The list method (§22.24.26) of class File requires, as an argument, an object
that implements the FilenameFilter interface. The only purpose of such an
object is to provide a method accept that decides which files should appear in the
generated directory listing.
public interfaceFilenameFilter{ public booleanaccept(File dir, String name); }
22.25.1 public boolean accept(File dir, String name)
This method should return true if and only if the given file named name in the
directory dir is to appear in the final list of files generated by the list method
(§22.24.26) of class File.