org.apache.commons.io.comparator

Class CompositeFileComparator

java.lang.Object

org.apache.commons.io.comparator.CompositeFileComparator

All Implemented Interfaces:

Serializable, Comparator<File>

public class CompositeFileComparator
extends Object
implements Serializable

Compare two files using a set of delegate file Comparator.

This comparator can be used to sort lists or arrays of files by combining a number other comparators.

Example of sorting a list of files by type (i.e. directory or file) and then by name:

       CompositeFileComparator comparator =
                       new CompositeFileComparator(
                                 (AbstractFileComparator) DirectoryFileComparator.DIRECTORY_COMPARATOR,
                                 (AbstractFileComparator) NameFileComparator.NAME_COMPARATOR);
       List<File> list = ...
       comparator.sort(list);
 

Since:

2.0

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CompositeFileComparator(Comparator<File>... delegates) Create a composite comparator for the set of delegate comparators.
CompositeFileComparator(Iterable<Comparator<File>> delegates) Create a composite comparator for the set of delegate comparators.

Method Summary

Modifier and Type	Method and Description
int	compare(File file1, File file2) Compare the two files using delegate comparators.
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

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

Constructor Detail

CompositeFileComparator

public CompositeFileComparator(Comparator<File>... delegates)

Create a composite comparator for the set of delegate comparators.

Parameters:

delegates - The delegate file comparators

CompositeFileComparator

public CompositeFileComparator(Iterable<Comparator<File>> delegates)

Create a composite comparator for the set of delegate comparators.

Parameters:

delegates - The delegate file comparators

Method Detail

compare

public int compare(File file1,
                   File file2)

Compare the two files using delegate comparators.

Specified by:

compare in interface Comparator<File>

Parameters:

file1 - The first file to compare

file2 - The second file to compare

Returns:

the first non-zero result returned from the delegate comparators or zero.

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