Module java.base

Package java.nio.file.attribute

Interface BasicFileAttributes

All Known Subinterfaces:

DosFileAttributes, PosixFileAttributes

public interface BasicFileAttributes

Basic attributes associated with a file in a file system.

Basic file attributes are attributes that are common to many file systems and consist of mandatory and optional file attributes as defined by this interface.

Usage Example:

    Path file = ...
    BasicFileAttributes attrs = Files.readAttributes(file, BasicFileAttributes.class);

Since:

1.7

See Also:

• BasicFileAttributeView

Method Summary

Modifier and Type	Method	Description
FileTime	creationTime()	Returns the creation time.
Object	fileKey()	Returns an object that uniquely identifies the given file, or null if a file key is not available.
boolean	isDirectory()	Tells whether the file is a directory.
boolean	isOther()	Tells whether the file is something other than a regular file, directory, or symbolic link.
boolean	isRegularFile()	Tells whether the file is a regular file with opaque content.
boolean	isSymbolicLink()	Tells whether the file is a symbolic link.
FileTime	lastAccessTime()	Returns the time of last access.
FileTime	lastModifiedTime()	Returns the time of last modification.
long	size()	Returns the size of the file (in bytes).

Method Details

lastModifiedTime

FileTime lastModifiedTime()

Returns the time of last modification.

If the file system implementation does not support a time stamp to indicate the time of last modification then this method returns an implementation specific default value, typically a FileTime representing the epoch (1970-01-01T00:00:00Z).

Returns:

a FileTime representing the time the file was last modified

lastAccessTime

FileTime lastAccessTime()

Returns the time of last access.

If the file system implementation does not support a time stamp to indicate the time of last access then this method returns an implementation specific default value, typically the last-modified-time or a FileTime representing the epoch (1970-01-01T00:00:00Z).

Returns:

a FileTime representing the time of last access

creationTime

FileTime creationTime()

Returns the creation time. The creation time is the time that the file was created.

If the file system implementation does not support a time stamp to indicate the time when the file was created then this method returns an implementation specific default value, typically the last-modified-time or a FileTime representing the epoch (1970-01-01T00:00:00Z).

Returns:

a FileTime representing the time the file was created

isRegularFile

boolean isRegularFile()

Tells whether the file is a regular file with opaque content.

Returns:

true if the file is a regular file with opaque content

isDirectory

boolean isDirectory()

Tells whether the file is a directory.

Returns:

true if the file is a directory

isSymbolicLink

boolean isSymbolicLink()

Tells whether the file is a symbolic link.

Returns:

true if the file is a symbolic link

isOther

boolean isOther()

Tells whether the file is something other than a regular file, directory, or symbolic link.

Returns:

true if the file something other than a regular file, directory or symbolic link

size

long size()

Returns the size of the file (in bytes). The size may differ from the actual size on the file system due to compression, support for sparse files, or other reasons. The size of files that are not regular files is implementation specific and therefore unspecified.

Returns:

the file size, in bytes

fileKey

Object fileKey()

Returns an object that uniquely identifies the given file, or null if a file key is not available. On some platforms or file systems it is possible to use an identifier, or a combination of identifiers to uniquely identify a file. Such identifiers are important for operations such as file tree traversal in file systems that support symbolic links or file systems that allow a file to be an entry in more than one directory. On UNIX file systems, for example, the device ID and inode are commonly used for such purposes.

The file key returned by this method can only be guaranteed to be unique if the file system and files remain static. Whether a file system re-uses identifiers after a file is deleted is implementation dependent and therefore unspecified.

File keys returned by this method can be compared for equality and are suitable for use in collections. If the file system and files remain static, and two files are the same with non-null file keys, then their file keys are equal.

Returns:

an object that uniquely identifies the given file, or null

See Also:

• Files.walkFileTree(java.nio.file.Path, java.util.Set<java.nio.file.FileVisitOption>, int, java.nio.file.FileVisitor<? super java.nio.file.Path>)