Package org.apache.commons.io.comparator

Class DirectoryFileComparator

java.lang.Object

org.apache.commons.io.comparator.DirectoryFileComparator

All Implemented Interfaces:

Serializable, Comparator<File>

public class DirectoryFileComparator
extends Object
implements Serializable

Compare two files using the File.isDirectory() method.

This comparator can be used to sort lists or arrays by directories and files.

Example of sorting a list of files/directories using the DIRECTORY_COMPARATOR singleton instance:

       List<File> list = ...
       ((AbstractFileComparator) DirectoryFileComparator.DIRECTORY_COMPARATOR).sort(list);
 

Example of doing a reverse sort of an array of files/directories using the DIRECTORY_REVERSE singleton instance:

       File[] array = ...
       ((AbstractFileComparator) DirectoryFileComparator.DIRECTORY_REVERSE).sort(array);
 

Deprecating Serialization

Serialization is deprecated and will be removed in 3.0.

Since:

2.0

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final Comparator<File>	DIRECTORY_COMPARATOR	Singleton default comparator instance
static final Comparator<File>	DIRECTORY_REVERSE	Singleton reverse default comparator instance

Constructor Summary

Constructors

Constructor	Description
DirectoryFileComparator()

Method Summary

Modifier and Type	Method	Description
int	compare(File file1, File file2)	Compares the two files using the File.isDirectory() method.
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

DIRECTORY_COMPARATOR

public static final Comparator<File> DIRECTORY_COMPARATOR

Singleton default comparator instance

DIRECTORY_REVERSE

public static final Comparator<File> DIRECTORY_REVERSE

Singleton reverse default comparator instance

Constructor Details

DirectoryFileComparator

public DirectoryFileComparator()

Method Details

compare

public int compare(File file1,
 File file2)

Compares the two files using the File.isDirectory() method.

Specified by:

compare in interface Comparator<File>

Parameters:

file1 - The first file to compare.

file2 - The second file to compare.

Returns:

the result of calling file1's File.compareTo(File) with file2 as the parameter.

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

toString

public String toString()

String representation of this file comparator.

Overrides:

toString in class Object

Returns:

String representation of this file comparator.