Package org.apache.commons.io.comparator

Class CompositeFileComparator

  • All Implemented Interfaces:
    java.io.Serializable, java.util.Comparator<java.io.File>
    public class CompositeFileComparator
extends java.lang.Object
implements java.io.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 Description
      CompositeFileComparator​(java.lang.Iterable<java.util.Comparator<java.io.File>> delegates)
      Create a composite comparator for the set of delegate comparators.
      CompositeFileComparator​(java.util.Comparator<java.io.File>... delegates)
      Create a composite comparator for the set of delegate comparators.

    • 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 two files using delegate comparators.
      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

    • Constructor Detail

      • CompositeFileComparator

        public CompositeFileComparator​(java.util.Comparator<java.io.File>... delegates)
        Create a composite comparator for the set of delegate comparators.
        Parameters:
        delegates - The delegate file comparators

      • CompositeFileComparator

        public CompositeFileComparator​(java.lang.Iterable<java.util.Comparator<java.io.File>> delegates)
        Create a composite comparator for the set of delegate comparators.
        Parameters:
        delegates - The delegate file comparators

    • Method Detail

      • compare

        public int compare​(java.io.File file1,
                   java.io.File file2)
        Compare the two files using delegate comparators.
        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 first non-zero result returned from the delegate comparators or zero.

      • 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