org.apache.commons.io.filefilter

Class FileFilterUtils

java.lang.Object

org.apache.commons.io.filefilter.FileFilterUtils

public class FileFilterUtils
extends Object

Useful utilities for working with file filters. It provides access to most file filter implementations in this package so you don't have to import every class you use.

Since:

1.0

Constructor Summary

Constructors

Constructor and Description
FileFilterUtils() FileFilterUtils is not normally instantiated.

Method Summary

Modifier and Type	Method and Description
static IOFileFilter	ageFileFilter(Date cutoffDate) Returns a filter that returns true if the file was last modified before or at the specified cutoff date.
static IOFileFilter	ageFileFilter(Date cutoffDate, boolean acceptOlder) Returns a filter that filters files based on a cutoff date.
static IOFileFilter	ageFileFilter(File cutoffReference) Returns a filter that returns true if the file was last modified before or at the same time as the specified reference file.
static IOFileFilter	ageFileFilter(File cutoffReference, boolean acceptOlder) Returns a filter that filters files based on a cutoff reference file.
static IOFileFilter	ageFileFilter(long cutoffMillis) Returns a filter that returns true if the file was last modified before or at the specified cutoff time.
static IOFileFilter	ageFileFilter(long cutoffMillis, boolean acceptOlder) Returns a filter that filters files based on a cutoff time.
static IOFileFilter	and(IOFileFilter... filters) Returns a filter that ANDs the specified filters.
static IOFileFilter	andFileFilter(IOFileFilter filter1, IOFileFilter filter2) Deprecated. use and(IOFileFilter...)
static IOFileFilter	asFileFilter(FileFilter filter) Returns an IOFileFilter that wraps the FileFilter instance.
static IOFileFilter	asFileFilter(FilenameFilter filter) Returns an IOFileFilter that wraps the FilenameFilter instance.
static IOFileFilter	directoryFileFilter() Returns a filter that checks if the file is a directory.
static IOFileFilter	falseFileFilter() Returns a filter that always returns false.
static IOFileFilter	fileFileFilter() Returns a filter that checks if the file is a file (and not a directory).
static File[]	filter(IOFileFilter filter, File... files) Applies an IOFileFilter to the provided File objects.
static File[]	filter(IOFileFilter filter, Iterable<File> files) Applies an IOFileFilter to the provided File objects.
static List<File>	filterList(IOFileFilter filter, File... files) Applies an IOFileFilter to the provided File objects.
static List<File>	filterList(IOFileFilter filter, Iterable<File> files) Applies an IOFileFilter to the provided File objects.
static Set<File>	filterSet(IOFileFilter filter, File... files) Applies an IOFileFilter to the provided File objects.
static Set<File>	filterSet(IOFileFilter filter, Iterable<File> files) Applies an IOFileFilter to the provided File objects.
static IOFileFilter	magicNumberFileFilter(byte[] magicNumber) Returns a filter that accepts files that begin with the provided magic number.
static IOFileFilter	magicNumberFileFilter(byte[] magicNumber, long offset) Returns a filter that accepts files that contains the provided magic number at a specified offset within the file.
static IOFileFilter	magicNumberFileFilter(String magicNumber) Returns a filter that accepts files that begin with the provided magic number.
static IOFileFilter	magicNumberFileFilter(String magicNumber, long offset) Returns a filter that accepts files that contains the provided magic number at a specified offset within the file.
static IOFileFilter	makeCVSAware(IOFileFilter filter) Decorates a filter to make it ignore CVS directories.
static IOFileFilter	makeDirectoryOnly(IOFileFilter filter) Decorates a filter so that it only applies to directories and not to files.
static IOFileFilter	makeFileOnly(IOFileFilter filter) Decorates a filter so that it only applies to files and not to directories.
static IOFileFilter	makeSVNAware(IOFileFilter filter) Decorates a filter to make it ignore SVN directories.
static IOFileFilter	nameFileFilter(String name) Returns a filter that returns true if the file name matches the specified text.
static IOFileFilter	nameFileFilter(String name, IOCase ioCase) Returns a filter that returns true if the file name matches the specified text.
static IOFileFilter	notFileFilter(IOFileFilter filter) Returns a filter that NOTs the specified filter.
static IOFileFilter	or(IOFileFilter... filters) Returns a filter that ORs the specified filters.
static IOFileFilter	orFileFilter(IOFileFilter filter1, IOFileFilter filter2) Deprecated. use or(IOFileFilter...)
static IOFileFilter	prefixFileFilter(String prefix) Returns a filter that returns true if the file name starts with the specified text.
static IOFileFilter	prefixFileFilter(String prefix, IOCase ioCase) Returns a filter that returns true if the file name starts with the specified text.
static IOFileFilter	sizeFileFilter(long threshold) Returns a filter that returns true if the file is bigger than a certain size.
static IOFileFilter	sizeFileFilter(long threshold, boolean acceptLarger) Returns a filter that filters based on file size.
static IOFileFilter	sizeRangeFileFilter(long minSizeInclusive, long maxSizeInclusive) Returns a filter that accepts files whose size is >= minimum size and <= maximum size.
static IOFileFilter	suffixFileFilter(String suffix) Returns a filter that returns true if the file name ends with the specified text.
static IOFileFilter	suffixFileFilter(String suffix, IOCase ioCase) Returns a filter that returns true if the file name ends with the specified text.
static List<IOFileFilter>	toList(IOFileFilter... filters) Create a List of file filters.
static IOFileFilter	trueFileFilter() Returns a filter that always returns true.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileFilterUtils

