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 = ...
       ((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 and 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
private static long	serialVersionUID
private static int	TYPE_DIRECTORY
private static int	TYPE_FILE

Constructor Summary

Constructors

Constructor and Description
DirectoryFileComparator()

Method Summary

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

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

sort, sort, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, 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

Field Detail

TYPE_FILE

private static final int TYPE_FILE

See Also:

Constant Field Values

TYPE_DIRECTORY

private static final int TYPE_DIRECTORY

See Also:

Constant Field Values

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

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)

Compares 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)

Converts type to numeric value.

Parameters:

file - The file.

Returns:

1 for directories and 2 for files.