916 lines
41 KiB
Java
916 lines
41 KiB
Java
/*
|
|
* Copyright (c) 2007, 2013, Oracle and/or its affiliates. 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. 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.
|
|
*/
|
|
|
|
package java.nio.file;
|
|
|
|
import java.io.File;
|
|
import java.io.IOException;
|
|
import java.net.URI;
|
|
import java.nio.file.spi.FileSystemProvider;
|
|
import java.util.Iterator;
|
|
import java.util.NoSuchElementException;
|
|
|
|
/**
|
|
* An object that may be used to locate a file in a file system. It will
|
|
* typically represent a system dependent file path.
|
|
*
|
|
* <p> A {@code Path} represents a path that is hierarchical and composed of a
|
|
* sequence of directory and file name elements separated by a special separator
|
|
* or delimiter. A <em>root component</em>, that identifies a file system
|
|
* hierarchy, may also be present. The name element that is <em>farthest</em>
|
|
* from the root of the directory hierarchy is the name of a file or directory.
|
|
* The other name elements are directory names. A {@code Path} can represent a
|
|
* root, a root and a sequence of names, or simply one or more name elements.
|
|
* A {@code Path} is considered to be an <i>empty path</i> if it consists
|
|
* solely of one name element that is empty. Accessing a file using an
|
|
* <i>empty path</i> is equivalent to accessing the default directory of the
|
|
* file system. {@code Path} defines the {@link #getFileName() getFileName},
|
|
* {@link #getParent getParent}, {@link #getRoot getRoot}, and {@link #subpath
|
|
* subpath} methods to access the path components or a subsequence of its name
|
|
* elements.
|
|
*
|
|
* <p> In addition to accessing the components of a path, a {@code Path} also
|
|
* defines the {@link #resolve(Path) resolve} and {@link #resolveSibling(Path)
|
|
* resolveSibling} methods to combine paths. The {@link #relativize relativize}
|
|
* method that can be used to construct a relative path between two paths.
|
|
* Paths can be {@link #compareTo compared}, and tested against each other using
|
|
* the {@link #startsWith startsWith} and {@link #endsWith endsWith} methods.
|
|
*
|
|
* <p> This interface extends {@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. </p>
|
|
*
|
|
* <p> <b>WARNING:</b> This interface is only intended to be implemented by
|
|
* those developing custom file system implementations. Methods may be added to
|
|
* this interface in future releases. </p>
|
|
*
|
|
* <h2>Accessing Files</h2>
|
|
* <p> Paths may be used with the {@link Files} class to operate on files,
|
|
* directories, and other types of files. For example, suppose we want a {@link
|
|
* java.io.BufferedReader} to read text from a file "{@code access.log}". The
|
|
* file is located in a directory "{@code logs}" relative to the current working
|
|
* directory and is UTF-8 encoded.
|
|
* <pre>
|
|
* Path path = FileSystems.getDefault().getPath("logs", "access.log");
|
|
* BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8);
|
|
* </pre>
|
|
*
|
|
* <a id="interop"></a><h2>Interoperability</h2>
|
|
* <p> Paths 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 toPath}
|
|
* method may be used to obtain a {@code Path} from the abstract path name
|
|
* represented by a {@code java.io.File} object. The resulting {@code Path} can
|
|
* be used to operate on the same file as the {@code java.io.File} object. In
|
|
* addition, the {@link #toFile toFile} method is useful to construct a {@code
|
|
* File} from the {@code String} representation of a {@code Path}.
|
|
*
|
|
* <h2>Concurrency</h2>
|
|
* <p> Implementations of this interface are immutable and safe for use by
|
|
* multiple concurrent threads.
|
|
*
|
|
* @since 1.7
|
|
*/
|
|
|
|
public interface Path
|
|
extends Comparable<Path>, Iterable<Path>, Watchable
|
|
{
|
|
/**
|
|
* Returns a {@code Path} by converting a path string, or a sequence of
|
|
* strings that when joined form a path string. If {@code more} does not
|
|
* specify any elements then the value of the {@code first} parameter is
|
|
* the path string to convert. If {@code more} specifies one or more
|
|
* elements then each non-empty string, including {@code first}, is
|
|
* considered to be a sequence of name elements and is joined to form a
|
|
* path string. The details as to how the Strings are joined is provider
|
|
* specific but typically they will be joined using the
|
|
* {@link FileSystem#getSeparator name-separator} as the separator.
|
|
* For example, if the name separator is "{@code /}" and
|
|
* {@code getPath("/foo","bar","gus")} is invoked, then the path string
|
|
* {@code "/foo/bar/gus"} is converted to a {@code Path}. A {@code Path}
|
|
* representing an empty path is returned if {@code first} is the empty
|
|
* string and {@code more} does not contain any non-empty strings.
