edu.northwestern.at.utils.spellcheck

Class SimpleMindedSpellingChecker

java.lang.Object

edu.northwestern.at.utils.spellcheck.SimpleMindedSpellingChecker

All Implemented Interfaces:

SpellingChecker

public class SimpleMindedSpellingChecker
extends java.lang.Object
implements SpellingChecker

SimpleMindedSpellingChecker -- A very simple minded spelling checker.

Implements a very simple minded spelling checker using HashMaps to hold the dictionaries. The dictionaries are read as combined word lists and metaphone codes from text files into two hashmaps. One hashmap contains each word as a key and has the metaphone code for that word as a value. The second hashmap uses the metaphone values as keys and the list of words mapping to that metaphone as values. This allows presentation of suggested spellings for misspelled words. The list of suggestions may optionally be pruned by using a measure of the Levenstein distance between the original misspelling and each suggested spelling.

Words beginning with a digit are assumed to be numbers and therefore spelled correctly.

When creating a list of suggested replacements for a misspelled word, the first letter of the suggestions is capitalized if the first letter of the original misspelled word is capitalized.

This class is not intended for production use because of the time needed to load and save dictionaries and the amount of memory used to hold the dictionaries in memory. This class serves as a reference implementation for the SpellingChecker interface as well as a testbed for applications needing a spelling checker during development.

Constructor Summary

Constructors

Constructor and Description
SimpleMindedSpellingChecker() Create spelling checked without loading any dictionaries.
SimpleMindedSpellingChecker(SpellingDictionary globalDictionary) Create spelling checker specifying global dictionary.
SimpleMindedSpellingChecker(SpellingDictionary globalDictionary, SpellingDictionary localDictionary) Create spelling checker specifying global and local dictionaries.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addWordToGlobalDictionary(java.lang.String word) Add a word to the global dictionary.
boolean	addWordToIgnoreList(java.lang.String word) Add word to ignore list.
boolean	addWordToLocalDictionary(java.lang.String word) Add a word to the local dictionary.
boolean	checkSpelling(java.lang.String word) Check spelling of word.
void	emptyIgnoreList() Empties the ignore list.
java.lang.String[]	suggest(java.lang.String word) Suggest alternative words for misspelled item.
java.lang.String[]	suggest(java.lang.String word, boolean prune) Suggest alternative words for misspelled item.
void	useGlobalDictionary(SpellingDictionary dictionary) Select global dictionary to use to check spelling.
void	useLocalDictionary(SpellingDictionary dictionary) Select local dictionary to use to check spelling.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleMindedSpellingChecker

public SimpleMindedSpellingChecker(SpellingDictionary globalDictionary,
                           SpellingDictionary localDictionary)

Create spelling checker specifying global and local dictionaries.

SimpleMindedSpellingChecker

public SimpleMindedSpellingChecker(SpellingDictionary globalDictionary)

Create spelling checker specifying global dictionary.

SimpleMindedSpellingChecker

public SimpleMindedSpellingChecker()

Create spelling checked without loading any dictionaries.

Method Detail

useGlobalDictionary

public void useGlobalDictionary(SpellingDictionary dictionary)

Select global dictionary to use to check spelling.

Specified by:

useGlobalDictionary in interface SpellingChecker

Parameters:

dictionary - Identifies dictionary. The dictionary class must implement the SpellingDictionary interface.

The global dictionary is usually shared among many users. Typically it is created by a system administrator as a shareable resource.

useLocalDictionary

public void useLocalDictionary(SpellingDictionary dictionary)

Select local dictionary to use to check spelling.

Specified by:

useLocalDictionary in interface SpellingChecker

Parameters:

dictionary - The dictionary to use. If the name is null, no local dictionary is used. The dictionary class must implement the SpellingDictionary interface.

The local dictionary is usually limited to access by a single individual. The local dictionary generally contains words added by an individual while checking the spelling of one or more documents.

checkSpelling

public boolean checkSpelling(java.lang.String word)

Check spelling of word.

Specified by:

checkSpelling in interface SpellingChecker

Parameters:

word - The word whose spelling should be checked.

Returns:

True if the word was found in the global or local dictionaries.

suggest

public java.lang.String[] suggest(java.lang.String word,
                         boolean prune)

Suggest alternative words for misspelled item.

Parameters:

word - The misspelled word for which possible alternatives are desired.

prune - True to prune suggestions using Levenstein distance.

Returns:

Sorted array of correctly spelled words which are similar in some sense to the misspelled word.

The suggested words are typically words which are similar in sound or spelling to the misspelled word. If the misspelled word begins with a capital letter, the suggestions are also capitalized to match.

suggest

public java.lang.String[] suggest(java.lang.String word)

Suggest alternative words for misspelled item.

Specified by:

suggest in interface SpellingChecker

Parameters:

word - The misspelled word for which possible alternatives are desired.

The suggested words are typically words which are similar in sound or spelling to the misspelled word.

Returns:

String array of correctly spelled words which are similar in some sense to the misspelled word.

The suggested words are typically words which are similar in sound or spelling to the misspelled word. For English, an implementation might return all words with the same soundex or metaphone code as the misspelled word.

addWordToLocalDictionary

public boolean addWordToLocalDictionary(java.lang.String word)

Add a word to the local dictionary.

Specified by:

addWordToLocalDictionary in interface SpellingChecker

Parameters:

word - The word to add to the local dictionary.

Returns:

True if word added successfully.

addWordToGlobalDictionary

public boolean addWordToGlobalDictionary(java.lang.String word)

Add a word to the global dictionary.

Specified by:

addWordToGlobalDictionary in interface SpellingChecker

Parameters:

word - The word to add to the global dictionary.

Returns:

True if word added successfully.

Typically this function is retricted to system administrators.

addWordToIgnoreList

public boolean addWordToIgnoreList(java.lang.String word)

Add word to ignore list.

Specified by:

addWordToIgnoreList in interface SpellingChecker

Parameters:

word - Word to ignore.

Returns:

True if word successfully added to ignore list.

The ignore list contains words which an individual marks as ignorable while checking the spelling of one of more documents. The ignore list is transient. If an ignored word is to persist across multiple spelling check sessions, the word should be added to the local dictionary.

emptyIgnoreList

public void emptyIgnoreList()

Empties the ignore list.

Removes all words from the ignore list. Typically this is invoked at the start of a spelling checker session for a new document.

Specified by:

emptyIgnoreList in interface SpellingChecker