Package org.apache.commons.io.comparator

Class LastModifiedFileComparator

java.lang.Object

org.apache.commons.io.comparator.LastModifiedFileComparator

All Implemented Interfaces:

Serializable, Comparator<File>

public class LastModifiedFileComparator
extends Object
implements Serializable

Compare the last modified date/time of two files for order (see FileUtils.lastModifiedUnchecked(File)).

This comparator can be used to sort lists or arrays of files by their last modified date/time.

Example of sorting a list of files using the LASTMODIFIED_COMPARATOR singleton instance:

       List<File> list = ...
       ((AbstractFileComparator) LastModifiedFileComparator.LASTMODIFIED_COMPARATOR).sort(list);
 

Example of doing a reverse sort of an array of files using the LASTMODIFIED_REVERSE singleton instance:

       File[] array = ...
       ((AbstractFileComparator) LastModifiedFileComparator.LASTMODIFIED_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>	LASTMODIFIED_COMPARATOR	Last modified comparator instance.
static final Comparator<File>	LASTMODIFIED_REVERSE	Reverse last modified comparator instance.

Constructor Summary

Constructors

Constructor	Description
LastModifiedFileComparator()

Method Summary

Modifier and Type	Method	Description
int	compare(File file1, File file2)	Compares the last modified date/time of two files.
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

LASTMODIFIED_COMPARATOR

public static final Comparator<File> LASTMODIFIED_COMPARATOR

Last modified comparator instance.

LASTMODIFIED_REVERSE

public static final Comparator<File> LASTMODIFIED_REVERSE

Reverse last modified comparator instance.

Constructor Details

LastModifiedFileComparator

public LastModifiedFileComparator()

Method Details

compare

public int compare(File file1,
 File file2)

Compares the last modified date/time of two files.

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 last modified date/time is less than the second, zero if the last modified date/time are the same and a positive value if the first files last modified date/time is greater than the second file.

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.