--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/nio/file/Path.java Sun Feb 15 12:25:54 2009 +0000
@@ -0,0 +1,1612 @@
+/*
+ * Copyright 2007-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.nio.file;
+
+import java.nio.file.attribute.*;
+import java.nio.channels.*;
+import java.io.*;
+import java.net.URI;
+import java.util.*;
+
+/**
+ * A file reference that locates a file using a system dependent path. The file
+ * is not required to exist.
+ *
+ * <p> On many platforms a <em>path</em> is the means to locate and access files
+ * in a file system. A path is hierarchical and composed of a sequence of
+ * directory names separated by a special separator or delimiter.
+ *
+ * <h4>Path operations</h4>
+ *
+ * <p> A system dependent path represented by this class is conceptually a
+ * sequence of name elements and optionally a <em>root component</em>. The name
+ * that is <em>farthest</em> from the root of the directory hierarchy is the
+ * name of a file or directory. The other elements are directory names. The root
+ * component typically identifies a file system hierarchy. A {@code Path} can
+ * represent a root, a root and a sequence of names, or simply one or more name
+ * elements. It defines the {@link #getName() getName}, {@link #getParent
+ * getParent}, {@link #getRoot getRoot}, and {@link #subpath subpath} methods
+ * to access the components or a subsequence of its name elements.
+ *
+ * <p> In addition to accessing the components of a path, a {@code Path} also
+ * defines {@link #resolve(Path) resolve} and {@link #relativize relativize}
+ * operations. Paths can also be {@link #compareTo compared}, and tested
+ * against each other using using the {@link #startsWith startsWith} and {@link
+ * #endsWith endWith} methods.
+ *
+ * <h4>File operations</h4>
+ *
+ * <p> A {@code Path} is either <em>absolute</em> or <em>relative</em>. An
+ * absolute path is complete in that does not need to be combined with another
+ * path in order to locate a file. All operations on relative paths are first
+ * resolved against a file system's default directory as if by invoking the
+ * {@link #toAbsolutePath toAbsolutePath} method.
+ *
+ * <p> In addition to the operations defined by the {@link FileRef} interface,
+ * this class defines the following operations:
+ *
+ * <ul>
+ * <li><p> Files may be {@link #createFile(FileAttribute[]) created}, or
+ * directories may be {@link #createDirectory(FileAttribute[]) created}.
+ * </p></li>
+ * <li><p> Directories can be {@link #newDirectoryStream opened} so as to
+ * iterate over the entries in the directory. </p></li>
+ * <li><p> Files can be {@link #copyTo(Path,CopyOption[]) copied} or
+ * {@link #moveTo(Path,CopyOption[]) moved}. </p></li>
+ * <li><p> Symbolic-links may be {@link #createSymbolicLink created}, or the
+ * target of a link may be {@link #readSymbolicLink read}. </p></li>
+ * <li><p> {@link #newInputStream InputStream} or {@link #newOutputStream
+ * OutputStream} streams can be created to allow for interoperation with the
+ * <a href="../../../java/io/package-summary.html">{@code java.io}</a> package
+ * where required. </li></p>
+ * <li><p> The {@link #toRealPath real} path of an existing file may be
+ * obtained. </li></p>
+ * </ul>
+ *
+ * <p> This class implements {@link Watchable} interface so that a directory
+ * located by a path can be {@link #register registered} with a {@link WatchService}.
+ * and entries in the directory watched.
+ *
+ * <h4>File attributes</h4>
+ *
+ * The <a href="attribute/package-summary.html">{@code java.nio.file.attribute}</a>
+ * package provides access to file attributes or <em>meta-data</em> associated
+ * with files. The {@link Attributes Attributes} class defines methods that
+ * operate on or return file attributes. For example, the file type, size,
+ * timestamps, and other <em>basic</em> meta-data are obtained, in bulk, by
+ * invoking the {@link Attributes#readBasicFileAttributes
+ * Attributes.readBasicFileAttributes} method:
+ * <pre>
+ * Path file = ...
+ * BasicFileAttributes attrs = Attributes.readBasicFileAttributes(file);
+ * </pre>
+ *
+ * <a name="interop"><h4>Interoperability</h4></a>
+ *
+ * <p> Paths created by file systems associated with the default {@link
+ * java.nio.file.spi.FileSystemProvider provider} are generally interoperable
+ * with the {@link java.io.File java.io.File} class. Paths created by other
+ * providers are unlikely to be interoperable with the abstract path names
+ * represented by {@code java.io.File}. The {@link java.io.File#toPath
+ * File.toPath} method may be used to obtain a {@code Path} from the abstract
+ * path name represented by a {@code java.io.File java.io.File} object. The
+ * resulting {@code Path} can be used to operate on the same file as the {@code
+ * java.io.File} object.
+ *
+ * <p> Path objects created by file systems associated with the default
+ * provider are interoperable with objects created by other file systems created
+ * by the same provider. Path objects created by file systems associated with
+ * other providers may not be interoperable with other file systems created by
+ * the same provider. The reasons for this are provider specific.
+ *
+ * <h4>Concurrency</h4></a>
+ *
+ * <p> Instances of this class are immutable and safe for use by multiple concurrent
+ * threads.
+ *
+ * @since 1.7
+ */
+
+public abstract class Path
+ implements FileRef, Comparable<Path>, Iterable<Path>, Watchable
+{
+ /**
+ * Initializes a new instance of this class.
+ */
+ protected Path() { }
+
+ /**
+ * Returns the file system that created this object.
+ *
+ * @return The file system that created this object
+ */
+ public abstract FileSystem getFileSystem();
+
+ /**
+ * Tells whether or not this path is absolute.
+ *
+ * <p> An absolute path is complete in that it doesn't need to be
+ * combined with other path information in order to locate a file.
+ *
+ * @return {@code true} if, and only if, this path is absolute
+ */
+ public abstract boolean isAbsolute();
+
+ /**
+ * Returns the root component of this path as a {@code Path} object,
+ * or {@code null} if this path does not have a root component.
+ *
+ * @return A path representing the root component of this path,
+ * or {@code null}
+ */
+ public abstract Path getRoot();
+
+ /**
+ * Returns the name of the file or directory denoted by this path. The
+ * file name is the <em>farthest</em> element from the root in the directory
+ * hierarchy.
+ *
+ * @return A path representing the name of the file or directory, or
+ * {@code null} if this path has zero elements
+ */
+ public abstract Path getName();
+
+ /**
+ * Returns the <em>parent path</em>, or {@code null} if this path does not
+ * have a parent.
+ *
+ * <p> The parent of this path object consists of this path's root
+ * component, if any, and each element in the path except for the
+ * <em>farthest</em> from the root in the directory hierarchy. This method
+ * does not access the file system; the path or its parent may not exist.
+ * Furthermore, this method does not eliminate special names such as "."
+ * and ".." that may be used in some implementations. On UNIX for example,
+ * the parent of "{@code /a/b/c}" is "{@code /a/b}", and the parent of
+ * {@code "x/y/.}" is "{@code x/y}". This method may be used with the {@link
+ * #normalize normalize} method, to eliminate redundant names, for cases where
+ * <em>shell-like</em> navigation is required.
+ *
+ * <p> If this path has one or more elements, and no root component, then
+ * this method is equivalent to evaluating the expression:
+ * <blockquote><pre>
+ * subpath(0, getNameCount()-1);
+ * </pre></blockquote>
+ *
+ * @return A path representing the path's parent
+ */
+ public abstract Path getParent();
+
+ /**
+ * Returns the number of name elements in the path.