public FileFilterUtils()

FileFilterUtils is not normally instantiated.

Method Detail

ageFileFilter

public static IOFileFilter ageFileFilter(Date cutoffDate)

Returns a filter that returns true if the file was last modified before or at the specified cutoff date.

Parameters:

cutoffDate - the time threshold

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

ageFileFilter

public static IOFileFilter ageFileFilter(Date cutoffDate,
                                         boolean acceptOlder)

Returns a filter that filters files based on a cutoff date.

Parameters:

cutoffDate - the time threshold

acceptOlder - if true, older files get accepted, if false, newer

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

ageFileFilter

public static IOFileFilter ageFileFilter(File cutoffReference)

Returns a filter that returns true if the file was last modified before or at the same time as the specified reference file.

Parameters:

cutoffReference - the file whose last modification time is used as the threshold age of the files

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

ageFileFilter

public static IOFileFilter ageFileFilter(File cutoffReference,
                                         boolean acceptOlder)

Returns a filter that filters files based on a cutoff reference file.

Parameters:

cutoffReference - the file whose last modification time is used as the threshold age of the files

acceptOlder - if true, older files get accepted, if false, newer

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

ageFileFilter

public static IOFileFilter ageFileFilter(long cutoffMillis)

Returns a filter that returns true if the file was last modified before or at the specified cutoff time.

Parameters:

cutoffMillis - the time threshold

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

ageFileFilter

public static IOFileFilter ageFileFilter(long cutoffMillis,
                                         boolean acceptOlder)

Returns a filter that filters files based on a cutoff time.

Parameters:

cutoffMillis - the time threshold

acceptOlder - if true, older files get accepted, if false, newer

Returns:

an appropriately configured age file filter

Since:

1.2

See Also:

AgeFileFilter

and

public static IOFileFilter and(IOFileFilter... filters)

Returns a filter that ANDs the specified filters.

Parameters:

filters - the IOFileFilters that will be ANDed together.

Returns:

a filter that ANDs the specified filters

Throws:

IllegalArgumentException - if the filters are null or contain a null value.

Since:

2.0

See Also:

AndFileFilter

andFileFilter

@Deprecated
public static IOFileFilter andFileFilter(IOFileFilter filter1,
                                                     IOFileFilter filter2)

Deprecated. use and(IOFileFilter...)

Returns a filter that ANDs the two specified filters.

