「已废弃」

Returns the pathname string of this abstract pathname's parent, or
{@code null} if this pathname does not name a parent directory.

The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory.

Returns the abstract pathname of this abstract pathname's parent,
or{@code null} if this pathname does not name a parent
directory.

The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory.

Returns the absolute pathname string of this abstract pathname.

If this abstract pathname is already absolute, then the pathname string is simply returned as if by the{@link #getPath} method. If this abstract pathname is the empty abstract pathname then the pathname string of the current user directory, which is named by the system property{@code user.dir}, is returned. Otherwise this pathname is resolved in a system-dependent way. On UNIX systems, a relative pathname is made absolute by resolving it against the current user directory. On Microsoft Windows systems, a relative pathname is made absolute by resolving it against the current directory of the drive named by the pathname, if any; if not, it is resolved against the current user directory.

Returns the canonical pathname string of this abstract pathname.

A canonical pathname is both absolute and unique. The precise definition of canonical form is system-dependent. This method first converts this pathname to absolute form if necessary, as if by invoking the {@link #getAbsolutePath} method, and then maps it to its unique form in a system-dependent way. This typically involves removing redundant names such as{@code "."} and{@code ".."} from the pathname, resolving symbolic links (on UNIX platforms), and converting drive letters to a standard case (on Microsoft Windows platforms).

Every pathname that denotes an existing file or directory has a unique canonical form. Every pathname that denotes a nonexistent file or directory also has a unique canonical form. The canonical form of the pathname of a nonexistent file or directory may be different from the canonical form of the same pathname after the file or directory is created. Similarly, the canonical form of the pathname of an existing file or directory may be different from the canonical form of the same pathname after the file or directory is deleted.

Tests whether the file denoted by this abstract pathname is a
directory.

Where it is required to distinguish an I/O exception from the case that the file is not a directory, or where several attributes of the same file are required at the same time, then the{@link * java.nio.file.Files#readAttributes(Path,Class,LinkOption[]) * Files.readAttributes} method may be used.

Tests whether the file denoted by this abstract pathname is a normal
file. A file is normal if it is not a directory and, in
addition, satisfies other system-dependent criteria. Any non-directory
file created by a Java application is guaranteed to be a normal file.

Where it is required to distinguish an I/O exception from the case that the file is not a normal file, or where several attributes of the same file are required at the same time, then the{@link * java.nio.file.Files#readAttributes(Path,Class,LinkOption[]) * Files.readAttributes} method may be used.

Sets the last-modified time of the file or directory named by this
abstract pathname.

All platforms support file-modification times to the nearest second, but some provide more precision. The argument will be truncated to fit the supported precision. If the operation succeeds and no intervening operations on the file take place, then the next invocation of the {@link #lastModified} method will return the (possibly truncated){@code time} argument that was passed to this method.

A convenience method to set the owner's write permission for this abstract
pathname. On some platforms it may be possible to start the Java virtual
machine with special privileges that allow it to modify files that
disallow write operations.

An invocation of this method of the form{@code file.setWritable(arg)} behaves in exactly the same way as the invocation

{@code
    *     file.setWritable(arg, true)
    * }

A convenience method to set the owner's read permission for this abstract
pathname. On some platforms it may be possible to start the Java virtual
machine with special privileges that allow it to read files that are
marked as unreadable.

An invocation of this method of the form{@code file.setReadable(arg)} behaves in exactly the same way as the invocation

{@code
    *     file.setReadable(arg, true)
    * }

A convenience method to set the owner's execute permission for this
abstract pathname. On some platforms it may be possible to start the Java
virtual machine with special privileges that allow it to execute files
that are not marked executable.

An invocation of this method of the form{@code file.setExcutable(arg)} behaves in exactly the same way as the invocation

{@code
    *     file.setExecutable(arg, true)
    * }

Returns the number of unallocated bytes in the partition named by this abstract path name. If the
number of unallocated bytes in the partition is greater than
{@link Long#MAX_VALUE}, then{@code Long.MAX_VALUE} will be returned.

The returned number of unallocated bytes is a hint, but not a guarantee, that it is possible to use most or any of these bytes. The number of unallocated bytes is most likely to be accurate immediately after this call. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this virtual machine. This method makes no guarantee that write operations to this file system will succeed.

Returns the number of bytes available to this virtual machine on the
partition named by this abstract pathname. If
the number of available bytes in the partition is greater than
{@link Long#MAX_VALUE}, then{@code Long.MAX_VALUE} will be returned.
When possible, this method checks for write permissions and other
operating system restrictions and will therefore usually provide a more
accurate estimate of how much new data can actually be written than
{@link #getFreeSpace}.

The returned number of available bytes is a hint, but not a guarantee, that it is possible to use most or any of these bytes. The number of available bytes is most likely to be accurate immediately after this call. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this virtual machine. This method makes no guarantee that write operations to this file system will succeed.