Package org.apache.commons.io.filefilter
This package defines an interface (IOFileFilter) that combines both
FileFilter
and FilenameFilter
. Besides
that the package offers a series of ready-to-use implementations of the
IOFileFilter interface including implementation that allow you to combine
other such filters.
These filter can be used to list files or in FileDialog
,
for example.
DirectoryFilter | Only accept directories |
PrefixFileFilter | Filter based on a prefix |
SuffixFileFilter | Filter based on a suffix |
NameFileFilter | Filter based on a filename |
WildcardFileFilter | Filter based on wildcards |
AgeFileFilter | Filter based on last modified time of file |
SizeFileFilter | Filter based on file size |
TrueFileFilter | Accept all files |
FalseFileFilter | Accept no files |
NotFileFilter | Applies a logical NOT to an existing filter |
AndFileFilter | Combines two filters using a logical AND |
OrFileFilter | Combines two filter using a logical OR |
These boolean FilenameFilters can be nested, to allow arbitrary expressions. For example, here is how one could print all non-directory files in the current directory, starting with "A", and ending in ".java" or ".class":
File dir = new File("."); String[] files = dir.list( new AndFileFilter( new AndFileFilter( new PrefixFileFilter("A"), new OrFileFilter( new SuffixFileFilter(".class"), new SuffixFileFilter(".java") ) ), new NotFileFilter( new DirectoryFileFilter() ) ) ); for ( int i=0; i<files.length; i++ ) { System.out.println(files[i]); }
This package also contains a utility class: FileFilterUtils. It allows you to use all file filters without having to put them in the import section. Here's how the above example will look using FileFilterUtils:
File dir = new File("."); String[] files = dir.list( FileFilterUtils.andFileFilter( FileFilterUtils.andFileFilter( FileFilterUtils.prefixFileFilter("A"), FileFilterUtils.orFileFilter( FileFilterUtils.suffixFileFilter(".class"), FileFilterUtils.suffixFileFilter(".java") ) ), FileFilterUtils.notFileFilter( FileFilterUtils.directoryFileFilter() ) ) ); for ( int i=0; i<files.length; i++ ) { System.out.println(files[i]); }
There are a few other goodies in that class so please have a look at the documentation in detail.
-
Interface Summary Interface Description ConditionalFileFilter Defines operations for conditional file filters.IOFileFilter An interface which brings the FileFilter and FilenameFilter interfaces together. -
Class Summary Class Description AbstractFileFilter An abstract class which implements the Java FileFilter and FilenameFilter interfaces via the IOFileFilter interface.AgeFileFilter Filters files based on a cutoff time, can filter either newer files or files equal to or older.AndFileFilter AFileFilter
providing conditional AND logic across a list of file filters.CanExecuteFileFilter This filter acceptsFile
s that can be executed.CanReadFileFilter This filter acceptsFile
s that can be read.CanWriteFileFilter This filter acceptsFile
s that can be written to.DelegateFileFilter This class turns a Java FileFilter or FilenameFilter into an IO FileFilter.DirectoryFileFilter This filter acceptsFile
s that are directories.EmptyFileFilter This filter accepts files or directories that are empty.FalseFileFilter A file filter that always returns false.FileFileFilter This filter acceptsFile
s that are files (not directories).FileFilterUtils Useful utilities for working with file filters.HiddenFileFilter This filter acceptsFile
s that are hidden.MagicNumberFileFilter File filter for matching files containing a "magic number".NameFileFilter Filters file names for a certain name.NotFileFilter This filter produces a logical NOT of the filters specified.OrFileFilter AFileFilter
providing conditional OR logic across a list of file filters.PrefixFileFilter Filters file names for a certain prefix.RegexFileFilter Filters files using supplied regular expression(s).SizeFileFilter Filters files based on size, can filter either smaller files or files equal to or larger than a given threshold.SuffixFileFilter Filters files based on the suffix (what the file name ends with).TrueFileFilter A file filter that always returns true.WildcardFileFilter Filters files using the supplied wildcards.WildcardFilter Deprecated. Use WildcardFileFilter.