Parameters:

filter1 - the first filter

filter2 - the second filter

Returns:

a filter that ANDs the two specified filters

See Also:

and(IOFileFilter...), AndFileFilter

asFileFilter

public static IOFileFilter asFileFilter(FileFilter filter)

Returns an IOFileFilter that wraps the FileFilter instance.

Parameters:

filter - the filter to be wrapped

Returns:

a new filter that implements IOFileFilter

See Also:

DelegateFileFilter

asFileFilter

public static IOFileFilter asFileFilter(FilenameFilter filter)

Returns an IOFileFilter that wraps the FilenameFilter instance.

Parameters:

filter - the filter to be wrapped

Returns:

a new filter that implements IOFileFilter

See Also:

DelegateFileFilter

directoryFileFilter

public static IOFileFilter directoryFileFilter()

Returns a filter that checks if the file is a directory.

Returns:

file filter that accepts only directories and not files

See Also:

DirectoryFileFilter.DIRECTORY

falseFileFilter

public static IOFileFilter falseFileFilter()

Returns a filter that always returns false.

Returns:

a false filter

See Also:

FalseFileFilter.FALSE

fileFileFilter

public static IOFileFilter fileFileFilter()

Returns a filter that checks if the file is a file (and not a directory).

Returns:

file filter that accepts only files and not directories

See Also:

FileFileFilter.INSTANCE

filter

public static File[] filter(IOFileFilter filter,
                            File... files)

Applies an IOFileFilter to the provided File objects. The resulting array is a subset of the original file list that matches the provided filter.

 Set<File> allFiles = ...
 Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
     FileFilterUtils.suffixFileFilter(".java"));
 

Parameters:

filter - the filter to apply to the set of files.

files - the array of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

NullPointerException - if the filter is null or files contains a null value.

Since:

2.0

filter

public static File[] filter(IOFileFilter filter,
                            Iterable<File> files)

Applies an IOFileFilter to the provided File objects. The resulting array is a subset of the original file list that matches the provided filter.

The Set returned by this method is not guaranteed to be thread safe.

 Set<File> allFiles = ...
 Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
     FileFilterUtils.suffixFileFilter(".java"));
 

Parameters:

filter - the filter to apply to the set of files.

files - the array of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

IllegalArgumentException - if the filter is null or files contains a null value.

Since:

2.0

filterList

public static List<File> filterList(IOFileFilter filter,
                                    File... files)

Applies an IOFileFilter to the provided File objects. The resulting list is a subset of the original files that matches the provided filter.

The List returned by this method is not guaranteed to be thread safe.

 List<File> filesAndDirectories = ...
 List<File> directories = FileFilterUtils.filterList(filesAndDirectories,
     FileFilterUtils.directoryFileFilter());
 

Parameters:

filter - the filter to apply to each files in the list.

files - the collection of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

IllegalArgumentException - if the filter is null or files contains a null value.

Since:

2.0

filterList

public static List<File> filterList(IOFileFilter filter,
                                    Iterable<File> files)

Applies an IOFileFilter to the provided File objects. The resulting list is a subset of the original files that matches the provided filter.

The List returned by this method is not guaranteed to be thread safe.

 List<File> filesAndDirectories = ...
 List<File> directories = FileFilterUtils.filterList(filesAndDirectories,
     FileFilterUtils.directoryFileFilter());
 

Parameters:

filter - the filter to apply to each files in the list.

files - the collection of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

IllegalArgumentException - if the filter is null

Since:

2.0

filterSet

public static Set<File> filterSet(IOFileFilter filter,
                                  File... files)

Applies an IOFileFilter to the provided File objects. The resulting set is a subset of the original file list that matches the provided filter.

The Set returned by this method is not guaranteed to be thread safe.

 Set<File> allFiles = ...
 Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
     FileFilterUtils.suffixFileFilter(".java"));
 

Parameters:

filter - the filter to apply to the set of files.

files - the collection of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

IllegalArgumentException - if the filter is null or files contains a null value.

Since:

2.0

filterSet

public static Set<File> filterSet(IOFileFilter filter,
                                  Iterable<File> files)

Applies an IOFileFilter to the provided File objects. The resulting set is a subset of the original file list that matches the provided filter.

