org.restlet.engine.util

Class AlphaNumericComparator

java.lang.Object

org.restlet.engine.util.AlphabeticalComparator

org.restlet.engine.util.AlphaNumericComparator

All Implemented Interfaces:

java.io.Serializable, java.util.Comparator<Reference>

public class AlphaNumericComparator
extends AlphabeticalComparator

Optimized public-domain implementation of a Java alphanumeric sort.

This implementation uses a single comparison pass over the characters in a CharSequence, and returns as soon as a differing character is found, unless the difference occurs in a series of numeric characters, in which case that series is followed to its end. Numeric series of equal length are compared numerically, that is, according to the most significant (leftmost) differing digit. Series of unequal length are compared by their length.

This implementation appears to be 2-5 times faster than alphanumeric comparators based based on substring analysis, with a lighter memory footprint.

This alphanumeric comparator has approximately 20%-50% the performance of the lexical String.compareTo() operation. Character sequences without numeric data are compared more quickly.

Dedicated to the public domain by the original author: http://creativecommons.org/licenses/publicdomain/

Author:

Rob Heittman, Solertium Corporation

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AlphaNumericComparator()

Method Summary

Modifier and Type	Method and Description
int	compare(java.lang.String uri0, java.lang.String uri1) Compares two strings.
protected boolean	isNotDigit(char x) Indicates if the character is a digit.

Methods inherited from class org.restlet.engine.util.AlphabeticalComparator

compare

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

AlphaNumericComparator

public AlphaNumericComparator()

Method Detail

compare

public int compare(java.lang.String uri0,
                   java.lang.String uri1)

Description copied from class: AlphabeticalComparator

Compares two strings.

Overrides:

compare in class AlphabeticalComparator

Parameters:

uri0 - The first string.

uri1 - The second string.

Returns:

The comparison result.

See Also:

Comparator

isNotDigit

protected boolean isNotDigit(char x)

Indicates if the character is a digit.

Parameters:

x - The character to test.

Returns:

True if the character is a digit.