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 and 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 Detail

      • 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>)