The Set returned by this method is not guaranteed to be thread safe.

 Set<File> allFiles = ...
 Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
     FileFilterUtils.suffixFileFilter(".java"));
 

Parameters:

filter - the filter to apply to the set of files.

files - the collection of files to apply the filter to.

Returns:

a subset of files that is accepted by the file filter.

Throws:

IllegalArgumentException - if the filter is null

Since:

2.0

magicNumberFileFilter

public static IOFileFilter magicNumberFileFilter(byte[] magicNumber)

Returns a filter that accepts files that begin with the provided magic number.

Parameters:

magicNumber - the magic number (byte sequence) to match at the beginning of each file.

Returns:

an IOFileFilter that accepts files beginning with the provided magic number.

Throws:

IllegalArgumentException - if magicNumber is null or is of length zero.

Since:

2.0

See Also:

MagicNumberFileFilter

magicNumberFileFilter

public static IOFileFilter magicNumberFileFilter(byte[] magicNumber,
                                                 long offset)

Returns a filter that accepts files that contains the provided magic number at a specified offset within the file.

Parameters:

magicNumber - the magic number (byte sequence) to match at the provided offset in each file.

offset - the offset within the files to look for the magic number.

Returns:

an IOFileFilter that accepts files containing the magic number at the specified offset.

Throws:

IllegalArgumentException - if magicNumber is null, or contains no bytes, or offset is a negative number.

Since:

2.0

See Also:

MagicNumberFileFilter

magicNumberFileFilter

public static IOFileFilter magicNumberFileFilter(String magicNumber)

Returns a filter that accepts files that begin with the provided magic number.

Parameters:

magicNumber - the magic number (byte sequence) to match at the beginning of each file.

Returns:

an IOFileFilter that accepts files beginning with the provided magic number.

Throws:

IllegalArgumentException - if magicNumber is null or the empty String.

Since:

2.0

See Also:

MagicNumberFileFilter

magicNumberFileFilter

public static IOFileFilter magicNumberFileFilter(String magicNumber,
                                                 long offset)

Returns a filter that accepts files that contains the provided magic number at a specified offset within the file.

Parameters:

magicNumber - the magic number (byte sequence) to match at the provided offset in each file.

offset - the offset within the files to look for the magic number.

Returns:

an IOFileFilter that accepts files containing the magic number at the specified offset.

Throws:

IllegalArgumentException - if magicNumber is null or the empty String, or if offset is a negative number.

Since:

2.0

See Also:

MagicNumberFileFilter

makeCVSAware

public static IOFileFilter makeCVSAware(IOFileFilter filter)

Decorates a filter to make it ignore CVS directories. Passing in null will return a filter that accepts everything except CVS directories.

Parameters:

filter - the filter to decorate, null means an unrestricted filter

Returns:

the decorated filter, never null

Since:

1.1 (method existed but had a bug in 1.0)

makeDirectoryOnly

public static IOFileFilter makeDirectoryOnly(IOFileFilter filter)

Decorates a filter so that it only applies to directories and not to files.

Parameters:

filter - the filter to decorate, null means an unrestricted filter

Returns:

the decorated filter, never null

Since:

1.3

See Also:

DirectoryFileFilter.DIRECTORY

makeFileOnly

public static IOFileFilter makeFileOnly(IOFileFilter filter)

Decorates a filter so that it only applies to files and not to directories.

Parameters:

filter - the filter to decorate, null means an unrestricted filter

Returns:

the decorated filter, never null

Since:

1.3

See Also:

FileFileFilter.INSTANCE

makeSVNAware

public static IOFileFilter makeSVNAware(IOFileFilter filter)

Decorates a filter to make it ignore SVN directories. Passing in null will return a filter that accepts everything except SVN directories.

Parameters:

filter - the filter to decorate, null means an unrestricted filter

Returns:

the decorated filter, never null

Since:

1.1

nameFileFilter

public static IOFileFilter nameFileFilter(String name)

Returns a filter that returns true if the file name matches the specified text.

