/* |
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* Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.nio.file; |
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import java.io.File; |
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import java.io.IOException; |
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import java.net.URI; |
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import java.util.Iterator; |
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/** |
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* An object that may be used to locate a file in a file system. It will |
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* typically represent a system dependent file path. |
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* |
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* <p> A {@code Path} represents a path that is hierarchical and composed of a |
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* sequence of directory and file name elements separated by a special separator |
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* or delimiter. A <em>root component</em>, that identifies a file system |
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* hierarchy, may also be present. The name element that is <em>farthest</em> |
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* from the root of the directory hierarchy is the name of a file or directory. |
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* The other name elements are directory names. A {@code Path} can represent a |
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* root, a root and a sequence of names, or simply one or more name elements. |
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* A {@code Path} is considered to be an <i>empty path</i> if it consists |
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* solely of one name element that is empty. Accessing a file using an |
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* <i>empty path</i> is equivalent to accessing the default directory of the |
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* file system. {@code Path} defines the {@link #getFileName() getFileName}, |
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* {@link #getParent getParent}, {@link #getRoot getRoot}, and {@link #subpath |
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* subpath} methods to access the path components or a subsequence of its name |
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* elements. |
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* |
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* <p> In addition to accessing the components of a path, a {@code Path} also |
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* defines the {@link #resolve(Path) resolve} and {@link #resolveSibling(Path) |
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* resolveSibling} methods to combine paths. The {@link #relativize relativize} |
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* method that can be used to construct a relative path between two paths. |
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* Paths can be {@link #compareTo compared}, and tested against each other using |
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* the {@link #startsWith startsWith} and {@link #endsWith endsWith} methods. |
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* |
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* <p> This interface extends {@link Watchable} interface so that a directory |
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* located by a path can be {@link #register registered} with a {@link |
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* WatchService} and entries in the directory watched. </p> |
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* |
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* <p> <b>WARNING:</b> This interface is only intended to be implemented by |
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* those developing custom file system implementations. Methods may be added to |
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* this interface in future releases. </p> |
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* |
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* <h2>Accessing Files</h2> |
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* <p> Paths may be used with the {@link Files} class to operate on files, |
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* directories, and other types of files. For example, suppose we want a {@link |
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* java.io.BufferedReader} to read text from a file "{@code access.log}". The |
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* file is located in a directory "{@code logs}" relative to the current working |
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* directory and is UTF-8 encoded. |
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* <pre> |
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* Path path = FileSystems.getDefault().getPath("logs", "access.log"); |
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* BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8); |
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* </pre> |
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* |
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* <a name="interop"></a><h2>Interoperability</h2> |
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* <p> Paths associated with the default {@link |
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* java.nio.file.spi.FileSystemProvider provider} are generally interoperable |
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* with the {@link java.io.File java.io.File} class. Paths created by other |
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* providers are unlikely to be interoperable with the abstract path names |
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* represented by {@code java.io.File}. The {@link java.io.File#toPath toPath} |
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* method may be used to obtain a {@code Path} from the abstract path name |
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* represented by a {@code java.io.File} object. The resulting {@code Path} can |
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* be used to operate on the same file as the {@code java.io.File} object. In |
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* addition, the {@link #toFile toFile} method is useful to construct a {@code |
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* File} from the {@code String} representation of a {@code Path}. |
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* |
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* <h2>Concurrency</h2> |
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* <p> Implementations of this interface are immutable and safe for use by |
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* multiple concurrent threads. |
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* |
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* @since 1.7 |
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* @see Paths |
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*/ |
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public interface Path |
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extends Comparable<Path>, Iterable<Path>, Watchable |
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{ |
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/** |
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* Returns the file system that created this object. |
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* |
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* @return the file system that created this object |
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*/ |
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FileSystem getFileSystem(); |
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/** |
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* Tells whether or not this path is absolute. |
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* |
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* <p> An absolute path is complete in that it doesn't need to be combined |
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* with other path information in order to locate a file. |
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* |
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* @return {@code true} if, and only if, this path is absolute |
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*/ |
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boolean isAbsolute(); |
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/** |
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* Returns the root component of this path as a {@code Path} object, |
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* or {@code null} if this path does not have a root component. |
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* |
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* @return a path representing the root component of this path, |
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* or {@code null} |
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*/ |
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Path getRoot(); |
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/** |
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* Returns the name of the file or directory denoted by this path as a |
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* {@code Path} object. The file name is the <em>farthest</em> element from |
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* the root in the directory hierarchy. |
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* |
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* @return a path representing the name of the file or directory, or |
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* {@code null} if this path has zero elements |
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*/ |
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Path getFileName(); |
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/** |
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* Returns the <em>parent path</em>, or {@code null} if this path does not |
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* have a parent. |
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* |
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* <p> The parent of this path object consists of this path's root |
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* component, if any, and each element in the path except for the |
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* <em>farthest</em> from the root in the directory hierarchy. This method |
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* does not access the file system; the path or its parent may not exist. |
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* Furthermore, this method does not eliminate special names such as "." |
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* and ".." that may be used in some implementations. On UNIX for example, |
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* the parent of "{@code /a/b/c}" is "{@code /a/b}", and the parent of |
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* {@code "x/y/.}" is "{@code x/y}". This method may be used with the {@link |
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* #normalize normalize} method, to eliminate redundant names, for cases where |
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* <em>shell-like</em> navigation is required. |
