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 dir
 Files.walkFileTree(dir, Collections.emptySet(), 1, visitor);
 System.out.println(visitor.getPathCounters());
 System.out.println(visitor.getFileList());
 //
 visitor.getPathCounters().reset();
 //
 // Walk dir 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:

  • 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

    • serialVersionUID

      private static final long serialVersionUID
      See Also:

  • 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 file's basic attributes (TODO may be null).
      Returns:
      true if the file or directory is empty, otherwise false.
      Since:
      2.9.0