Package org.apache.commons.io.filefilter

Class EmptyFileFilter

java.lang.Object

org.apache.commons.io.filefilter.AbstractFileFilter

org.apache.commons.io.filefilter.EmptyFileFilter

All Implemented Interfaces:

FileFilter, FilenameFilter, Serializable, FileVisitor<Path>, PathMatcher, PathFilter, PathVisitor, IOFileFilter

public class EmptyFileFilter
extends AbstractFileFilter
implements Serializable

This filter accepts files or directories that are empty.

If the File is a directory it checks that it contains no files.

Example, showing how to print out a list of the current directory's empty files/directories:

Using Classic IO

 File dir = FileUtils.current();
 String[] files = dir.list(EmptyFileFilter.EMPTY);
 for (String file : files) {
     System.out.println(file);
 }
 

Example, showing how to print out a list of the current directory's non-empty files/directories:

 File dir = FileUtils.current();
 String[] files = dir.list(EmptyFileFilter.NOT_EMPTY);
 for (String file : files) {
     System.out.println(file);
 }
 

Using NIO

 final Path dir = PathUtils.current();
 final AccumulatorPathVisitor visitor = AccumulatorPathVisitor.withLongCounters(EmptyFileFilter.EMPTY);
 //
 // Walk one directory
 Files.walkFileTree(dir, Collections.emptySet(), 1, visitor);
 System.out.println(visitor.getPathCounters());
 System.out.println(visitor.getFileList());
 //
 visitor.getPathCounters().reset();
 //
 // Walk directory tree
 Files.walkFileTree(dir, visitor);
 System.out.println(visitor.getPathCounters());
 System.out.println(visitor.getDirList());
 System.out.println(visitor.getFileList());
 

Deprecating Serialization

Serialization is deprecated and will be removed in 3.0.

Since:

1.3

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final IOFileFilter	EMPTY	Singleton instance of empty filter
static final IOFileFilter	NOT_EMPTY	Singleton instance of not-empty filter

Fields inherited from interface org.apache.commons.io.filefilter.IOFileFilter

EMPTY_STRING_ARRAY

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	EmptyFileFilter()	Restrictive constructor.

Method Summary

Modifier and Type	Method	Description
boolean	accept(File file)	Checks to see if the file is empty.
FileVisitResult	accept(Path file, BasicFileAttributes attributes)	Checks to see if the file is empty.

Methods inherited from class org.apache.commons.io.filefilter.AbstractFileFilter

accept, handle, postVisitDirectory, preVisitDirectory, toString, visitFile, visitFileFailed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.io.filefilter.IOFileFilter

and, matches, negate, or

Field Details

EMPTY

public static final IOFileFilter EMPTY

Singleton instance of empty filter

NOT_EMPTY

public static final IOFileFilter NOT_EMPTY

Singleton instance of not-empty filter

Constructor Details

EmptyFileFilter

protected EmptyFileFilter()

Restrictive constructor.

Method Details

accept

public boolean accept(File file)

Checks to see if the file is empty.

Specified by:

accept in interface FileFilter

Specified by:

accept in interface IOFileFilter

Overrides:

accept in class AbstractFileFilter

Parameters:

file - the file or directory to check

Returns:

true if the file or directory is empty, otherwise false.

accept

public FileVisitResult accept(Path file,
 BasicFileAttributes attributes)

Checks to see if the file is empty.

Specified by:

accept in interface IOFileFilter

Specified by:

accept in interface PathFilter

Parameters:

file - the file or directory to check

attributes - the path's basic attributes (may be null).

Returns:

true if the file or directory is empty, otherwise false.

Since:

2.9.0