/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* Defines interfaces and classes for the Java virtual machine to access files,
* file attributes, and file systems.
*
* <p> The java.nio.file package defines classes to access files and file
* systems. The API to access file and file system attributes is defined in the
* {@link java.nio.file.attribute} package. The {@link java.nio.file.spi}
* package is used by service provider implementors wishing to extend the
* platform default provider, or to construct other provider implementations. </p>
*
* <a name="links"><h3>Symbolic Links</h3></a>
* Many operating systems and file systems support for <em>symbolic links</em>.
* A symbolic link is a special file that serves as a reference to another file.
* For the most part, symbolic links are transparent to applications and
* operations on symbolic links are automatically redirected to the <em>target</em>
* of the link. Exceptions to this are when a symbolic link is deleted or
* target of the link. This package includes support for symbolic links where
* implementations provide these semantics. File systems may support other types
* that are semantically close but support for these other types of links is
* not included in this package. </p>
*
* <a name="interop"><h3>Interoperability</h3></a>
* The {@link java.io.File} class defines the {@link java.io.File#toPath
* toPath} method to construct a {@link java.nio.file.Path} by converting
* the abstract path represented by the {@code java.io.File} object. The resulting
* {@code Path} can be used to operate on the same file as the {@code File}
* object. The {@code Path} specification provides further information
* on the <a href="Path.html#interop">interoperability</a> between {@code Path}
* and {@code java.io.File} objects. </p>
*
* <h3>Visibility</h3>
* The view of the files and file system provided by classes in this package are
* guaranteed to be consistent with other views provided by other instances in the
* same Java virtual machine. The view may or may not, however, be consistent with
* the view of the file system as seen by other concurrently running programs due
* to caching performed by the underlying operating system and delays induced by
* network-filesystem protocols. This is true regardless of the language in which
* these other programs are written, and whether they are running on the same machine
* or on some other machine. The exact nature of any such inconsistencies are
* system-dependent and are therefore unspecified. </p>
*
* <a name="integrity"><h3>Synchronized I/O File Integrity</h3></a>
* The {@link java.nio.file.StandardOpenOption#SYNC SYNC} and {@link
* java.nio.file.StandardOpenOption#DSYNC DSYNC} options are used when opening a file
* to require that updates to the file are written synchronously to the underlying
* storage device. In the case of the default provider, and the file resides on
* a local storage device, and the {@link java.nio.channels.SeekableByteChannel
* seekable} channel is connected to a file that was opened with one of these
* options, then an invocation of the {@link
* java.nio.channels.WritableByteChannel#write(java.nio.ByteBuffer) write}
* method is only guaranteed to return when all changes made to the file
* by that invocation have been written to the device. These options are useful
* for ensuring that critical information is not lost in the event of a system
* crash. If the file does not reside on a local device then no such guarantee
* is made. Whether this guarantee is possible with other {@link
* java.nio.file.spi.FileSystemProvider provider} implementations is provider
* specific. </p>
*
* <h3>General Exceptions</h3>
* Unless otherwise noted, passing a {@code null} argument to a constructor
* or method of any class or interface in this package will cause a {@link
* java.lang.NullPointerException NullPointerException} to be thrown. Additionally,
* invoking a method with a collection containing a {@code null} element will
* cause a {@code NullPointerException}, unless otherwise specified. </p>
*
* <p> Unless otherwise noted, methods that attempt to access the file system
* will throw {@link java.nio.file.ClosedFileSystemException} when invoked on
* objects associated with a {@link java.nio.file.FileSystem} that has been
* {@link java.nio.file.FileSystem#close closed}. Additionally, any methods
* that attempt write access to a file system will throw {@link
* java.nio.file.ReadOnlyFileSystemException} when invoked on an object associated
* with a {@link java.nio.file.FileSystem} that only provides read-only
* access. </p>
*
* <p> Unless otherwise noted, invoking a method of any class or interface in
* this package created by one {@link java.nio.file.spi.FileSystemProvider
* provider} with a parameter that is an object created by another provider,
* will throw {@link java.nio.file.ProviderMismatchException}. </p>
*
* <h3>Optional Specific Exceptions</h3>
* Most of the methods defined by classes in this package that access the
* file system specify that {@link java.io.IOException} be thrown when an I/O
* error occurs. In some cases, these methods define specific I/O exceptions
* for common cases. These exceptions, noted as <i>optional specific exceptions</i>,
* are thrown by the implementation where it can detect the specific error.
* Where the specific error cannot be detected then the more general {@code
* IOException} is thrown.
*
* @since 1.7
*/