).

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 java.lang.String F_WORD
```
    Field name for each word in the ngram index.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SpellChecker
```
public SpellChecker(Directory spellIndex,
                    StringDistance sd)
             throws java.io.IOException
```
    Use the given directory as a spell checker index. The directory is created if it doesn't exist yet.
    
    Parameters:
    
    spellIndex - the spell index directory
    
    sd - the StringDistance measurement to use
    
    Throws:
    
    java.io.IOException - if Spellchecker can not open the directory
  - SpellChecker
```
public SpellChecker(Directory spellIndex)
             throws java.io.IOException
```
    Use the given directory as a spell checker index with a LevensteinDistance as the default StringDistance. The directory is created if it doesn't exist yet.
    
    Parameters:
    
    spellIndex - the spell index directory
    
    Throws:
    
    java.io.IOException - if spellchecker can not open the directory
- Method Detail
  - setSpellIndex
```
public void setSpellIndex(Directory spellIndexDir)
                   throws java.io.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:
    
    AlreadyClosedException - if the Spellchecker is already closed
    
    java.io.IOException - if spellchecker can not open the directory
  - setStringDistance
```
public void setStringDistance(StringDistance sd)
```
    Sets the StringDistance implementation for this SpellChecker instance.
    
    Parameters:
    
    sd - the StringDistance implementation for this SpellChecker instance
  - getStringDistance
```
public 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 java.lang.String[] suggestSimilar(java.lang.String word,
                                         int numSug)
                                  throws java.io.IOException
```
    Suggest similar words.
    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
    
    Returns:
    
    String[]
    
    Throws:
    
    java.io.IOException - if the underlying index throws an IOException
    
    AlreadyClosedException - if the Spellchecker is already closed
  - suggestSimilar
```
public java.lang.String[] suggestSimilar(java.lang.String word,
                                         int numSug,
                                         IndexReader ir,
                                         java.lang.String field,
                                         boolean morePopular)
                                  throws java.io.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)
    
    field - the field of the user index: if field is not null, the suggested words are restricted to the words present in this field.
    
    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)
    
    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:
    
    java.io.IOException - if the underlying index throws an IOException
    
    AlreadyClosedException - if the Spellchecker is already closed
  - clearIndex
```
public void clearIndex()
                throws java.io.IOException
```
    Removes all terms from the spell check index.
    
    Throws:
    
    java.io.IOException
    
    AlreadyClosedException - if the Spellchecker is already closed
  - exist
```
public boolean exist(java.lang.String word)
              throws java.io.IOException
```
    Check whether the word exists in the index.
    
    Parameters:
    
    word -
    
    Returns:
    
    true if the word exists in the index
    
    Throws:
    
    java.io.IOException
    
    AlreadyClosedException - if the Spellchecker is already closed
  - indexDictionary
```
public void indexDictionary(Dictionary dict,
                            int mergeFactor,
                            int ramMB)
                     throws java.io.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:
    
    AlreadyClosedException - if the Spellchecker is already closed
    
    java.io.IOException
  - indexDictionary
```
public void indexDictionary(Dictionary dict)
                     throws java.io.IOException
```
    Indexes the data from the given Dictionary.
    
    Parameters:
    
    dict - the dictionary to index
    
    Throws:
    
    java.io.IOException
  - close
```
public void close()
           throws java.io.IOException
```
    Close the IndexSearcher used by this SpellChecker
    
    Throws:
    
    java.io.IOException - if the close operation causes an IOException
    
    AlreadyClosedException - if the SpellChecker is already closed

Class SpellChecker

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

F_WORD

Constructor Detail

SpellChecker

SpellChecker

Method Detail

setSpellIndex

setStringDistance

getStringDistance

setAccuracy

suggestSimilar

suggestSimilar

clearIndex

exist

indexDictionary

indexDictionary

close