Parameters:

name - the file name

Returns:

a name checking filter

See Also:

NameFileFilter

nameFileFilter

public static IOFileFilter nameFileFilter(String name,
                                          IOCase ioCase)

Returns a filter that returns true if the file name matches the specified text.

Parameters:

name - the file name

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

Returns:

a name checking filter

Since:

2.0

See Also:

NameFileFilter

notFileFilter

public static IOFileFilter notFileFilter(IOFileFilter filter)

Returns a filter that NOTs the specified filter.

Parameters:

filter - the filter to invert

Returns:

a filter that NOTs the specified filter

See Also:

NotFileFilter

or

public static IOFileFilter or(IOFileFilter... filters)

Returns a filter that ORs the specified filters.

Parameters:

filters - the IOFileFilters that will be ORed together.

Returns:

a filter that ORs the specified filters

Throws:

IllegalArgumentException - if the filters are null or contain a null value.

Since:

2.0

See Also:

OrFileFilter

orFileFilter

@Deprecated
public static IOFileFilter orFileFilter(IOFileFilter filter1,
                                                    IOFileFilter filter2)

Deprecated. use or(IOFileFilter...)

Returns a filter that ORs the two specified filters.

Parameters:

filter1 - the first filter

filter2 - the second filter

Returns:

a filter that ORs the two specified filters

See Also:

or(IOFileFilter...), OrFileFilter

prefixFileFilter

public static IOFileFilter prefixFileFilter(String prefix)

Returns a filter that returns true if the file name starts with the specified text.

Parameters:

prefix - the file name prefix

Returns:

a prefix checking filter

See Also:

PrefixFileFilter

prefixFileFilter

public static IOFileFilter prefixFileFilter(String prefix,
                                            IOCase ioCase)

Returns a filter that returns true if the file name starts with the specified text.

Parameters:

prefix - the file name prefix

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

Returns:

a prefix checking filter

Since:

2.0

See Also:

PrefixFileFilter

sizeFileFilter

public static IOFileFilter sizeFileFilter(long threshold)

Returns a filter that returns true if the file is bigger than a certain size.

Parameters:

threshold - the file size threshold

Returns:

an appropriately configured SizeFileFilter

Since:

1.2

See Also:

SizeFileFilter

sizeFileFilter

public static IOFileFilter sizeFileFilter(long threshold,
                                          boolean acceptLarger)

Returns a filter that filters based on file size.

Parameters:

threshold - the file size threshold

acceptLarger - if true, larger files get accepted, if false, smaller

Returns:

an appropriately configured SizeFileFilter

Since:

1.2

See Also:

SizeFileFilter

sizeRangeFileFilter

public static IOFileFilter sizeRangeFileFilter(long minSizeInclusive,
                                               long maxSizeInclusive)

Returns a filter that accepts files whose size is >= minimum size and <= maximum size.

Parameters:

minSizeInclusive - the minimum file size (inclusive)

maxSizeInclusive - the maximum file size (inclusive)

Returns:

an appropriately configured IOFileFilter

Since:

1.3

See Also:

SizeFileFilter

suffixFileFilter

public static IOFileFilter suffixFileFilter(String suffix)

Returns a filter that returns true if the file name ends with the specified text.

Parameters:

suffix - the file name suffix

Returns:

a suffix checking filter

See Also:

SuffixFileFilter

suffixFileFilter

public static IOFileFilter suffixFileFilter(String suffix,
                                            IOCase ioCase)

Returns a filter that returns true if the file name ends with the specified text.

Parameters:

suffix - the file name suffix

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

Returns:

a suffix checking filter

Since:

2.0

See Also:

SuffixFileFilter

toList

public static List<IOFileFilter> toList(IOFileFilter... filters)

Create a List of file filters.

Parameters:

filters - The file filters

Returns:

The list of file filters

Throws:

NullPointerException - if the filters are null or contain a null value.

Since:

2.0

trueFileFilter

public static IOFileFilter trueFileFilter()

Returns a filter that always returns true.

Returns:

a true filter

See Also:

TrueFileFilter.TRUE