Module org.sejda.commons

Package org.sejda.commons.util

Class NumericalSortFilenameComparator

java.lang.Object

org.sejda.commons.util.NumericalSortFilenameComparator

All Implemented Interfaces:

Comparator<File>

public class NumericalSortFilenameComparator
extends Object
implements Comparator<File>

Comparator for filenames that performs a numerical sort if the file names start or end with digits. It allows to specify a fallback comparator to use in case the numerical sort fails. The goal is to behave as close as possible to file managers sorting results.

Field Summary

Fields

Modifier and Type	Field	Description
private static final Comparator<String>	BIG_INT_COMPARATOR
private static final Function<String,BigInteger>	DIGITS_EXTRACTOR
private final Comparator<File>	fallback
private static final Comparator<Matcher>	MATCHER_COMPARATOR
private static final Pattern	PATTERN
private static final Comparator<String>	STRING_COMPARATOR

Constructor Summary

Constructors

Constructor	Description
NumericalSortFilenameComparator()	Comparator performing numerical sort with fallback to file name case-insensitive compare in case numerical sort fails
NumericalSortFilenameComparator(Comparator<File> fallback)

Method Summary

Modifier and Type	Method	Description
private static String	basename(File file)
int	compare(File a, File b)

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

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Details

PATTERN

private static final Pattern PATTERN

DIGITS_EXTRACTOR

private static final Function<String,BigInteger> DIGITS_EXTRACTOR

BIG_INT_COMPARATOR

private static final Comparator<String> BIG_INT_COMPARATOR

STRING_COMPARATOR

private static final Comparator<String> STRING_COMPARATOR

MATCHER_COMPARATOR

private static final Comparator<Matcher> MATCHER_COMPARATOR

fallback

private final Comparator<File> fallback

Constructor Details

NumericalSortFilenameComparator

public NumericalSortFilenameComparator(Comparator<File> fallback)

Parameters:

fallback - the comparator to use when numerical sorting fails. Default is file name case-insensitive compare

NumericalSortFilenameComparator

public NumericalSortFilenameComparator()

Comparator performing numerical sort with fallback to file name case-insensitive compare in case numerical sort fails

Method Details

basename

private static String basename(File file)

compare

public int compare(File a,
 File b)

Specified by:

compare in interface Comparator<File>