+ *
+ * @return The number of elements in the path, or {@code 0} if this path
+ * only represents a root component
+ */
+ public abstract int getNameCount();
+
+ /**
+ * Returns a name element of this path.
+ *
+ * <p> The {@code index} parameter is the index of the name element to return.
+ * The element that is <em>closest</em> to the root in the directory hierarchy
+ * has index {@code 0}. The element that is <em>farthest</em> from the root
+ * has index {@link #getNameCount count}{@code -1}.
+ *
+ * @param index
+ * The index of the element
+ *
+ * @return The name element
+ *
+ * @throws IllegalArgumentException
+ * If {@code index} is negative, {@code index} is greater than or
+ * equal to the number of elements, or this path has zero name
+ * elements.
+ */
+ public abstract Path getName(int index);
+
+ /**
+ * Returns a relative {@code Path} that is a subsequence of the name
+ * elements of this path.
+ *
+ * <p> The {@code beginIndex} and {@code endIndex} parameters specify the
+ * subsequence of name elements. The name that is <em>closest</em> to the root
+ * in the directory hierarchy has index {@code 0}. The name that is
+ * <em>farthest</em> from the root has index {@link #getNameCount
+ * count}{@code -1}. The returned {@code Path} object has the name elements
+ * that begin at {@code beginIndex} and extend to the element at index {@code
+ * endIndex-1}.
+ *
+ * @param beginIndex
+ * The index of the first element, inclusive
+ * @param endIndex
+ * The index of the last element, exclusive
+ *
+ * @return A new {@code Path} object that is a subsequence of the name
+ * elements in this {@code Path}
+ *
+ * @throws IllegalArgumentException
+ * If {@code beginIndex} is negative, or greater than or equal to
+ * the number of elements. If {@code endIndex} is less than or
+ * equal to {@code beginIndex}, or larger than the number of elements.
+ */
+ public abstract Path subpath(int beginIndex, int endIndex);
+
+ /**
+ * Tests if this path starts with the given path.
+ *
+ * <p> This path <em>starts</em> with the given path if this path's root
+ * component <em>starts</em> with the root component of the given path,
+ * and this path starts with the same name elements as the given path.
+ * If the given path has more name elements than this path then {@code false}
+ * is returned.
+ *
+ * <p> Whether or not the root component of this path starts with the root
+ * component of the given path is file system specific. If this path does
+ * not have a root component and the given path has a root component then
+ * this path does not start with the given path.
+ *
+ * @param other
+ * The given path
+ *
+ * @return {@code true} if this path starts with the given path; otherwise
+ * {@code false}
+ */
+ public abstract boolean startsWith(Path other);
+
+ /**
+ * Tests if this path ends with the given path.
+ *
+ * <p> If the given path has <em>N</em> elements, and no root component,
+ * and this path has <em>N</em> or more elements, then this path ends with
+ * the given path if the last <em>N</em> elements of each path, starting at
+ * the element farthest from the root, are equal.
+ *
+ * <p> If the given path has a root component then this path ends with the
+ * given path if the root component of this path <em>ends with</em> the root
+ * component of the given path, and the corresponding elements of both paths
+ * are equal. Whether or not the root component of this path ends with the
+ * root component of the given path is file system specific. If this path
+ * does not have a root component and the given path has a root component
+ * then this path does not end with the given path.
+ *
+ * @param other
+ * The given path
+ *
+ * @return {@code true} if this path ends with the given path; otherwise
+ * {@code false}
+ */
+ public abstract boolean endsWith(Path other);
+
+ /**
+ * Returns a path that is this path with redundant name elements eliminated.
+ *
+ * <p> The precise definition of this method is implementation dependent but
+ * in general it derives from this path, a path that does not contain
+ * <em>redundant</em> name elements. In many file systems, the "{@code .}"
+ * and "{@code ..}" are special names used to indicate the current directory
+ * and parent directory. In such file systems all occurrences of "{@code .}"
+ * are considered redundant. If a "{@code ..}" is preceded by a
+ * non-"{@code ..}" name then both names are considered redundant (the
+ * process to identify such names is repeated until is it no longer
+ * applicable).
+ *
+ * <p> This method does not access the file system; the path may not locate
+ * a file that exists. Eliminating "{@code ..}" and a preceding name from a
+ * path may result in the path that locates a different file than the original
+ * path. This can arise when the preceding name is a symbolic link.
+ *
+ * @return The resulting path, or this path if it does not contain
+ * redundant name elements, or {@code null} if this path does not
+ * have a root component and all name elements are redundant.
+ *
+ * @see #getParent
+ * @see #toRealPath
+ */
+ public abstract Path normalize();
+
+ // -- resolution and relativization --
+
+ /**
+ * Resolve the given path against this path.
+ *
+ * <p> If the {@code other} parameter is an {@link #isAbsolute() absolute}
+ * path then this method trivially returns {@code other}. If {@code other}
+ * is {@code null} then this path is returned. Otherwise this method
+ * considers this path to be a directory and resolves the given path
+ * against this path. In the simplest case, the given path does not have
+ * a {@link #getRoot root} component, in which case this method <em>joins</em>
+ * the given path to this path and returns a resulting path that {@link
+ * #endsWith ends} with the given path. Where the given path has a root
+ * component then resolution is highly implementation dependent and therefore
+ * unspecified.
+ *
+ * @param other
+ * The path to resolve against this path; can be {@code null}
+ *
+ * @return The resulting path
+ *
+ * @see #relativize
+ */
+ public abstract Path resolve(Path other);
+
+ /**
+ * Converts a given path string to a {@code Path} and resolves it against
+ * this {@code Path} in exactly the manner specified by the {@link
+ * #resolve(Path) resolve} method.
+ *
+ * @param other
+ * The path string to resolve against this path
+ *
+ * @return The resulting path
+ *
+ * @throws InvalidPathException
+ * If the path string cannot be converted to a Path.
+ *
+ * @see FileSystem#getPath
+ */
+ public abstract Path resolve(String other);
+
+ /**
+ * Constructs a relative path between this path and a given path.
+ *
+ * <p> Relativization is the inverse of {@link #resolve(Path) resolution}.
+ * This method attempts to construct a {@link #isAbsolute relative} path
+ * that when {@link #resolve(Path) resolved} against this path, yields a
+ * path that locates the same file as the given path. For example, on UNIX,
+ * if this path is {@code "/a/b"} and the given path is {@code "/a/b/c/d"}
+ * then the resulting relative path would be {@code "c/d"}. Where this
+ * path and the given path do not have a {@link #getRoot root} component,
+ * then a relative path can be constructed. A relative path cannot be
+ * constructed if only one of the paths have a root component. Where both
+ * paths have a root component then it is implementation dependent if a
+ * relative path can be constructed. If this path and the given path are
+ * {@link #equals equal} then {@code null} is returned.
+ *
+ * <p> For any two paths <i>p</i> and <i>q</i>, where <i>q</i> does not have
+ * a root component,
+ * <blockquote>
+ * <i>p</i><tt>.relativize(</tt><i>p</i><tt>.resolve(</tt><i>q</i><tt>)).equals(</tt><i>q</i><tt>)</tt>
+ * </blockquote>
+ *
+ * <p> When symbolic-links are supported, then whether the resulting path,
+ * when resolved against this path, yields a path that can be used to locate
+ * the {@link #isSameFile same} file as {@code other} is implementation
+ * dependent. For example, if this path is {@code "/a/b"} and the given
+ * path is {@code "/a/x"} then the resulting relative path may be {@code
+ * "../x"}. If {@code "b"} is a symbolic-link then is implementation
+ * dependent if {@code "a/b/../x"} would locate the same file as {@code "/a/x"}.
