org.apache.commons.io.comparator

Class PathFileComparator

java.lang.Object

org.apache.commons.io.comparator.PathFileComparator

All Implemented Interfaces:

Serializable, Comparator<File>

public class PathFileComparator
extends Object
implements Serializable

Compare the path of two files for order (see File.getPath()).

This comparator can be used to sort lists or arrays of files by their path either in a case-sensitive, case-insensitive or system dependent case sensitive way. A number of singleton instances are provided for the various case sensitivity options (using IOCase) and the reverse of those options.

Example of a case-sensitive file path sort using the PATH_COMPARATOR singleton instance:

       List<File> list = ...
       ((AbstractFileComparator) PathFileComparator.PATH_COMPARATOR).sort(list);
 

Example of a reverse case-insensitive file path sort using the PATH_INSENSITIVE_REVERSE singleton instance:

       File[] array = ...
       ((AbstractFileComparator) PathFileComparator.PATH_INSENSITIVE_REVERSE).sort(array);
 

Since:

1.4

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<File>	PATH_COMPARATOR Case-sensitive path comparator instance (see IOCase.SENSITIVE)
static Comparator<File>	PATH_INSENSITIVE_COMPARATOR Case-insensitive path comparator instance (see IOCase.INSENSITIVE)
static Comparator<File>	PATH_INSENSITIVE_REVERSE Reverse case-insensitive path comparator instance (see IOCase.INSENSITIVE)
static Comparator<File>	PATH_REVERSE Reverse case-sensitive path comparator instance (see IOCase.SENSITIVE)
static Comparator<File>	PATH_SYSTEM_COMPARATOR System sensitive path comparator instance (see IOCase.SYSTEM)
static Comparator<File>	PATH_SYSTEM_REVERSE Reverse system sensitive path comparator instance (see IOCase.SYSTEM)

Constructor Summary

Constructors

Constructor and Description
PathFileComparator() Construct a case sensitive file path comparator instance.
PathFileComparator(IOCase caseSensitivity) Construct a file path comparator instance with the specified case-sensitivity.

Method Summary

Modifier and Type	Method and Description
int	compare(File file1, File file2) Compare the paths of two files the specified case sensitivity.
File[]	sort(File... files) Sort an array of files.
List<File>	sort(List<File> files) Sort a List of files.
String	toString() String representation of this file comparator.

Methods inherited from class java.lang.Object

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

Field Detail

PATH_COMPARATOR

public static final Comparator<File> PATH_COMPARATOR

Case-sensitive path comparator instance (see IOCase.SENSITIVE)

PATH_REVERSE

public static final Comparator<File> PATH_REVERSE

Reverse case-sensitive path comparator instance (see IOCase.SENSITIVE)

PATH_INSENSITIVE_COMPARATOR

public static final Comparator<File> PATH_INSENSITIVE_COMPARATOR

Case-insensitive path comparator instance (see IOCase.INSENSITIVE)

PATH_INSENSITIVE_REVERSE

public static final Comparator<File> PATH_INSENSITIVE_REVERSE

Reverse case-insensitive path comparator instance (see IOCase.INSENSITIVE)

PATH_SYSTEM_COMPARATOR

public static final Comparator<File> PATH_SYSTEM_COMPARATOR

System sensitive path comparator instance (see IOCase.SYSTEM)

PATH_SYSTEM_REVERSE

public static final Comparator<File> PATH_SYSTEM_REVERSE

Reverse system sensitive path comparator instance (see IOCase.SYSTEM)

Constructor Detail

PathFileComparator

public PathFileComparator()

Construct a case sensitive file path comparator instance.

PathFileComparator

public PathFileComparator(IOCase caseSensitivity)

Construct a file path comparator instance with the specified case-sensitivity.

Parameters:

caseSensitivity - how to handle case sensitivity, null means case-sensitive

Method Detail

compare

public int compare(File file1,
                   File file2)

Compare the paths of two files the specified case sensitivity.

Specified by:

compare in interface Comparator<File>

Parameters:

file1 - The first file to compare

file2 - The second file to compare

Returns:

a negative value if the first file's path is less than the second, zero if the paths are the same and a positive value if the first files path is greater than the second file.

toString

public String toString()

String representation of this file comparator.

Returns:

String representation of this file comparator

sort

public File[] sort(File... files)

Sort an array of files.

This method uses Arrays.sort(Object[], Comparator) and returns the original array.

Parameters:

files - The files to sort, may be null

Returns:

The sorted array

Since:

2.0

sort

public List<File> sort(List<File> files)

Sort a List of files.

This method uses Collections.sort(List, Comparator) and returns the original list.

Parameters:

files - The files to sort, may be null

Returns:

The sorted list

Since:

2.0