org.apache.commons.io.comparator

Class NameFileComparator

java.lang.Object

org.apache.commons.io.comparator.NameFileComparator

All Implemented Interfaces:

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

public class NameFileComparator
extends java.lang.Object
implements java.io.Serializable

Compare the names of two files for order (see File.getName()).

This comparator can be used to sort lists or arrays of files by their name 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 name sort using the NAME_COMPARATOR singleton instance:

       List<File> list = ...
       ((AbstractFileComparator) NameFileComparator.NAME_COMPARATOR).sort(list);
 

Example of a reverse case-insensitive file name sort using the NAME_INSENSITIVE_REVERSE singleton instance:

       File[] array = ...
       ((AbstractFileComparator) NameFileComparator.NAME_INSENSITIVE_REVERSE).sort(array);
 

Since:

1.4

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Comparator<java.io.File>	NAME_COMPARATOR Case-sensitive name comparator instance (see IOCase.SENSITIVE)
static java.util.Comparator<java.io.File>	NAME_INSENSITIVE_COMPARATOR Case-insensitive name comparator instance (see IOCase.INSENSITIVE)
static java.util.Comparator<java.io.File>	NAME_INSENSITIVE_REVERSE Reverse case-insensitive name comparator instance (see IOCase.INSENSITIVE)
static java.util.Comparator<java.io.File>	NAME_REVERSE Reverse case-sensitive name comparator instance (see IOCase.SENSITIVE)
static java.util.Comparator<java.io.File>	NAME_SYSTEM_COMPARATOR System sensitive name comparator instance (see IOCase.SYSTEM)
static java.util.Comparator<java.io.File>	NAME_SYSTEM_REVERSE Reverse system sensitive name comparator instance (see IOCase.SYSTEM)

Constructor Summary

Constructors

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

Method Summary

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

Methods inherited from class java.lang.Object

equals, 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

NAME_COMPARATOR

public static final java.util.Comparator<java.io.File> NAME_COMPARATOR

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

NAME_REVERSE

public static final java.util.Comparator<java.io.File> NAME_REVERSE

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

NAME_INSENSITIVE_COMPARATOR

public static final java.util.Comparator<java.io.File> NAME_INSENSITIVE_COMPARATOR

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

NAME_INSENSITIVE_REVERSE

public static final java.util.Comparator<java.io.File> NAME_INSENSITIVE_REVERSE

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

NAME_SYSTEM_COMPARATOR

public static final java.util.Comparator<java.io.File> NAME_SYSTEM_COMPARATOR

System sensitive name comparator instance (see IOCase.SYSTEM)

NAME_SYSTEM_REVERSE

public static final java.util.Comparator<java.io.File> NAME_SYSTEM_REVERSE

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

Constructor Detail

NameFileComparator

public NameFileComparator()

Construct a case sensitive file name comparator instance.

NameFileComparator

public NameFileComparator(IOCase caseSensitivity)

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

Parameters:

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

Method Detail

compare

public int compare(java.io.File file1,
                   java.io.File file2)

Compare the names of two files with the specified case sensitivity.

Specified by:

compare in interface java.util.Comparator<java.io.File>

Parameters:

file1 - The first file to compare

file2 - The second file to compare

Returns:

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

toString

public java.lang.String toString()

String representation of this file comparator.

Returns:

String representation of this file comparator

sort

public java.io.File[] sort(java.io.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 java.util.List<java.io.File> sort(java.util.List<java.io.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