Package org.apache.commons.io.comparator

Class DirectoryFileComparator

java.lang.Object

org.apache.commons.io.comparator.AbstractFileComparator

org.apache.commons.io.comparator.DirectoryFileComparator

All Implemented Interfaces:

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

public class DirectoryFileComparator
extends AbstractFileComparator
implements java.io.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 = ...
       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 = ...
       DirectoryFileComparator.DIRECTORY_REVERSE.sort(array);
 

Since:

2.0

Version:

$Id: DirectoryFileComparator.java 1304052 2012-03-22 20:55:29Z ggregory $

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static java.util.Comparator<java.io.File>	DIRECTORY_COMPARATOR	Singleton default comparator instance
static java.util.Comparator<java.io.File>	DIRECTORY_REVERSE	Singleton reverse default comparator instance

Constructor Summary

Constructors

Constructor	Description
DirectoryFileComparator()

Method Summary

Modifier and Type	Method	Description
int	compare(java.io.File file1, java.io.File file2)	Compare the two files using the File.isDirectory() method.
private int	getType(java.io.File file)	Convert type to numeric value.

Methods inherited from class org.apache.commons.io.comparator.AbstractFileComparator

sort, sort, toString

Methods inherited from interface java.util.Comparator

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DIRECTORY_COMPARATOR

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

Singleton default comparator instance

DIRECTORY_REVERSE

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

Singleton reverse default comparator instance

Constructor Detail

DirectoryFileComparator

public DirectoryFileComparator()

Method Detail

compare

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

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

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:

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

getType

private int getType(java.io.File file)

Convert type to numeric value.

Parameters:

file - The file

Returns:

1 for directories and 2 for files