Package org.apache.commons.io.comparator

Class NameFileComparator

java.lang.Object

org.apache.commons.io.comparator.NameFileComparator

All Implemented Interfaces:

Serializable, Comparator<File>

public class NameFileComparator
extends Object
implements 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);
 

Deprecating Serialization

Serialization is deprecated and will be removed in 3.0.

Since:

1.4

See Also:

• Serialized Form

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor	Description
NameFileComparator()	Constructs a case-sensitive file name comparator instance.
NameFileComparator(IOCase ioCase)	Constructs a file name comparator instance with the specified case-sensitivity.

Method Summary

Modifier and Type	Method	Description
int	compare(File file1, File file2)	Compares the names of two files with the specified case sensitivity.
File[]	sort(File... files)	Sorts an array of files.
List<File>	sort(List<File> files)	Sorts 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

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

Field Details

NAME_COMPARATOR

public static final Comparator<File> NAME_COMPARATOR

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

NAME_REVERSE

public static final Comparator<File> NAME_REVERSE

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

NAME_INSENSITIVE_COMPARATOR

public static final Comparator<File> NAME_INSENSITIVE_COMPARATOR

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

NAME_INSENSITIVE_REVERSE

public static final Comparator<File> NAME_INSENSITIVE_REVERSE

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

NAME_SYSTEM_COMPARATOR

public static final Comparator<File> NAME_SYSTEM_COMPARATOR

System sensitive name comparator instance (see IOCase.SYSTEM)

NAME_SYSTEM_REVERSE

public static final Comparator<File> NAME_SYSTEM_REVERSE

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

Constructor Details

NameFileComparator

public NameFileComparator()

Constructs a case-sensitive file name comparator instance.

NameFileComparator

public NameFileComparator(IOCase ioCase)

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

Parameters:

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

Method Details

compare

public int compare(File file1,
 File file2)

Compares the names of two files with 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 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 String toString()

String representation of this file comparator.

Returns:

String representation of this file comparator

sort

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

Sorts 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)

Sorts a List of files.

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

Parameters:

files - The files to sort, may be null.

Returns:

The sorted list.

Since:

2.0