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## org.apache.commons.io.comparator
Class NameFileComparator

    java.lang.Object
      org.apache.commons.io.comparator.NameFileComparator

All Implemented Interfaces:
  Serializable, Comparator<File>

    public class NameFileComparator

extends Object
implements Serializable

Compare the names of two files for order (see `File.getName()`).

This comparator can be used to sort lists or arrays of files by their name either in a case-sensitive, case-insensitive or system dependant case sensitive way. A number of singleton instances are provided for the various case sensitivity options (using `IOCase`) and the reverse of those options.

Example of a case-sensitive file name sort using the `NAME_COMPARATOR` singleton instance:

           List<File> list = ...
           NameFileComparator.NAME_COMPARATOR.sort(list);

Example of a reverse case-insensitive file name sort using the `NAME_INSENSITIVE_REVERSE` singleton instance:

           File[] array = ...
           NameFileComparator.NAME_INSENSITIVE_REVERSE.sort(array);

Since:
  1.4
Version:
  $Id: NameFileComparator.java 1304052 2012-03-22 20:55:29Z ggregory $
See Also:
  Serialized Form

Field Summary
`static Comparator<File>` | `NAME_COMPARATOR` Case-sensitive name comparator instance (see `IOCase.SENSITIVE`)
`static Comparator<File>` | `NAME_INSENSITIVE_COMPARATOR` Case-insensitive name comparator instance (see `IOCase.INSENSITIVE`)
`static Comparator<File>` | `NAME_INSENSITIVE_REVERSE` Reverse case-insensitive name comparator instance (see `IOCase.INSENSITIVE`)
`static Comparator<File>` | `NAME_REVERSE` Reverse case-sensitive name comparator instance (see `IOCase.SENSITIVE`)
`static Comparator<File>` | `NAME_SYSTEM_COMPARATOR` System sensitive name comparator instance (see `IOCase.SYSTEM`)
`static Comparator<File>` | `NAME_SYSTEM_REVERSE` Reverse system sensitive name comparator instance (see `IOCase.SYSTEM`)

Constructor Summary
`NameFileComparator()` Construct a case sensitive file name comparator instance.
`NameFileComparator(IOCase caseSensitivity)` Construct a file name comparator instance with the specified case-sensitivity.

Method Summary
`int` | `compare(File file1, File file2)` Compare the names of two files with the specified case sensitivity.
`File[]` | `sort(File... files)` Sort an array of files.
`List<File>` | `sort(List<File> files)` Sort a List of files.
`String` | `toString()` String representation of this file comparator.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Methods inherited from interface java.util.Comparator
`equals`

Field Detail

### NAME_COMPARATOR

    public static final Comparator<File> NAME_COMPARATOR

  Case-sensitive name comparator instance (see `IOCase.SENSITIVE`)

### NAME_REVERSE

    public static final Comparator<File> NAME_REVERSE

  Reverse case-sensitive name comparator instance (see `IOCase.SENSITIVE`)

### NAME_INSENSITIVE_COMPARATOR

    public static final Comparator<File> NAME_INSENSITIVE_COMPARATOR

  Case-insensitive name comparator instance (see `IOCase.INSENSITIVE`)

### NAME_INSENSITIVE_REVERSE

    public static final Comparator<File> NAME_INSENSITIVE_REVERSE

  Reverse case-insensitive name comparator instance (see `IOCase.INSENSITIVE`)

### NAME_SYSTEM_COMPARATOR

    public static final Comparator<File> NAME_SYSTEM_COMPARATOR

  System sensitive name comparator instance (see `IOCase.SYSTEM`)

### NAME_SYSTEM_REVERSE

    public static final Comparator<File> NAME_SYSTEM_REVERSE

  Reverse system sensitive name comparator instance (see `IOCase.SYSTEM`)

Constructor Detail

### NameFileComparator

    public NameFileComparator()

  Construct a case sensitive file name comparator instance.

### NameFileComparator

    public NameFileComparator(IOCase caseSensitivity)

  Construct a file name comparator instance with the specified case-sensitivity.

  Parameters:
    `caseSensitivity` - how to handle case sensitivity, null means case-sensitive

Method Detail

### compare

    public int compare(File file1,
                       File file2)

  Compare the names of two files with the specified case sensitivity.

  Specified by:
    `compare` in interface `Comparator<File>`
  Parameters:
    `file1` - The first file to compare
    `file2` - The second file to compare
  Returns:
    a negative value if the first file's name is less than the second, zero if the names are the same and a positive value if the first files name is greater than the second file.

### toString

    public String toString()

  String representation of this file comparator.

  Returns:
    String representation of this file comparator

### sort

    public File[] sort(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 List<File> sort(List<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

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