+ *
+ * @param other
+ * The resulting path
+ *
+ * @return The resulting relative path, or {@code null} if both paths are
+ * equal
+ *
+ * @throws IllegalArgumentException
+ * If {@code other} is not a {@code Path} that can be relativized
+ * against this path
+ */
+ public abstract Path relativize(Path other);
+
+ // -- file operations --
+
+ /**
+ * Deletes the file located by this path.
+ *
+ * <p> The {@code failIfNotExists} parameter determines how the method
+ * behaves when the file does not exist. When {@code true}, and the file
+ * does not exist, then the method fails. When {@code false} then the method
+ * does not fail.
+ *
+ * <p> As with the {@link FileRef#delete delete()} method, an implementation
+ * may require to examine the file to determine if the file is a directory.
+ * Consequently this method may not be atomic with respect to other file
+ * system operations. If the file is a symbolic-link then the link is
+ * deleted and not the final target of the link.
+ *
+ * <p> If the file is a directory then the directory must be empty. In some
+ * implementations a directory has entries for special files or links that
+ * are created when the directory is created. In such implementations a
+ * directory is considered empty when only the special entries exist.
+ *
+ * <p> On some operating systems it may not be possible to remove a file when
+ * it is open and in use by this Java virtual machine or other programs.
+ *
+ * @param failIfNotExists
+ * {@code true} if the method should fail when the file does not
+ * exist
+ *
+ * @throws NoSuchFileException
+ * If the value of the {@code failIfNotExists} is {@code true} and
+ * the file does not exist <i>(optional specific exception)</i>
+ * @throws DirectoryNotEmptyException
+ * If the file is a directory and could not otherwise be deleted
+ * because the directory is not empty <i>(optional specific
+ * exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkDelete(String)} method
+ * is invoked to check delete access to the file
+ */
+ public abstract void delete(boolean failIfNotExists) throws IOException;
+
+ /**
+ * Creates a symbolic link to a target <i>(optional operation)</i>.
+ *
+ * <p> The {@code target} parameter is the target of the link. It may be an
+ * {@link Path#isAbsolute absolute} or relative path and may not exist. When
+ * the target is a relative path then file system operations on the resulting
+ * link are relative to the path of the link.
+ *
+ * <p> The {@code attrs} parameter is an optional array of {@link FileAttribute
+ * attributes} to set atomically when creating the link. Each attribute is
+ * identified by its {@link FileAttribute#name name}. If more than one attribute
+ * of the same name is included in the array then all but the last occurrence
+ * is ignored.
+ *
+ * <p> Where symbolic links are supported, but the underlying {@link FileStore}
+ * does not support symbolic links, then this may fail with an {@link
+ * IOException}. Additionally, some operating systems may require that the
+ * Java virtual machine be started with implementation specific privileges to
+ * create symbolic links, in which case this method may throw {@code IOException}.
+ *
+ * @param target
+ * The target of the link
+ * @param attrs
+ * The array of attributes to set atomically when creating the
+ * symbolic link
+ *
+ * @return this path
+ *
+ * @throws UnsupportedOperationException
+ * If the implementation does not support symbolic links or the
+ * array contains an attribute that cannot be set atomically when
+ * creating the symbolic link
+ * @throws FileAlreadyExistsException
+ * If a file with the name already exists <i>(optional specific
+ * exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, it denies {@link LinkPermission}<tt>("symbolic")</tt>
+ * or its {@link SecurityManager#checkWrite(String) checkWrite}
+ * method denies write access to the path of the symbolic link.
+ */
+ public abstract Path createSymbolicLink(Path target, FileAttribute<?>... attrs)
+ throws IOException;
+
+ /**
+ * Creates a new link (directory entry) for an existing file <i>(optional
+ * operation)</i>.
+ *
+ * <p> This path locates the directory entry to create. The {@code existing}
+ * parameter is the path to an existing file. This method creates a new
+ * directory entry for the file so that it can be accessed using this path.
+ * On some file systems this is known as creating a "hard link". Whether the
+ * file attributes are maintained for the file or for each directory entry
+ * is file system specific and therefore not specified. Typically, a file
+ * system requires that all links (directory entries) for a file be on the
+ * same file system. Furthermore, on some platforms, the Java virtual machine
+ * may require to be started with implementation specific privileges to
+ * create hard links or to create links to directories.
+ *
+ * @param existing
+ * A reference to an existing file
+ *
+ * @return this path
+ *
+ * @throws UnsupportedOperationException
+ * If the implementation does not support adding an existing file
+ * to a directory
+ * @throws FileAlreadyExistsException
+ * If the entry could not otherwise be created because a file of
+ * that name already exists <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, it denies {@link LinkPermission}<tt>("hard")</tt>
+ * or its {@link SecurityManager#checkWrite(String) checkWrite}
+ * method denies write access to both this path and the path of the
+ * existing file
+ *
+ * @see BasicFileAttributes#linkCount
+ */
+ public abstract Path createLink(Path existing) throws IOException;
+
+ /**
+ * Reads the target of a symbolic link <i>(optional operation)</i>.
+ *
+ * <p> If the file system supports <a href="package-summary.html#links">symbolic
+ * links</a> then this method is used read the target of the link, failing
+ * if the file is not a link. The target of the link need not exist. The
+ * returned {@code Path} object will be associated with the same file
+ * system as this {@code Path}.
+ *
+ * @return A {@code Path} object representing the target of the link
+ *
+ * @throws UnsupportedOperationException
+ * If the implementation does not support symbolic links
+ * @throws NotLinkException
+ * If the target could otherwise not be read because the file
+ * is not a link <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, it checks that {@code FilePermission} has been
+ * granted with the "{@code readlink}" action to read the link.
+ */
+ public abstract Path readSymbolicLink() throws IOException;
+
+ /**
+ * Returns a URI to represent this path.
+ *
+ * <p> This method constructs a hierarchical {@link URI} that is absolute
+ * with a non-empty path component. Its {@link URI#getScheme() scheme} is
+ * equal to the URI scheme that identifies the provider. The exact form of
+ * the other URI components is highly provider dependent. In particular, it
+ * is implementation dependent if its query, fragment, and authority
+ * components are defined or undefined.
+ *
+ * <p> For the default provider the {@link URI#getPath() path} component
+ * will represent the {@link #toAbsolutePath absolute} path; the query,
+ * fragment components are undefined. Whether the authority component is
+ * defined or not is implementation dependent. There is no guarantee that
+ * the {@code URI} may be used to construct a {@link java.io.File java.io.File}.
+ * In particular, if this path represents a Universal Naming Convention (UNC)
+ * path, then the UNC server name may be encoded in the authority component
+ * of the resulting URI. In the case of the default provider, and the file
+ * exists, and it can be determined that the file is a directory, then the
+ * resulting {@code URI} will end with a slash.
+ *
+ * <p> The default provider provides a similar <em>round-trip</em> guarantee
+ * to the {@link java.io.File} class. For a given {@code Path} <i>p</i> it
+ * is guaranteed that
+ * <blockquote><tt>
+ * {@link Paths#get(URI) Paths.get}(</tt><i>p</i><tt>.toUri()).equals(</tt><i>p</i>
+ * <tt>.{@link #toAbsolutePath() toAbsolutePath}())</tt>
+ * </blockquote>
+ * so long as the original {@code Path}, the {@code URI}, and the new {@code
+ * Path} are all created in (possibly different invocations of) the same
+ * Java virtual machine. Whether other providers make any guarantees is
+ * provider specific and therefore unspecified.