|
|
*
|
|
* <p> The {@code Path} is obtained by invoking the {@link FileSystem#getPath
|
|
* getPath} method of the {@link FileSystems#getDefault default} {@link
|
|
* FileSystem}.
|
|
*
|
|
* <p> Note that while this method is very convenient, using it will imply
|
|
* an assumed reference to the default {@code FileSystem} and limit the
|
|
* utility of the calling code. Hence it should not be used in library code
|
|
* intended for flexible reuse. A more flexible alternative is to use an
|
|
* existing {@code Path} instance as an anchor, such as:
|
|
* <pre>{@code
|
|
* Path dir = ...
|
|
* Path path = dir.resolve("file");
|
|
* }</pre>
|
|
*
|
|
* @param first
|
|
* the path string or initial part of the path string
|
|
* @param more
|
|
* additional strings to be joined to form the path string
|
|
*
|
|
* @return the resulting {@code Path}
|
|
*
|
|
* @throws InvalidPathException
|
|
* if the path string cannot be converted to a {@code Path}
|
|
*
|
|
* @see FileSystem#getPath
|
|
*
|
|
* @since 11
|
|
*/
|
|
public static Path of(String first, String... more) {
|
|
return FileSystems.getDefault().getPath(first, more);
|
|
}
|
|
|
|
/**
|
|
* Returns a {@code Path} by converting a URI.
|
|
*
|
|
* <p> This method iterates over the {@link FileSystemProvider#installedProviders()
|
|
* installed} providers to locate the provider that is identified by the
|
|
* URI {@link URI#getScheme scheme} of the given URI. URI schemes are
|
|
* compared without regard to case. If the provider is found then its {@link
|
|
* FileSystemProvider#getPath getPath} method is invoked to convert the
|
|
* URI.
|
|
*
|
|
* <p> In the case of the default provider, identified by the URI scheme
|
|
* "file", the given URI has a non-empty path component, and undefined query
|
|
* and fragment components. Whether the authority component may be present
|
|
* is platform specific. The returned {@code Path} is associated with the
|
|
* {@link FileSystems#getDefault default} file system.
|
|
*
|
|
* <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>{@code
|
|
* Path.of(}<i>p</i>{@code .}{@link Path#toUri() toUri}{@code ()).equals(}
|
|
* <i>p</i>{@code .}{@link Path#toAbsolutePath() toAbsolutePath}{@code ())}
|
|
* </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.
|
|
*
|
|
* @param uri
|
|
* the URI to convert
|
|
*
|
|
* @return the resulting {@code Path}
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if preconditions on the {@code uri} parameter do not hold. The
|
|
* format of the URI is provider specific.
|
|
* @throws FileSystemNotFoundException
|
|
* The file system, identified by the URI, does not exist and
|
|
* cannot be created automatically, or the provider identified by
|
|
* the URI's scheme component is not installed
|
|
* @throws SecurityException
|
|
* if a security manager is installed and it denies an unspecified
|
|
* permission to access the file system
|
|
*
|
|
* @since 11
|
|
*/
|
|
public static Path of(URI uri) {
|
|
String scheme = uri.getScheme();
|
|
if (scheme == null)
|
|
throw new IllegalArgumentException("Missing scheme");
|
|
|
|
// check for default provider to avoid loading of installed providers
|
|
if (scheme.equalsIgnoreCase("file"))
|
|
return FileSystems.getDefault().provider().getPath(uri);
|
|
|
|
// try to find provider
|
|
for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
|
|
if (provider.getScheme().equalsIgnoreCase(scheme)) {
|
|
return provider.getPath(uri);
|
|
}
|
|
}
|
|
|
|
throw new FileSystemNotFoundException("Provider \"" + scheme + "\" not installed");
|
|
}
|
|
|
|
/**
|
|
* Returns the file system that created this object.
|
|
*
|
|
* @return the file system that created this object
|
|
*/
|
|
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
|
|
*/
|
|
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}
|
|
*/
|
|
Path getRoot();
|
|
|
|
/**
|
|
* Returns the name of the file or directory denoted by this path as a
|
|
* {@code Path} object. 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
|
|
*/
|
|
Path getFileName();
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
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
|
|
*/
|
|
int getNameCount();
|
|
|
|
/**
|
|
* Returns a name element of this path as a {@code Path} object.
|
|
*
|
|
* <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
|
|
*/
|
|
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.
|
|
*/
|
|
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.
|
|
*
|
|
* <p> If the given path is associated with a different {@code FileSystem}
|
|
* to this path then {@code false} is returned.
