Cara umum untuk menghitung kemiripan antara dua string dengan cara 0% -100% , seperti yang digunakan di banyak pustaka, adalah mengukur berapa banyak (dalam%) Anda harus mengubah string yang lebih panjang untuk mengubahnya menjadi lebih pendek:
/**
* Calculates the similarity (a number within 0 and 1) between two strings.
*/
public static double similarity(String s1, String s2) {
String longer = s1, shorter = s2;
if (s1.length() < s2.length()) { // longer should always have greater length
longer = s2; shorter = s1;
}
int longerLength = longer.length();
if (longerLength == 0) { return 1.0; /* both strings are zero length */ }
return (longerLength - editDistance(longer, shorter)) / (double) longerLength;
}
// you can use StringUtils.getLevenshteinDistance() as the editDistance() function
// full copy-paste working code is below
Menghitung editDistance():
The editDistance()fungsi di atas diharapkan untuk menghitung mengedit jarak antara dua string. Ada beberapa implementasi untuk langkah ini, masing-masing mungkin lebih sesuai dengan skenario tertentu. Yang paling umum adalah algoritma jarak Levenshtein dan kami akan menggunakannya dalam contoh di bawah ini (untuk string yang sangat besar, algoritma lain cenderung berkinerja lebih baik).
Berikut dua opsi untuk menghitung jarak edit:
Contoh kerja:
Lihat demo online di sini.
public class StringSimilarity {
/**
* Calculates the similarity (a number within 0 and 1) between two strings.
*/
public static double similarity(String s1, String s2) {
String longer = s1, shorter = s2;
if (s1.length() < s2.length()) { // longer should always have greater length
longer = s2; shorter = s1;
}
int longerLength = longer.length();
if (longerLength == 0) { return 1.0; /* both strings are zero length */ }
/* // If you have Apache Commons Text, you can use it to calculate the edit distance:
LevenshteinDistance levenshteinDistance = new LevenshteinDistance();
return (longerLength - levenshteinDistance.apply(longer, shorter)) / (double) longerLength; */
return (longerLength - editDistance(longer, shorter)) / (double) longerLength;
}
// Example implementation of the Levenshtein Edit Distance
// See http://rosettacode.org/wiki/Levenshtein_distance#Java
public static int editDistance(String s1, String s2) {
s1 = s1.toLowerCase();
s2 = s2.toLowerCase();
int[] costs = new int[s2.length() + 1];
for (int i = 0; i <= s1.length(); i++) {
int lastValue = i;
for (int j = 0; j <= s2.length(); j++) {
if (i == 0)
costs[j] = j;
else {
if (j > 0) {
int newValue = costs[j - 1];
if (s1.charAt(i - 1) != s2.charAt(j - 1))
newValue = Math.min(Math.min(newValue, lastValue),
costs[j]) + 1;
costs[j - 1] = lastValue;
lastValue = newValue;
}
}
}
if (i > 0)
costs[s2.length()] = lastValue;
}
return costs[s2.length()];
}
public static void printSimilarity(String s, String t) {
System.out.println(String.format(
"%.3f is the similarity between \"%s\" and \"%s\"", similarity(s, t), s, t));
}
public static void main(String[] args) {
printSimilarity("", "");
printSimilarity("1234567890", "1");
printSimilarity("1234567890", "123");
printSimilarity("1234567890", "1234567");
printSimilarity("1234567890", "1234567890");
printSimilarity("1234567890", "1234567980");
printSimilarity("47/2010", "472010");
printSimilarity("47/2010", "472011");
printSimilarity("47/2010", "AB.CDEF");
printSimilarity("47/2010", "4B.CDEFG");
printSimilarity("47/2010", "AB.CDEFG");
printSimilarity("The quick fox jumped", "The fox jumped");
printSimilarity("The quick fox jumped", "The fox");
printSimilarity("kitten", "sitting");
}
}
Keluaran:
1.000 is the similarity between "" and ""
0.100 is the similarity between "1234567890" and "1"
0.300 is the similarity between "1234567890" and "123"
0.700 is the similarity between "1234567890" and "1234567"
1.000 is the similarity between "1234567890" and "1234567890"
0.800 is the similarity between "1234567890" and "1234567980"
0.857 is the similarity between "47/2010" and "472010"
0.714 is the similarity between "47/2010" and "472011"
0.000 is the similarity between "47/2010" and "AB.CDEF"
0.125 is the similarity between "47/2010" and "4B.CDEFG"
0.000 is the similarity between "47/2010" and "AB.CDEFG"
0.700 is the similarity between "The quick fox jumped" and "The fox jumped"
0.350 is the similarity between "The quick fox jumped" and "The fox"
0.571 is the similarity between "kitten" and "sitting"