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* |
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* <p> If this path has one or more elements, and no root component, then |
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* this method is equivalent to evaluating the expression: |
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* <blockquote><pre> |
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* subpath(0, getNameCount()-1); |
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* </pre></blockquote> |
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* |
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* @return a path representing the path's parent |
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*/ |
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Path getParent(); |
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/** |
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* Returns the number of name elements in the path. |
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* |
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* @return the number of elements in the path, or {@code 0} if this path |
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* only represents a root component |
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*/ |
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int getNameCount(); |
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/** |
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* Returns a name element of this path as a {@code Path} object. |
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* |
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* <p> The {@code index} parameter is the index of the name element to return. |
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* The element that is <em>closest</em> to the root in the directory hierarchy |
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* has index {@code 0}. The element that is <em>farthest</em> from the root |
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* has index {@link #getNameCount count}{@code -1}. |
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* |
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* @param index |
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* the index of the element |
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* |
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* @return the name element |
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* |
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* @throws IllegalArgumentException |
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* if {@code index} is negative, {@code index} is greater than or |
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* equal to the number of elements, or this path has zero name |
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* elements |
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*/ |
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Path getName(int index); |
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/** |
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* Returns a relative {@code Path} that is a subsequence of the name |
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* elements of this path. |
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* |
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* <p> The {@code beginIndex} and {@code endIndex} parameters specify the |
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* subsequence of name elements. The name that is <em>closest</em> to the root |
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* in the directory hierarchy has index {@code 0}. The name that is |
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* <em>farthest</em> from the root has index {@link #getNameCount |
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* count}{@code -1}. The returned {@code Path} object has the name elements |
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* that begin at {@code beginIndex} and extend to the element at index {@code |
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* endIndex-1}. |
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* |
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* @param beginIndex |
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* the index of the first element, inclusive |
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* @param endIndex |
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* the index of the last element, exclusive |
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* |
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* @return a new {@code Path} object that is a subsequence of the name |
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* elements in this {@code Path} |
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* |
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* @throws IllegalArgumentException |
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* if {@code beginIndex} is negative, or greater than or equal to |
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* the number of elements. If {@code endIndex} is less than or |
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* equal to {@code beginIndex}, or larger than the number of elements. |
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*/ |
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Path subpath(int beginIndex, int endIndex); |
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/** |
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* Tests if this path starts with the given path. |
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* |
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* <p> This path <em>starts</em> with the given path if this path's root |
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* component <em>starts</em> with the root component of the given path, |
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* and this path starts with the same name elements as the given path. |
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* If the given path has more name elements than this path then {@code false} |
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* is returned. |
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* |
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* <p> Whether or not the root component of this path starts with the root |
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* component of the given path is file system specific. If this path does |
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* not have a root component and the given path has a root component then |
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* this path does not start with the given path. |
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* |
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* <p> If the given path is associated with a different {@code FileSystem} |
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* to this path then {@code false} is returned. |
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* |
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* @param other |
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* the given path |
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* |
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* @return {@code true} if this path starts with the given path; otherwise |
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* {@code false} |
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*/ |
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boolean startsWith(Path other); |
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/** |
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* Tests if this path starts with a {@code Path}, constructed by converting |
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* the given path string, in exactly the manner specified by the {@link |
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* #startsWith(Path) startsWith(Path)} method. On UNIX for example, the path |
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* "{@code foo/bar}" starts with "{@code foo}" and "{@code foo/bar}". It |
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* does not start with "{@code f}" or "{@code fo}". |
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* |
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* @param other |
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* the given path string |
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* |
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* @return {@code true} if this path starts with the given path; otherwise |
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* {@code false} |
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* |
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* @throws InvalidPathException |
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* If the path string cannot be converted to a Path. |
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*/ |
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boolean startsWith(String other); |
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/** |
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* Tests if this path ends with the given path. |
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* |
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* <p> If the given path has <em>N</em> elements, and no root component, |
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* and this path has <em>N</em> or more elements, then this path ends with |
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* the given path if the last <em>N</em> elements of each path, starting at |
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* the element farthest from the root, are equal. |
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* |
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* <p> If the given path has a root component then this path ends with the |
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* given path if the root component of this path <em>ends with</em> the root |
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* component of the given path, and the corresponding elements of both paths |
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* are equal. Whether or not the root component of this path ends with the |
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* root component of the given path is file system specific. If this path |
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* does not have a root component and the given path has a root component |
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* then this path does not end with the given path. |
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* |
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* <p> If the given path is associated with a different {@code FileSystem} |
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* to this path then {@code false} is returned. |
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* |
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* @param other |
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* the given path |
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* |
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* @return {@code true} if this path ends with the given path; otherwise |
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* {@code false} |
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*/ |
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boolean endsWith(Path other); |
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/** |
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* Tests if this path ends with a {@code Path}, constructed by converting |