+ *
+ * <p> When a file system is constructed to access the contents of a file
+ * as a file system then it is highly implementation specific if the returned
+ * URI represents the given path in the file system or it represents a
+ * <em>compound</em> URI that encodes the URI of the enclosing file system.
+ * A format for compound URIs is not defined in this release; such a scheme
+ * may be added in a future release.
+ *
+ * @return An absolute, hierarchical URI with a non-empty path component
+ *
+ * @throws IOError
+ * If an I/O error occurs obtaining the absolute path, or where a
+ * file system is constructed to access the contents of a file as
+ * a file system, the URI of the enclosing file system cannot be
+ * obtained.
+ *
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, the {@link #toAbsolutePath toAbsolutePath} method
+ * throws a security exception.
+ */
+ public abstract URI toUri();
+
+ /**
+ * Returns a {@code Path} object representing the absolute path of this
+ * path.
+ *
+ * <p> If this path is already {@link Path#isAbsolute absolute} then this
+ * method simply returns this path. Otherwise, this method resolves the path
+ * in an implementation dependent manner, typically by resolving the path
+ * against a file system default directory. Depending on the implementation,
+ * this method may throw an I/O error if the file system is not accessible.
+ *
+ * @return A {@code Path} object representing the absolute path
+ *
+ * @throws IOError
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, its {@link SecurityManager#checkPropertyAccess(String)
+ * checkPropertyAccess} method is invoked to check access to the
+ * system property {@code user.dir}
+ */
+ public abstract Path toAbsolutePath();
+
+ /**
+ * Returns the <em>real</em> path of an existing file.
+ *
+ * <p> The precise definition of this method is implementation dependent but
+ * in general it derives from this path, an {@link #isAbsolute absolute}
+ * path that locates the {@link #isSameFile same} file as this path, but
+ * with name elements that represent the actual name of the directories
+ * and the file. For example, where filename comparisons on a file system
+ * are case insensitive then the name elements represent the names in their
+ * actual case. Additionally, the resulting path has redundant name
+ * elements removed.
+ *
+ * <p> If this path is relative then its absolute path is first obtained,
+ * as if by invoking the {@link #toAbsolutePath toAbsolutePath} method.
+ *
+ * <p> The {@code resolveLinks} parameter specifies if symbolic links
+ * should be resolved. This parameter is ignored when symbolic links are
+ * not supported. Where supported, and the parameter has the value {@code
+ * true} then symbolic links are resolved to their final target. Where the
+ * parameter has the value {@code false} then this method does not resolve
+ * symbolic links. Some implementations allow special names such as
+ * "{@code ..}" to refer to the parent directory. When deriving the <em>real
+ * path</em>, and a "{@code ..}" (or equivalent) is preceded by a
+ * non-"{@code ..}" name then an implementation will typically causes both
+ * names to be removed. When not resolving symbolic links and the preceding
+ * name is a symbolic link then the names are only removed if it guaranteed
+ * that the resulting path will locate the same file as this path.
+ *
+ * @return An absolute path represent the <em>real</em> path of the file
+ * located by this object
+ *
+ * @throws IOException
+ * If the file does not exist or an I/O error occurs
+ * @throws SecurityException
+ * In the case of the the default provider, and a security manager
+ * is installed, its {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the file, and where
+ * this path is not absolute, its {@link SecurityManager#checkPropertyAccess(String)
+ * checkPropertyAccess} method is invoked to check access to the
+ * system property {@code user.dir}
+ */
+ public abstract Path toRealPath(boolean resolveLinks) throws IOException;
+
+ /**
+ * Copy the file located by this path to a target location.
+ *
+ * <p> This method copies the file located by this {@code Path} to the
+ * target location with the {@code options} parameter specifying how the
+ * copy is performed. By default, the copy fails if the target file already
+ * exists, except if the source and target are the {@link #isSameFile same}
+ * file, in which case this method has no effect. File attributes are not
+ * required to be copied to the target file. If symbolic links are supported,
+ * and the file is a link, then the final target of the link is copied. If
+ * the file is a directory then it creates an empty directory in the target
+ * location (entries in the directory are not copied). This method can be
+ * used with the {@link Files#walkFileTree Files.walkFileTree} utility
+ * method to copy a directory and all entries in the directory, or an entire
+ * <i>file-tree</i> where required.
+ *
+ * <p> The {@code options} parameter is an array of options and may contain
+ * any of the following:
+ *
+ * <table border=1 cellpadding=5 summary="">
+ * <tr> <th>Option</th> <th>Description</th> </tr>
+ * <tr>
+ * <td> {@link StandardCopyOption#REPLACE_EXISTING REPLACE_EXISTING} </td>
+ * <td> If the target file exists, then the target file is replaced if it
+ * is not a non-empty directory. If the target file exists and is a
+ * symbolic-link then the symbolic-link is replaced (not the target of
+ * the link. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link StandardCopyOption#COPY_ATTRIBUTES COPY_ATTRIBUTES} </td>
+ * <td> Attempts to copy the file attributes associated with this file to
+ * the target file. The exact file attributes that are copied is platform
+ * and file system dependent and therefore unspecified. Minimally, the
+ * {@link BasicFileAttributes#lastModifiedTime last-modified-time} is
+ * copied to the target file. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link LinkOption#NOFOLLOW_LINKS NOFOLLOW_LINKS} </td>
+ * <td> Symbolic-links are not followed. If the file, located by this path,
+ * is a symbolic-link then the link is copied rather than the target of
+ * the link. It is implementation specific if file attributes can be
+ * copied to the new link. In other words, the {@code COPY_ATTRIBUTES}
+ * option may be ignored when copying a link. </td>
+ * </tr>
+ * </table>
+ *
+ * <p> An implementation of this interface may support additional
+ * implementation specific options.
+ *
+ * <p> Copying a file is not an atomic operation. If an {@link IOException}
+ * is thrown then it possible that the target file is incomplete or some of
+ * its file attributes have not been copied from the source file. When the
+ * {@code REPLACE_EXISTING} option is specified and the target file exists,
+ * then the target file is replaced. The check for the existence of the file
+ * and the creation of the new file may not be atomic with respect to other
+ * file system activities.
+ *
+ * @param target
+ * The target location
+ * @param options
+ * Options specifying how the copy should be done
+ *
+ * @return The target
+ *
+ * @throws UnsupportedOperationException
+ * If the array contains a copy option that is not supported
+ * @throws FileAlreadyExistsException
+ * The target file exists and cannot be replaced because the
+ * {@code REPLACE_EXISTING} option is not specified, or the target
+ * file is a non-empty directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the source file, the
+ * {@link SecurityManager#checkWrite(String) checkWrite} is invoked
+ * to check write access to the target file. If a symbolic link is
+ * copied the security manager is invoked to check {@link
+ * LinkPermission}{@code ("symbolic")}.
+ */
+ public abstract Path copyTo(Path target, CopyOption... options)
+ throws IOException;
+
+ /**
+ * Move or rename the file located by this path to a target location.
+ *
+ * <p> By default, this method attempts to move the file to the target
+ * location, failing if the target file exists except if the source and
+ * target are the {@link #isSameFile same} file, in which case this method
+ * has no effect. If the file is a symbolic link then the link is moved and
+ * not the target of the link. This method may be invoked to move an empty
+ * directory. In some implementations a directory has entries for special
+ * files or links that are created when the directory is created. In such
+ * implementations a directory is considered empty when only the special
+ * entries exist. When invoked to move a directory that is not empty then the
+ * directory is moved if it does not require moving the entries in the directory.