|
|
*
|
|
* @param other
|
|
* the given path
|
|
*
|
|
* @return {@code true} if this path starts with the given path; otherwise
|
|
* {@code false}
|
|
*/
|
|
boolean startsWith(Path other);
|
|
|
|
/**
|
|
* Tests if this path starts with a {@code Path}, constructed by converting
|
|
* the given path string, in exactly the manner specified by the {@link
|
|
* #startsWith(Path) startsWith(Path)} method. On UNIX for example, the path
|
|
* "{@code foo/bar}" starts with "{@code foo}" and "{@code foo/bar}". It
|
|
* does not start with "{@code f}" or "{@code fo}".
|
|
*
|
|
* @param other
|
|
* the given path string
|
|
*
|
|
* @return {@code true} if this path starts with the given path; otherwise
|
|
* {@code false}
|
|
*
|
|
* @throws InvalidPathException
|
|
* If the path string cannot be converted to a Path.
|
|
*/
|
|
boolean startsWith(String 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.
|
|
*
|
|
* <p> If the given path is associated with a different {@code FileSystem}
|
|
* to this path then {@code false} is returned.
|
|
*
|
|
* @param other
|
|
* the given path
|
|
*
|
|
* @return {@code true} if this path ends with the given path; otherwise
|
|
* {@code false}
|
|
*/
|
|
boolean endsWith(Path other);
|
|
|
|
/**
|
|
* Tests if this path ends with a {@code Path}, constructed by converting
|
|
* the given path string, in exactly the manner specified by the {@link
|
|
* #endsWith(Path) endsWith(Path)} method. On UNIX for example, the path
|
|
* "{@code foo/bar}" ends with "{@code foo/bar}" and "{@code bar}". It does
|
|
* not end with "{@code r}" or "{@code /bar}". Note that trailing separators
|
|
* are not taken into account, and so invoking this method on the {@code
|
|
* Path}"{@code foo/bar}" with the {@code String} "{@code bar/}" returns
|
|
* {@code true}.
|
|
*
|
|
* @param other
|
|
* the given path string
|
|
*
|
|
* @return {@code true} if this path ends with the given path; otherwise
|
|
* {@code false}
|
|
*
|
|
* @throws InvalidPathException
|
|
* If the path string cannot be converted to a Path.
|
|
*/
|
|
boolean endsWith(String 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 it is 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; an empty path is returned if this path
|
|
* does have a root component and all name elements are redundant
|
|
*
|
|
* @see #getParent
|
|
* @see #toRealPath
|
|
*/
|
|
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 an <i>empty path</i> then this method trivially returns this path.
|
|
* 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
|
|
*
|
|
* @return the resulting path
|
|
*
|
|
* @see #relativize
|
|
*/
|
|
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. For example, suppose that the name
|
|
* separator is "{@code /}" and a path represents "{@code foo/bar}", then
|
|
* invoking this method with the path string "{@code gus}" will result in
|
|
* the {@code Path} "{@code foo/bar/gus}".
|
|
*
|
|
* @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
|
|
*/
|
|
Path resolve(String other);
|
|
|
|
/**
|
|
* Resolves the given path against this path's {@link #getParent parent}
|
|
* path. This is useful where a file name needs to be <i>replaced</i> with
|
|
* another file name. For example, suppose that the name separator is
|
|
* "{@code /}" and a path represents "{@code dir1/dir2/foo}", then invoking
|
|
* this method with the {@code Path} "{@code bar}" will result in the {@code
|
|
* Path} "{@code dir1/dir2/bar}". If this path does not have a parent path,
|
|
* or {@code other} is {@link #isAbsolute() absolute}, then this method
|
|
* returns {@code other}. If {@code other} is an empty path then this method
|
|
* returns this path's parent, or where this path doesn't have a parent, the
|
|
* empty path.
|
|
*
|
|
* @param other
|
|
* the path to resolve against this path's parent
|
|
*
|
|
* @return the resulting path
|
|
*
|
|
* @see #resolve(Path)
|
|
*/
|
|
Path resolveSibling(Path other);
|
|
|
|
/**
|
|
* Converts a given path string to a {@code Path} and resolves it against
|
|
* this path's {@link #getParent parent} path in exactly the manner
|
|
* specified by the {@link #resolveSibling(Path) resolveSibling} method.
|
|
*
|
|
* @param other
|
|
* the path string to resolve against this path's parent
|
|
*
|
|
* @return the resulting path
|
|
*
|
|
* @throws InvalidPathException
|
|
* if the path string cannot be converted to a Path.
