org.apache.commons.io.comparator

类 ExtensionFileComparator

java.lang.Object

org.apache.commons.io.comparator.ExtensionFileComparator

所有已实现的接口:

Serializable, Comparator<File>

public class ExtensionFileComparator
extends Object
implements Serializable

Compare the file name extensions for order (see FilenameUtils.getExtension(String)).

This comparator can be used to sort lists or arrays of files by their file extension either in a case-sensitive, case-insensitive or system dependent 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 extension sort using the EXTENSION_COMPARATOR singleton instance:

       List<File> list = ...
       ((AbstractFileComparator) ExtensionFileComparator.EXTENSION_COMPARATOR).sort(list);
 

Example of a reverse case-insensitive file extension sort using the EXTENSION_INSENSITIVE_REVERSE singleton instance:

       File[] array = ...
       ((AbstractFileComparator) ExtensionFileComparator.EXTENSION_INSENSITIVE_REVERSE).sort(array);
 

从以下版本开始:

1.4

另请参阅:

序列化表格

字段概要

字段

限定符和类型	字段和说明
static Comparator<File>	EXTENSION_COMPARATOR Case-sensitive extension comparator instance (see IOCase.SENSITIVE)
static Comparator<File>	EXTENSION_INSENSITIVE_COMPARATOR Case-insensitive extension comparator instance (see IOCase.INSENSITIVE)
static Comparator<File>	EXTENSION_INSENSITIVE_REVERSE Reverse case-insensitive extension comparator instance (see IOCase.INSENSITIVE)
static Comparator<File>	EXTENSION_REVERSE Reverse case-sensitive extension comparator instance (see IOCase.SENSITIVE)
static Comparator<File>	EXTENSION_SYSTEM_COMPARATOR System sensitive extension comparator instance (see IOCase.SYSTEM)
static Comparator<File>	EXTENSION_SYSTEM_REVERSE Reverse system sensitive path comparator instance (see IOCase.SYSTEM)

构造器概要

构造器

构造器和说明
ExtensionFileComparator() Construct a case sensitive file extension comparator instance.
ExtensionFileComparator(IOCase caseSensitivity) Construct a file extension comparator instance with the specified case-sensitivity.

方法概要

限定符和类型	方法和说明
int	compare(File file1, File file2) Compare the extensions of two files 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.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口继承的方法 java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

字段详细资料

EXTENSION_COMPARATOR

public static final Comparator<File> EXTENSION_COMPARATOR

Case-sensitive extension comparator instance (see IOCase.SENSITIVE)

EXTENSION_REVERSE

public static final Comparator<File> EXTENSION_REVERSE

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

EXTENSION_INSENSITIVE_COMPARATOR

public static final Comparator<File> EXTENSION_INSENSITIVE_COMPARATOR

Case-insensitive extension comparator instance (see IOCase.INSENSITIVE)

EXTENSION_INSENSITIVE_REVERSE

public static final Comparator<File> EXTENSION_INSENSITIVE_REVERSE

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

EXTENSION_SYSTEM_COMPARATOR

public static final Comparator<File> EXTENSION_SYSTEM_COMPARATOR

System sensitive extension comparator instance (see IOCase.SYSTEM)

EXTENSION_SYSTEM_REVERSE

public static final Comparator<File> EXTENSION_SYSTEM_REVERSE

Reverse system sensitive path comparator instance (see IOCase.SYSTEM)

构造器详细资料

ExtensionFileComparator

public ExtensionFileComparator()

Construct a case sensitive file extension comparator instance.

ExtensionFileComparator

public ExtensionFileComparator(IOCase caseSensitivity)

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

参数:

caseSensitivity - how to handle case sensitivity, null means case-sensitive

方法详细资料

compare

public int compare(File file1,
                   File file2)

Compare the extensions of two files the specified case sensitivity.

指定者:

compare 在接口中 Comparator<File>

参数:

file1 - The first file to compare

file2 - The second file to compare

返回:

a negative value if the first file's extension is less than the second, zero if the extensions are the same and a positive value if the first files extension is greater than the second file.

toString

public String toString()

String representation of this file comparator.

返回:

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.

参数:

files - The files to sort, may be null

返回:

The sorted array

从以下版本开始:

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.

参数:

files - The files to sort, may be null

返回:

The sorted list

从以下版本开始:

2.0