+ * For example, renaming a directory on the same {@link FileStore} will usually
+ * not require moving the entries in the directory. When moving a directory
+ * requires that its entries be moved then this method fails (by throwing
+ * an {@code IOException}). To move a <i>file tree</i> may involve copying
+ * rather than moving directories and this can be done using the {@link
+ * #copyTo copyTo} method in conjunction with the {@link
+ * Files#walkFileTree Files.walkFileTree} utility method.
+ *
+ * <p> The {@code options} parameter is an array of options and may contain
+ * any of the following:
+ *
+ * <table border=1 cellpadding=5 summary="">
+ * <tr> <th>Option</th> <th>Description</th> </tr>
+ * <tr>
+ * <td> {@link StandardCopyOption#REPLACE_EXISTING REPLACE_EXISTING} </td>
+ * <td> If the target file exists, then the target file is replaced if it
+ * is not a non-empty directory. If the target file exists and is a
+ * symbolic-link then the symbolic-link is replaced and not the target of
+ * the link. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link StandardCopyOption#ATOMIC_MOVE ATOMIC_MOVE} </td>
+ * <td> The move is performed as an atomic file system operation and all
+ * other options are ignored. If the target file exists then it is
+ * implementation specific if the existing file is replaced or this method
+ * fails by throwing an {@link IOException}. If the move cannot be
+ * performed as an atomic file system operation then {@link
+ * AtomicMoveNotSupportedException} is thrown. This can arise, for
+ * example, when the target location is on a different {@code FileStore}
+ * and would require that the file be copied, or target location is
+ * associated with a different provider to this object. </td>
+ * </table>
+ *
+ * <p> An implementation of this interface may support additional
+ * implementation specific options.
+ *
+ * <p> Where the move requires that the file be copied then the {@link
+ * BasicFileAttributes#lastModifiedTime last-modified-time} is copied to the
+ * new file. An implementation may also attempt to copy other file
+ * attributes but is not required to fail if the file attributes cannot be
+ * copied. When the move is performed as a non-atomic operation, and a {@code
+ * IOException} is thrown, then the state of the files is not defined. The
+ * original file and the target file may both exist, the target file may be
+ * incomplete or some of its file attributes may not been copied from the
+ * original file.
+ *
+ * @param target
+ * The target location
+ * @param options
+ * Options specifying how the move should be done
+ *
+ * @return The target
+ *
+ * @throws UnsupportedOperationException
+ * If the array contains a copy option that is not supported
+ * @throws FileAlreadyExistsException
+ * The target file exists and cannot be replaced because the
+ * {@code REPLACE_EXISTING} option is not specified, or the target
+ * file is a non-empty directory
+ * @throws AtomicMoveNotSupportedException
+ * The options array contains the {@code ATOMIC_MOVE} option but
+ * the file cannot be moved as an atomic file system operation.
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkWrite(String) checkWrite}
+ * method is invoked to check write access to both the source and
+ * target file.
+ */
+ public abstract Path moveTo(Path target, CopyOption... options)
+ throws IOException;
+
+ /**
+ * Opens the directory referenced by this object, returning a {@code
+ * DirectoryStream} to iterate over all entries in the directory. The
+ * elements returned by the directory stream's {@link DirectoryStream#iterator
+ * iterator} are of type {@code Path}, each one representing an entry in the
+ * directory. The {@code Path} objects are obtained as if by {@link
+ * #resolve(Path) resolving} the name of the directory entry against this
+ * path.
+ *
+ * <p> The directory stream's {@code close} method should be invoked after
+ * iteration is completed so as to free any resources held for the open
+ * directory. The {@link Files#withDirectory Files.withDirectory} utility
+ * method is useful for cases where a task is performed on each accepted
+ * entry in a directory. This method closes the directory when iteration is
+ * complete (or an error occurs).
+ *
+ * <p> When an implementation supports operations on entries in the
+ * directory that execute in a race-free manner then the returned directory
+ * stream is a {@link SecureDirectoryStream}.
+ *
+ * @return A new and open {@code DirectoryStream} object
+ *
+ * @throws NotDirectoryException
+ * If the file could not otherwise be opened because it is not
+ * a directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the directory.
+ */
+ public abstract DirectoryStream<Path> newDirectoryStream()
+ throws IOException;
+
+ /**
+ * Opens the directory referenced by this object, returning a {@code
+ * DirectoryStream} to iterate over the entries in the directory. The
+ * elements returned by the directory stream's {@link DirectoryStream#iterator
+ * iterator} are of type {@code Path}, each one representing an entry in the
+ * directory. The {@code Path} objects are obtained as if by {@link
+ * #resolve(Path) resolving} the name of the directory entry against this
+ * path. The entries returned by the iterator are filtered by matching the
+ * {@code String} representation of their file names against the given
+ * <em>globbing</em> pattern.
+ *
+ * <p> For example, suppose we want to iterate over the files ending with
+ * ".java" in a directory:
+ * <pre>
+ * Path dir = ...
+ * DirectoryStream<Path> stream = dir.newDirectoryStream("*.java");
+ * </pre>
+ *
+ * <p> The globbing pattern is specified by the {@link
+ * FileSystem#getPathMatcher getPathMatcher} method.
+ *
+ * <p> The directory stream's {@code close} method should be invoked after
+ * iteration is completed so as to free any resources held for the open
+ * directory.
+ *
+ * <p> When an implementation supports operations on entries in the
+ * directory that execute in a race-free manner then the returned directory
+ * stream is a {@link SecureDirectoryStream}.
+ *
+ * @param glob
+ * The glob pattern
+ *
+ * @return A new and open {@code DirectoryStream} object
+ *
+ * @throws java.util.regex.PatternSyntaxException
+ * If the pattern is invalid
+ * @throws UnsupportedOperationException
+ * If the pattern syntax is not known to the implementation
+ * @throws NotDirectoryException
+ * If the file could not otherwise be opened because it is not
+ * a directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the directory.
+ */
+ public abstract DirectoryStream<Path> newDirectoryStream(String glob)
+ throws IOException;
+
+ /**
+ * Opens the directory referenced by this object, returning a {@code
+ * DirectoryStream} to iterate over the entries in the directory. The
+ * elements returned by the directory stream's {@link DirectoryStream#iterator
+ * iterator} are of type {@code Path}, each one representing an entry in the
+ * directory. The {@code Path} objects are obtained as if by {@link
+ * #resolve(Path) resolving} the name of the directory entry against this
+ * path. The entries returned by the iterator are filtered by the given
+ * {@link DirectoryStream.Filter filter}. The {@link DirectoryStreamFilters}
+ * class defines factory methods that create useful filters.
+ *
+ * <p> The directory stream's {@code close} method should be invoked after
+ * iteration is completed so as to free any resources held for the open
+ * directory. The {@link Files#withDirectory Files.withDirectory} utility
+ * method is useful for cases where a task is performed on each accepted
+ * entry in a directory. This method closes the directory when iteration is
+ * complete (or an error occurs).
+ *
+ * <p> Where the filter terminates due to an uncaught error or runtime
+ * exception then it propogated to the caller of the iterator's {@link
+ * Iterator#hasNext() hasNext} or {@link Iterator#next() next} methods.
+ *
+ * <p> When an implementation supports operations on entries in the
+ * directory that execute in a race-free manner then the returned directory
+ * stream is a {@link SecureDirectoryStream}.
+ *
+ * <p> <b>Usage Example:</b>
+ * Suppose we want to iterate over the files in a directory that are
+ * larger than 8K.