|
|
*
|
|
* @see FileSystem#getPath
|
|
*/
|
|
Path resolveSibling(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 an <i>empty path</i> is returned.
|
|
*
|
|
* <p> For any two {@link #normalize normalized} 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 Files#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 path to relativize against this path
|
|
*
|
|
* @return the resulting relative path, or an empty path if both paths are
|
|
* equal
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if {@code other} is not a {@code Path} that can be relativized
|
|
* against this path
|
|
*/
|
|
Path relativize(Path other);
|
|
|
|
/**
|
|
* Returns a URI to represent this path.
|
|
*
|
|
* <p> This method constructs an absolute {@link URI} with a {@link
|
|
* URI#getScheme() scheme} equal to the URI scheme that identifies the
|
|
* provider. The exact form of the scheme specific part is highly provider
|
|
* dependent.
|
|
*
|
|
* <p> In the case of the default provider, the URI is hierarchical with
|
|
* a {@link URI#getPath() path} component that is absolute. The query and
|
|
* 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 the URI representing this path
|
|
*
|
|
* @throws java.io.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, and the URI of the enclosing file system cannot be
|
|
* obtained
|
|
*
|
|
* @throws SecurityException
|
|
* In the case of the default provider, and a security manager
|
|
* is installed, the {@link #toAbsolutePath toAbsolutePath} method
|
|
* throws a security exception.
|
|
*/
|
|
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 java.io.IOError
|
|
* if an I/O error occurs
|
|
* @throws SecurityException
|
|
* In the case of the default provider, a security manager
|
|
* is installed, and this path is not absolute, then the security
|
|
* manager's {@link SecurityManager#checkPropertyAccess(String)
|
|
* checkPropertyAccess} method is invoked to check access to the
|
|
* system property {@code user.dir}
|
|
*/
|
|
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 Files#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 options} array may be used to indicate how symbolic links
|
|
* are handled. By default, symbolic links are resolved to their final
|
|
* target. If the option {@link LinkOption#NOFOLLOW_LINKS NOFOLLOW_LINKS} is
|
|
* present 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 cause 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.
|
|
*
|
|
* @param options
|
|
* options indicating how symbolic links are handled
|
|
*
|
|
* @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 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}
|
|
*/
|
|
Path toRealPath(LinkOption... options) throws IOException;
|
|
|
|
/**
|
|
* Returns a {@link File} object representing this path. Where this {@code
|
|
* Path} is associated with the default provider, then this method is
|
|
* equivalent to returning a {@code File} object constructed with the
|
|
* {@code String} representation of this path.
|
|
*
|
|
* <p> If this path was created by invoking the {@code File} {@link
|
|
* File#toPath toPath} method then there is no guarantee that the {@code
|
|
* File} object returned by this method is {@link #equals equal} to the
|
|
* original {@code File}.
|
|
*
|
|
* @return a {@code File} object representing this path
|
|
*
|
|
* @throws UnsupportedOperationException
|
|
* if this {@code Path} is not associated with the default provider
|
|
*/
|
|
File toFile();
|
|
|
|
// -- 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 the events to
|
|
* register and may contain the following events:
|
|
* <ul>
|
|
* <li>{@link StandardWatchEventKinds#ENTRY_CREATE ENTRY_CREATE} -
|
|
* entry created or moved into the directory</li>
|
|
* <li>{@link StandardWatchEventKinds#ENTRY_DELETE ENTRY_DELETE} -
|
|
* entry deleted or moved out of the directory</li>
|
|
* <li>{@link StandardWatchEventKinds#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 StandardWatchEventKinds}
|
|
*
|
|
* <p> The {@code modifiers} parameter specifies <em>modifiers</em> that
|
|
* qualify how the directory is registered. This release does not define any
|
|
* <em>standard</em> modifiers. It 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 symbolic 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
|
|
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
|
|
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
|
|
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.
|
|
*
|
|
* <p> This method may not be used to compare paths that are associated
|
|
* with different file system providers.
|
|
*
|
|
* @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
|
|
*
|
|
* @throws ClassCastException
|
|
* if the paths are associated with different providers
|
|
*/
|
|
@Override
|
|
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 {@code FileSystem}, then this method 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. Where required, the
|
|
* {@link Files#isSameFile isSameFile} method may be used to check if two
|
|
* paths locate the same file.
|
|
*
|
|
* <p> This method satisfies the general contract of the {@link
|
|
* java.lang.Object#equals(Object) Object.equals} method. </p>
|
|
*
|
|
* @param other
|
|
* 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}
|
|
*/
|
|
boolean equals(Object other);
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
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
|
|
*/
|
|
String toString();
|
|
}
|