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OptaPlanner solves planning problems.
This lightweight, embeddable planning engine implements powerful and scalable algorithms
to optimize business resource scheduling and planning.
This module contains the non-web examples which demonstrate how to use it in a normal Java application.
package org.optaplanner.examples.common.business;
import java.util.Comparator;
/**
* Sorts data like this: "data-1", "data-2", "data-3", "data-10", "data-20", "data-100", ...
*/
public class AlphaNumericStringComparator implements Comparator {
public int compare(String a, String b) {
char[] aChars = a.toCharArray();
char[] bChars = b.toCharArray();
int aIndex = 0;
int bIndex = 0;
while (true) {
if (aIndex >= aChars.length) {
if (bIndex >= bChars.length) {
return 0;
} else {
return -1;
}
} else if (bIndex >= bChars.length) {
return 1;
}
char aChar = aChars[aIndex];
char bChar = bChars[bIndex];
if (isDigit(aChar) && isDigit(bChar)) {
int aIndexTo = aIndex + 1;
while (aIndexTo < aChars.length && isDigit(aChars[aIndexTo])) {
aIndexTo++;
}
int bIndexTo = bIndex + 1;
while (bIndexTo < bChars.length && isDigit(bChars[bIndexTo])) {
bIndexTo++;
}
int aNumber = Integer.parseInt(new String(aChars, aIndex, aIndexTo - aIndex));
int bNumber = Integer.parseInt(new String(bChars, bIndex, bIndexTo - bIndex));
if (aNumber < bNumber) {
return -1;
} else if (aNumber > bNumber) {
return 1;
}
aIndex = aIndexTo;
bIndex = bIndexTo;
} else {
if (aChar < bChar) {
return -1;
} else if (aChar > bChar) {
return 1;
}
aIndex++;
bIndex++;
}
}
}
private boolean isDigit(char aChar) {
return aChar >= '0' && aChar <= '9';
}
}