+ * <pre>
+ * DirectoryStream.Filter<Path> filter = new DirectoryStream.Filter<Path>() {
+ * public boolean accept(Path file) {
+ * try {
+ * long size = Attributes.readBasicFileAttributes(file).size();
+ * return (size > 8192L);
+ * } catch (IOException e) {
+ * // failed to get size
+ * return false;
+ * }
+ * }
+ * };
+ * Path dir = ...
+ * DirectoryStream<Path> stream = dir.newDirectoryStream(filter);
+ * </pre>
+ * @param filter
+ * The directory stream filter
+ *
+ * @return A new and open {@code DirectoryStream} object
+ *
+ * @throws NotDirectoryException
+ * If the file could not otherwise be opened because it is not
+ * a directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the directory.
+ */
+ public abstract DirectoryStream<Path> newDirectoryStream(DirectoryStream.Filter<? super Path> filter)
+ throws IOException;
+
+ /**
+ * Creates a new and empty file, failing if the file already exists.
+ *
+ * <p> This {@code Path} locates the file to create. The check for the
+ * existence of the file and the creation of the new file if it does not
+ * exist are a single operation that is atomic with respect to all other
+ * filesystem activities that might affect the directory.
+ *
+ * <p> The {@code attrs} parameter is an optional array of {@link FileAttribute
+ * file-attributes} to set atomically when creating the file. Each attribute
+ * is identified by its {@link FileAttribute#name name}. If more than one
+ * attribute of the same name is included in the array then all but the last
+ * occurrence is ignored.
+ *
+ * @param attrs
+ * An optional list of file attributes to set atomically when
+ * creating the file
+ *
+ * @return This path
+ *
+ * @throws UnsupportedOperationException
+ * If the array contains an attribute that cannot be set atomically
+ * when creating the file
+ * @throws FileAlreadyExistsException
+ * If a file of that name already exists
+ * <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkWrite(String) checkWrite}
+ * method is invoked to check write access to the new file.
+ */
+ public abstract Path createFile(FileAttribute<?>... attrs) throws IOException;
+
+ /**
+ * Creates a new directory.
+ *
+ * <p> This {@code Path} locates the directory to create. The check for the
+ * existence of the file and the creation of the directory if it does not
+ * exist are a single operation that is atomic with respect to all other
+ * filesystem activities that might affect the directory.
+ *
+ * <p> The {@code attrs} parameter is an optional array of {@link FileAttribute
+ * file-attributes} to set atomically when creating the directory. Each
+ * file attribute is identified by its {@link FileAttribute#name name}. If
+ * more than one attribute of the same name is included in the array then all
+ * but the last occurrence is ignored.
+ *
+ * @param attrs
+ * An optional list of file attributes to set atomically when
+ * creating the directory
+ *
+ * @return This path
+ *
+ * @throws UnsupportedOperationException
+ * If the array contains an attribute that cannot be set atomically
+ * when creating the directory
+ * @throws FileAlreadyExistsException
+ * If a directory could not otherwise be created because a file of
+ * that name already exists <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkWrite(String) checkWrite}
+ * method is invoked to check write access to the new directory.
+ */
+ public abstract Path createDirectory(FileAttribute<?>... attrs)
+ throws IOException;
+
+ /**
+ * Opens or creates a file, returning a seekable byte channel to access the
+ * file.
+ *
+ * <p> The {@code options} parameter determines how the file is opened.
+ * The {@link StandardOpenOption#READ READ} and {@link StandardOpenOption#WRITE WRITE}
+ * options determine if the file should be opened for reading and/or writing.
+ * If neither option (or the {@link StandardOpenOption#APPEND APPEND}
+ * option) is contained in the array then the file is opened for reading.
+ * By default reading or writing commences at the beginning of the file.
+ *
+ * <p> In the addition to {@code READ} and {@code WRITE}, the following
+ * options may be present:
+ *
+ * <table border=1 cellpadding=5 summary="">
+ * <tr> <th>Option</th> <th>Description</th> </tr>
+ * <tr>
+ * <td> {@link StandardOpenOption#APPEND APPEND} </td>
+ * <td> If this option is present then the file is opened for writing and
+ * each invocation of the channel's {@code write} method first advances
+ * the position to the end of the file and then writes the requested
+ * data. Whether the advancement of the position and the writing of the
+ * data are done in a single atomic operation is system-dependent and
+ * therefore unspecified. This option may not be used in conjunction
+ * with the {@code READ} or {@code TRUNCATE_EXISTING} options. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link StandardOpenOption#TRUNCATE_EXISTING TRUNCATE_EXISTING} </td>
+ * <td> If this option is present then the existing file is truncated to
+ * a size of 0 bytes. This option is ignored when the file is opened only
+ * for reading. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link StandardOpenOption#CREATE_NEW CREATE_NEW} </td>
+ * <td> If this option is present then a new file is created, failing if
+ * the file already exists or is a symbolic link. When creating a file the
+ * check for the existence of the file and the creation of the file if it
+ * does not exist is atomic with respect to other file system operations.
+ * This option is ignored when the file is opened only for reading. </td>
+ * </tr>
+ * <tr>
+ * <td > {@link StandardOpenOption#CREATE CREATE} </td>
+ * <td> If this option is present then an existing file is opened if it
+ * exists, otherwise a new file is created. This option is ignored if the
+ * {@code CREATE_NEW} option is also present or the file is opened only
+ * for reading. </td>
+ * </tr>
+ * <tr>
+ * <td > {@link StandardOpenOption#DELETE_ON_CLOSE DELETE_ON_CLOSE} </td>
+ * <td> When this option is present then the implementation makes a
+ * <em>best effort</em> attempt to delete the file when closed by the
+ * {@link SeekableByteChannel#close close} method. If the {@code close}
+ * method is not invoked then a <em>best effort</em> attempt is made to
+ * delete the file when the Java virtual machine terminates. </td>
+ * </tr>
+ * <tr>
+ * <td>{@link StandardOpenOption#SPARSE SPARSE} </td>
+ * <td> When creating a new file this option is a <em>hint</em> that the
+ * new file will be sparse. This option is ignored when not creating
+ * a new file. </td>
+ * </tr>
+ * <tr>
+ * <td> {@link StandardOpenOption#SYNC SYNC} </td>
+ * <td> Requires that every update to the file's content or metadata be
+ * written synchronously to the underlying storage device. (see <a
+ * href="package-summary.html#integrity"> Synchronized I/O file
+ * integrity</a>). </td>
+ * <tr>
+ * <tr>
+ * <td> {@link StandardOpenOption#DSYNC DSYNC} </td>
+ * <td> Requires that every update to the file's content be written
+ * synchronously to the underlying storage device. (see <a
+ * href="package-summary.html#integrity"> Synchronized I/O file
+ * integrity</a>). </td>
+ * </tr>
+ * </table>
+ *
+ * <p> An implementation may also support additional implementation specific
+ * options.
+ *
+ * <p> The {@code attrs} parameter is an optional array of file {@link
+ * FileAttribute file-attributes} to set atomically when a new file is created.
+ *
+ * <p> In the case of the default provider, the returned seekable byte channel
+ * is a {@link FileChannel}.
+ *
+ * <p> <b>Usage Examples:</b>
+ * <pre>
+ * Path file = ...
+ *
+ * // open file for reading
+ * ReadableByteChannel rbc = file.newByteChannel(EnumSet.of(READ)));
+ *
+ * // open file for writing to the end of an existing file, creating
+ * // the file if it doesn't already exist
+ * WritableByteChannel wbc = file.newByteChannel(EnumSet.of(CREATE,APPEND));
+ *
+ * // create file with initial permissions, opening it for both reading and writing
+ * FileAttribute<Set<PosixFilePermission>> perms = ...
