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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 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';
}
}