Package org.apache.commons.io.comparator

Class SizeFileComparator

  • All Implemented Interfaces:
    java.io.Serializable, java.util.Comparator<java.io.File>
    public class SizeFileComparator
extends java.lang.Object
implements java.io.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 = ...
       ((AbstractFileComparator) SizeFileComparator.SIZE_COMPARATOR).sort(list);

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

           File[] array = ...
       ((AbstractFileComparator) SizeFileComparator.SIZE_REVERSE).sort(array);

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

    Since:
    1.4
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.util.Comparator<java.io.File> SIZE_COMPARATOR
      Size comparator instance - directories are treated as zero size
      static java.util.Comparator<java.io.File> SIZE_REVERSE
      Reverse size comparator instance - directories are treated as zero size
      static java.util.Comparator<java.io.File> SIZE_SUMDIR_COMPARATOR
      Size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)
      static java.util.Comparator<java.io.File> SIZE_SUMDIR_REVERSE
      Reverse size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)

    • Constructor Summary

      Constructors 
      Constructor Description
      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

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int compare​(java.io.File file1, java.io.File file2)
      Compare the length of two files.
      java.io.File[] sort​(java.io.File... files)
      Sort an array of files.
      java.util.List<java.io.File> sort​(java.util.List<java.io.File> files)
      Sort a List of files.
      java.lang.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

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

    • Field Detail

      • SIZE_COMPARATOR

        public static final java.util.Comparator<java.io.File> SIZE_COMPARATOR
        Size comparator instance - directories are treated as zero size

      • SIZE_REVERSE

        public static final java.util.Comparator<java.io.File> SIZE_REVERSE
        Reverse size comparator instance - directories are treated as zero size

      • SIZE_SUMDIR_COMPARATOR

        public static final java.util.Comparator<java.io.File> SIZE_SUMDIR_COMPARATOR
        Size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)

      • SIZE_SUMDIR_REVERSE

        public static final java.util.Comparator<java.io.File> SIZE_SUMDIR_REVERSE
        Reverse size comparator instance which sums the size of a directory's contents using FileUtils.sizeOfDirectory(File)

    • Constructor Detail

      • SizeFileComparator

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

      • SizeFileComparator

        public SizeFileComparator​(boolean sumDirectoryContents)
        Construct a file size comparator instance specifying whether the size of the directory contents should be aggregated.

        If the sumDirectoryContents is true The size of directories is calculated using FileUtils.sizeOfDirectory(File).

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

    • Method Detail

      • compare

        public int compare​(java.io.File file1,
                   java.io.File file2)
        Compare the length of two files.
        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:
        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.

      • toString

        public java.lang.String toString()
        String representation of this file comparator.
        Returns:
        String representation of this file comparator

      • sort

        public java.io.File[] sort​(java.io.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 java.util.List<java.io.File> sort​(java.util.List<java.io.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