+ * SeekableByteChannel sbc = file.newByteChannel(EnumSet.of(CREATE_NEW,READ,WRITE), perms);
+ * </pre>
+ *
+ * @param options
+ * Options specifying how the file is opened
+ * @param attrs
+ * An optional list of file attributes to set atomically when
+ * creating the file
+ *
+ * @return a new seekable byte channel
+ *
+ * @throws IllegalArgumentException
+ * If the set contains an invalid combination of options
+ * @throws UnsupportedOperationException
+ * If an unsupported open option is specified or the array contains
+ * attributes that cannot be set atomically when creating the file
+ * @throws FileAlreadyExistsException
+ * If a file of that name already exists and the {@link
+ * StandardOpenOption#CREATE_NEW CREATE_NEW} option is specified
+ * <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the path if the file is
+ * opened for reading. The {@link SecurityManager#checkWrite(String)
+ * checkWrite} method is invoked to check write access to the path
+ * if the file is opened for writing.
+ */
+ public abstract SeekableByteChannel newByteChannel(Set<? extends OpenOption> options,
+ FileAttribute<?>... attrs)
+ throws IOException;
+
+ /**
+ * Opens or creates a file, returning a seekable byte channel to access the
+ * file.
+ *
+ * <p> This method extends the options defined by the {@code FileRef}
+ * interface and to the options specified by the {@link
+ * #newByteChannel(Set,FileAttribute[]) newByteChannel} method
+ * except that the options are specified by an array. In the case of the
+ * default provider, the returned seekable byte channel is a {@link
+ * FileChannel}.
+ *
+ * @param options
+ * Options specifying how the file is opened
+ *
+ * @return a new seekable byte channel
+ *
+ * @throws IllegalArgumentException
+ * If the set contains an invalid combination of options
+ * @throws UnsupportedOperationException
+ * If an unsupported open option is specified
+ * @throws FileAlreadyExistsException
+ * If a file of that name already exists and the {@link
+ * StandardOpenOption#CREATE_NEW CREATE_NEW} option is specified
+ * <i>(optional specific exception)</i>
+ * @throws IOException {@inheritDoc}
+ * @throws SecurityException {@inheritDoc}
+ */
+ @Override
+ public abstract SeekableByteChannel newByteChannel(OpenOption... options)
+ throws IOException;
+
+ /**
+ * Opens the file located by this path for reading, returning an input
+ * stream to read bytes from the file. The stream will not be buffered, and
+ * is not required to support the {@link InputStream#mark mark} or {@link
+ * InputStream#reset reset} methods. The stream will be safe for access by
+ * multiple concurrent threads. Reading commences at the beginning of the file.
+ *
+ * @return An input stream to read bytes from the file
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the file.
+ */
+ public abstract InputStream newInputStream() throws IOException;
+
+ /**
+ * Opens or creates the file located by this path for writing, returning an
+ * output stream to write bytes to the file.
+ *
+ * <p> This method opens or creates a file in exactly the manner specified
+ * by the {@link Path#newByteChannel(Set,FileAttribute[]) newByteChannel}
+ * method except that the {@link StandardOpenOption#READ READ} option may not
+ * be present in the array of open options. If no open options are present
+ * then this method creates a new file for writing or truncates an existing
+ * file.
+ *
+ * <p> The resulting stream will not be buffered. The stream will be safe
+ * for access by multiple concurrent threads.
+ *
+ * <p> <b>Usage Example:</b>
+ * Suppose we wish to open a log file for writing so that we append to the
+ * file if it already exists, or create it when it doesn't exist.
+ * <pre>
+ * Path logfile = ...
+ * OutputStream out = new BufferedOutputStream(logfile.newOutputStream(CREATE, APPEND));
+ * </pre>
+ *
+ * @param options
+ * Options specifying how the file is opened
+ *
+ * @return a new seekable byte channel
+ *
+ * @throws IllegalArgumentException
+ * If {@code options} contains an invalid combination of options
+ * @throws UnsupportedOperationException
+ * If an unsupported open option is specified
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkWrite(String) checkWrite}
+ * method is invoked to check write access to the file.
+ */
+ public abstract OutputStream newOutputStream(OpenOption... options)
+ throws IOException;
+
+ /**
+ * Opens or creates the file located by this path for writing, returning an
+ * output stream to write bytes to the file.
+ *
+ * <p> This method opens or creates a file in exactly the manner specified
+ * by the {@link Path#newByteChannel(Set,FileAttribute[]) newByteChannel}
+ * method except that {@code options} parameter may not contain the {@link
+ * StandardOpenOption#READ READ} option. If no open options are present
+ * then this method creates a new file for writing or truncates an existing
+ * file.
+ *
+ * <p> The resulting stream will not be buffered. The stream will be safe
+ * for access by multiple concurrent threads.
+ *
+ * @param options
+ * Options specifying how the file is opened
+ * @param attrs
+ * An optional list of file attributes to set atomically when
+ * creating the file
+ *
+ * @return A new output stream
+ *
+ * @throws IllegalArgumentException
+ * If the set contains an invalid combination of options
+ * @throws UnsupportedOperationException
+ * If an unsupported open option is specified or the array contains
+ * attributes that cannot be set atomically when creating the file
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkWrite(String) checkWrite}
+ * method is invoked to check write access to the file.
+ */
+ public abstract OutputStream newOutputStream(Set<? extends OpenOption> options,
+ FileAttribute<?>... attrs)
+ throws IOException;
+
+ /**
+ * Tells whether or not the file located by this object is considered
+ * <em>hidden</em>. The exact definition of hidden is platform or provider
+ * dependent. On UNIX for example a file is considered to be hidden if its
+ * name begins with a period character ('.'). On Windows a file is
+ * considered hidden if it isn't a directory and the DOS {@link
+ * DosFileAttributes#isHidden hidden} attribute is set.
+ *
+ * <p> Depending on the implementation this method may require to access
+ * the file system to determine if the file is considered hidden.
+ *
+ * @return {@code true} if the file is considered hidden
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the file.
+ */
+ public abstract boolean isHidden() throws IOException;
+
+ /**
+ * Tests whether the file located by this path exists.
+ *
+ * <p> This convenience method is intended for cases where it is required to
+ * take action when it can be confirmed that a file exists. This method simply
+ * invokes the {@link #checkAccess checkAccess} method to check if the file
+ * exists. If the {@code checkAccess} method succeeds then this method returns
+ * {@code true}, otherwise if an {@code IOException} is thrown (because the
+ * file doesn't exist or cannot be accessed by this Java virtual machine)
+ * then {@code false} is returned.
+ *
+ * <p> Note that the result of this method is immediately outdated. If this
+ * method indicates the file exists then there is no guarantee that a
+ * subsequence access will succeed. Care should be taken when using this
+ * method in security sensitive applications.
+ *
+ * @return {@code true} if the file exists; {@code false} if the file does
+ * not exist or its existence cannot be determined.
+ *
+ * @throws SecurityException
+ * In the case of the default provider, the {@link
+ * SecurityManager#checkRead(String)} is invoked to check
+ * read access to the file.
+ *
+ * @see #notExists
+ */
+ public abstract boolean exists();
+
+ /**
+ * Tests whether the file located by this path does not exist.
+ *
+ * <p> This convenience method is intended for cases where it is required to
+ * take action when it can be confirmed that a file does not exist. This
+ * method invokes the {@link #checkAccess checkAccess} method to check if the
+ * file exists. If the file does not exist then {@code true} is returned,
+ * otherwise the file exists or cannot be accessed by this Java virtual
+ * machine and {@code false} is returned.
