com.tplan.robot.util

Class FuzzyStringComparator

java.lang.Object

com.tplan.robot.util.FuzzyStringComparator

public class FuzzyStringComparator
extends Object

Utility methods dealing with fuzzy string matching.

T-Plan Robot Enterprise, (C) 2009-2022 T-Plan Limited. All rights reserved.

Constructor Summary

Constructors

Constructor and Description
FuzzyStringComparator()

Method Summary

Modifier and Type	Method and Description
static int	distance(String s, String t) Compute the Levenshtein distance of two strings.
static List<TextSearchResult>	findAll(Pattern p, String text, boolean greedy) Find all locations in the text that match the provided regular expression.
static List<TextSearchResult>	findAll(String regexp, String text, boolean greedy) Find all locations in the text that match the provided regular expression.
static List<TextSearchResult>	findAll(String pattern, String text, int distance) Search the text for all substrings matching the given pattern with a Levenshtein distance up to the specified limit.
static int	indexOf(String pattern, String text, int distance, StringBuffer outBuf) Search text for a substring with a Levenshtein distance up to the specified limit.
static float	relativeDistance(String s, String t) Compute relative Levenshtein distance of two strings.

Methods inherited from class java.lang.Object

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

Constructor Detail

FuzzyStringComparator

public FuzzyStringComparator()

Method Detail

distance

public static int distance(String s,
                           String t)

Compute the Levenshtein distance of two strings.

Parameters:

s - one string.

t - another string to be compared to the first one.

Returns:

Levenshtein distance. It is defined as the minimum number of edits needed to transform one string into the other, with the allowable edit operations being insertion, deletion, or substitution of a single character.

relativeDistance

public static float relativeDistance(String s,
                                     String t)

Compute relative Levenshtein distance of two strings. It is the standard distance multiplied by the length of the longer string.

Parameters:

s - one string.

t - another string to be compared to the first one.

Returns:

Levenshtein distance relative to the string length (the longer of the two lengths).

indexOf

public static int indexOf(String pattern,
                          String text,
                          int distance,
                          StringBuffer outBuf)

Search text for a substring with a Levenshtein distance up to the specified limit. If the distance is equal to zero, the method behaves the same way as the standard String.indexOf() method.

Parameters:

pattern - a substring to search for. Must not be null.

text - text to search. Must not be null.

distance - maximum allowed text distance (difference).

outBuf - optional output buffer to copy the matching string to.

Returns:

index of the match or -1 if not found.

findAll

public static List<TextSearchResult> findAll(String pattern,
                                             String text,
                                             int distance)

Search the text for all substrings matching the given pattern with a Levenshtein distance up to the specified limit. The resulting list is by default sorted just by the match index. To get a list sorted from the best match (the lowest distance) to the worst one and by the index where the distances equal call Collections.sort(java.util.List) on the resulting list..

Parameters:

pattern - a substring to search for. Must not be null.

text - text to search. Must not be null.

distance - maximum allowed text distance (difference).

Returns:

the list of the matching strings and their locations.

findAll

public static List<TextSearchResult> findAll(String regexp,
                                             String text,
                                             boolean greedy)

Find all locations in the text that match the provided regular expression.

Parameters:

regexp - a regular expression.

text - the text to search.

greedy - true will enable overlapping (one match may intersect with another one).

Returns:

the list of matches.

findAll

public static List<TextSearchResult> findAll(Pattern p,
                                             String text,
                                             boolean greedy)

Find all locations in the text that match the provided regular expression.

Parameters:

p - a regular expression.

text - the text to search.

greedy - true will enable overlapping (one match may intersect with another one).

Returns:

the list of matches.