org.apache.commons.io.comparator

Class SizeFileComparator

Implemented Interfaces:
Comparator, Serializable

public class SizeFileComparator
extends java.lang.Object
implements Comparator, Serializable

Compare the length/size of two files for order (see File.length() and FileUtils.sizeOfDirectory(File)).

This comparator can be used to sort lists or arrays of files by their length/size.

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

       List<File> list = ...
       Collections.sort(list, LengthFileComparator.LENGTH_COMPARATOR);
 

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

       File[] array = ...
       Arrays.sort(array, LengthFileComparator.LENGTH_REVERSE);
 

N.B. Directories are treated as zero size unless sumDirectoryContents is true.

Version:
$Revision: 609243 $ $Date: 2008-01-06 00:30:42 +0000 (Sun, 06 Jan 2008) $
Since:
Commons IO 1.4

Field Summary

static Comparator
SIZE_COMPARATOR
Size comparator instance - directories are treated as zero size
static Comparator
SIZE_REVERSE
Reverse size comparator instance - directories are treated as zero size
static Comparator
SIZE_SUMDIR_COMPARATOR
Size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)
static Comparator
SIZE_SUMDIR_REVERSE
Reverse size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)
private boolean
sumDirectoryContents
Whether the sum of the directory's contents should be calculated.

Constructor Summary

SizeFileComparator()
Construct a file size comparator instance (directories treated as zero size).
SizeFileComparator(boolean sumDirectoryContents)
Construct a file size comparator instance specifying whether the size of the directory contents should be aggregated.

Method Summary

int
compare(Object obj1, Object obj2)
Compare the length of two files.

Field Details

SIZE_COMPARATOR

public static final Comparator SIZE_COMPARATOR
Size comparator instance - directories are treated as zero size

SIZE_REVERSE

public static final Comparator SIZE_REVERSE
Reverse size comparator instance - directories are treated as zero size

SIZE_SUMDIR_COMPARATOR

public static final Comparator SIZE_SUMDIR_COMPARATOR

SIZE_SUMDIR_REVERSE

public static final Comparator SIZE_SUMDIR_REVERSE

sumDirectoryContents

private final boolean sumDirectoryContents
Whether the sum of the directory's contents should be calculated.

Constructor Details

SizeFileComparator

public SizeFileComparator()
Construct a file size comparator instance (directories treated as zero size).

SizeFileComparator

public SizeFileComparator(boolean sumDirectoryContents)
Parameters:
sumDirectoryContents - true if the sum of the directoryies contents should be calculated, otherwise false if directories should be treated as size zero (see FileUtils.sizeOfDirectory(File)).

Method Details

compare

public int compare(Object obj1,
                   Object obj2)
Compare the length of two files.
Parameters:
obj1 - The first file to compare
obj2 - The second file to compare
Returns:
a negative value if the first file's length is less than the second, zero if the lengths are the same and a positive value if the first files length is greater than the second file.

Copyright (c) 2002-2008 Apache Software Foundation