+ *
+ * <p> Note that this method is not the complement of the {@link #exists
+ * exists} method. Where it is not possible to determine if a file exists
+ * or not then both methods return {@code false}. As with the {@code exists}
+ * method, the result of this method is immediately outdated. If this
+ * method indicates the file does exist then there is no guarantee that a
+ * subsequence attempt to create the file will succeed. Care should be taken
+ * when using this method in security sensitive applications.
+ *
+ * @return {@code true} if the file does not exist; {@code false} if the
+ * file exists or its existence cannot be determined.
+ *
+ * @throws SecurityException
+ * In the case of the default provider, the {@link
+ * SecurityManager#checkRead(String)} is invoked to check
+ * read access to the file.
+ */
+ public abstract boolean notExists();
+
+ // -- watchable --
+
+ /**
+ * Registers the file located by this path with a watch service.
+ *
+ * <p> In this release, this path locates a directory that exists. The
+ * directory is registered with the watch service so that entries in the
+ * directory can be watched. The {@code events} parameter is an array of
+ * events to register and may contain the following events:
+ * <ul>
+ * <li>{@link StandardWatchEventKind#ENTRY_CREATE ENTRY_CREATE} -
+ * entry created or moved into the directory</li>
+ * <li>{@link StandardWatchEventKind#ENTRY_DELETE ENTRY_DELETE} -
+ * entry deleted or moved out of the directory</li>
+ * <li>{@link StandardWatchEventKind#ENTRY_MODIFY ENTRY_MODIFY} -
+ * entry in directory was modified</li>
+ * </ul>
+ *
+ * <p> The {@link WatchEvent#context context} for these events is the
+ * relative path between the directory located by this path, and the path
+ * that locates the directory entry that is created, deleted, or modified.
+ *
+ * <p> The set of events may include additional implementation specific
+ * event that are not defined by the enum {@link StandardWatchEventKind}
+ *
+ * <p> The {@code modifiers} parameter is an array of <em>modifiers</em>
+ * that qualify how the directory is registered. This release does not
+ * define any <em>standard</em> modifiers. The array may contain
+ * implementation specific modifiers.
+ *
+ * <p> Where a file is registered with a watch service by means of a symbolic
+ * link then it is implementation specific if the watch continues to depend
+ * on the existence of the link after it is registered.
+ *
+ * @param watcher
+ * The watch service to which this object is to be registered
+ * @param events
+ * The events for which this object should be registered
+ * @param modifiers
+ * The modifiers, if any, that modify how the object is registered
+ *
+ * @return A key representing the registration of this object with the
+ * given watch service
+ *
+ * @throws UnsupportedOperationException
+ * If unsupported events or modifiers are specified
+ * @throws IllegalArgumentException
+ * If an invalid combination of events or modifiers is specified
+ * @throws ClosedWatchServiceException
+ * If the watch service is closed
+ * @throws NotDirectoryException
+ * If the file is registered to watch the entries in a directory
+ * and the file is not a directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the file.
+ */
+ @Override
+ public abstract WatchKey register(WatchService watcher,
+ WatchEvent.Kind<?>[] events,
+ WatchEvent.Modifier... modifiers)
+ throws IOException;
+
+ /**
+ * Registers the file located by this path with a watch service.
+ *
+ * <p> An invocation of this method behaves in exactly the same way as the
+ * invocation
+ * <pre>
+ * watchable.{@link #register(WatchService,WatchEvent.Kind[],WatchEvent.Modifier[]) register}(watcher, events, new WatchEvent.Modifier[0]);
+ * </pre>
+ *
+ * <p> <b>Usage Example:</b>
+ * Suppose we wish to register a directory for entry create, delete, and modify
+ * events:
+ * <pre>
+ * Path dir = ...
+ * WatchService watcher = ...
+ *
+ * WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
+ * </pre>
+ * @param watcher
+ * The watch service to which this object is to be registered
+ * @param events
+ * The events for which this object should be registered
+ *
+ * @return A key representing the registration of this object with the
+ * given watch service
+ *
+ * @throws UnsupportedOperationException
+ * If unsupported events are specified
+ * @throws IllegalArgumentException
+ * If an invalid combination of events is specified
+ * @throws ClosedWatchServiceException
+ * If the watch service is closed
+ * @throws NotDirectoryException
+ * If the file is registered to watch the entries in a directory
+ * and the file is not a directory <i>(optional specific exception)</i>
+ * @throws IOException
+ * If an I/O error occurs
+ * @throws SecurityException
+ * In the case of the default provider, and a security manager is
+ * installed, the {@link SecurityManager#checkRead(String) checkRead}
+ * method is invoked to check read access to the file.
+ */
+ @Override
+ public abstract WatchKey register(WatchService watcher,
+ WatchEvent.Kind<?>... events)
+ throws IOException;
+
+ // -- Iterable --
+
+ /**
+ * Returns an iterator over the name elements of this path.
+ *
+ * <p> The first element returned by the iterator represents the name
+ * element that is closest to the root in the directory hierarchy, the
+ * second element is the next closest, and so on. The last element returned
+ * is the name of the file or directory denoted by this path. The {@link
+ * #getRoot root} component, if present, is not returned by the iterator.
+ *
+ * @return An iterator over the name elements of this path.
+ */
+ @Override
+ public abstract Iterator<Path> iterator();
+
+ // -- compareTo/equals/hashCode --
+
+ /**
+ * Compares two abstract paths lexicographically. The ordering defined by
+ * this method is provider specific, and in the case of the default
+ * provider, platform specific. This method does not access the file system
+ * and neither file is required to exist.
+ *
+ * @param other The path compared to this path.
+ *
+ * @return Zero if the argument is {@link #equals equal} to this path, a
+ * value less than zero if this path is lexicographically less than
+ * the argument, or a value greater than zero if this path is
+ * lexicographically greater than the argument
+ */
+ @Override
+ public abstract int compareTo(Path other);
+
+ /**
+ * Tests this path for equality with the given object.
+ *
+ * <p> If the given object is not a Path, or is a Path associated with a
+ * different provider, then this method immediately returns {@code false}.
+ *
+ * <p> Whether or not two path are equal depends on the file system
+ * implementation. In some cases the paths are compared without regard
+ * to case, and others are case sensitive. This method does not access the
+ * file system and the file is not required to exist.
+ *
+ * <p> This method satisfies the general contract of the {@link
+ * java.lang.Object#equals(Object) Object.equals} method. </p>
+ *
+ * @param ob
+ * The object to which this object is to be compared
+ *
+ * @return {@code true} if, and only if, the given object is a {@code Path}
+ * that is identical to this {@code Path}
+ */
+ @Override
+ public abstract boolean equals(Object ob);
+
+ /**
+ * Computes a hash code for this path.
+ *
+ * <p> The hash code is based upon the components of the path, and
+ * satisfies the general contract of the {@link Object#hashCode
+ * Object.hashCode} method.
+ *
+ * @return The hash-code value for this Path
+ */
+ @Override
+ public abstract int hashCode();
+
+ /**
+ * Returns the string representation of this path.
+ *
+ * <p> If this path was created by converting a path string using the
+ * {@link FileSystem#getPath getPath} method then the path string returned
+ * by this method may differ from the original String used to create the path.
+ *
+ * <p> The returned path string uses the default name {@link
+ * FileSystem#getSeparator separator} to separate names in the path.
+ *
+ * @return The string representation of this path
+ */
+ @Override
+ public abstract String toString();
+}