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* the given path string, in exactly the manner specified by the {@link |
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* #endsWith(Path) endsWith(Path)} method. On UNIX for example, the path |
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* "{@code foo/bar}" ends with "{@code foo/bar}" and "{@code bar}". It does |
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* not end with "{@code r}" or "{@code /bar}". Note that trailing separators |
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* are not taken into account, and so invoking this method on the {@code |
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* Path}"{@code foo/bar}" with the {@code String} "{@code bar/}" returns |
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* {@code true}. |
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* |
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* @param other |
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* the given path string |
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* |
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* @return {@code true} if this path ends with the given path; otherwise |
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* {@code false} |
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* |
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* @throws InvalidPathException |
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* If the path string cannot be converted to a Path. |
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*/ |
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boolean endsWith(String other); |
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/** |
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* Returns a path that is this path with redundant name elements eliminated. |
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* |
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* <p> The precise definition of this method is implementation dependent but |
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* in general it derives from this path, a path that does not contain |
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* <em>redundant</em> name elements. In many file systems, the "{@code .}" |
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* and "{@code ..}" are special names used to indicate the current directory |
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* and parent directory. In such file systems all occurrences of "{@code .}" |
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* are considered redundant. If a "{@code ..}" is preceded by a |
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* non-"{@code ..}" name then both names are considered redundant (the |
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* process to identify such names is repeated until it is no longer |
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* applicable). |
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* |
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* <p> This method does not access the file system; the path may not locate |
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* a file that exists. Eliminating "{@code ..}" and a preceding name from a |
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* path may result in the path that locates a different file than the original |
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* path. This can arise when the preceding name is a symbolic link. |
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* |
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* @return the resulting path or this path if it does not contain |
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* redundant name elements; an empty path is returned if this path |
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* does have a root component and all name elements are redundant |
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* |
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* @see #getParent |
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* @see #toRealPath |
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*/ |
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Path normalize(); |
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// -- resolution and relativization -- |
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/** |
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* Resolve the given path against this path. |
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* |
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* <p> If the {@code other} parameter is an {@link #isAbsolute() absolute} |
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* path then this method trivially returns {@code other}. If {@code other} |
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* is an <i>empty path</i> then this method trivially returns this path. |
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* Otherwise this method considers this path to be a directory and resolves |
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* the given path against this path. In the simplest case, the given path |
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* does not have a {@link #getRoot root} component, in which case this method |
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* <em>joins</em> the given path to this path and returns a resulting path |
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* that {@link #endsWith ends} with the given path. Where the given path has |
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* a root component then resolution is highly implementation dependent and |
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* therefore unspecified. |
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* |
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* @param other |
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* the path to resolve against this path |
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* |
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* @return the resulting path |
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* |
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* @see #relativize |
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*/ |
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Path resolve(Path other); |
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/** |
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* Converts a given path string to a {@code Path} and resolves it against |
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* this {@code Path} in exactly the manner specified by the {@link |
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* #resolve(Path) resolve} method. For example, suppose that the name |
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* separator is "{@code /}" and a path represents "{@code foo/bar}", then |
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* invoking this method with the path string "{@code gus}" will result in |
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* the {@code Path} "{@code foo/bar/gus}". |
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* |
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* @param other |
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* the path string to resolve against this path |
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* |
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* @return the resulting path |
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* |
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* @throws InvalidPathException |
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* if the path string cannot be converted to a Path. |
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* |
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* @see FileSystem#getPath |
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*/ |
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Path resolve(String other); |
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/** |
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* Resolves the given path against this path's {@link #getParent parent} |
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* path. This is useful where a file name needs to be <i>replaced</i> with |
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* another file name. For example, suppose that the name separator is |
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* "{@code /}" and a path represents "{@code dir1/dir2/foo}", then invoking |
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* this method with the {@code Path} "{@code bar}" will result in the {@code |
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* Path} "{@code dir1/dir2/bar}". If this path does not have a parent path, |
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* or {@code other} is {@link #isAbsolute() absolute}, then this method |
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* returns {@code other}. If {@code other} is an empty path then this method |
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* returns this path's parent, or where this path doesn't have a parent, the |
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* empty path. |
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* |
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* @param other |
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* the path to resolve against this path's parent |
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* |
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* @return the resulting path |
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* |
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* @see #resolve(Path) |
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*/ |
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Path resolveSibling(Path other); |
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/** |
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* Converts a given path string to a {@code Path} and resolves it against |
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* this path's {@link #getParent parent} path in exactly the manner |
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* specified by the {@link #resolveSibling(Path) resolveSibling} method. |
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* |
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* @param other |
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* the path string to resolve against this path's parent |
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* |
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* @return the resulting path |
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* |
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* @throws InvalidPathException |
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* if the path string cannot be converted to a Path. |
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* |
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* @see FileSystem#getPath |
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*/ |
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Path resolveSibling(String other); |
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/** |
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* Constructs a relative path between this path and a given path. |
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* |
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* <p> Relativization is the inverse of {@link #resolve(Path) resolution}. |
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* This method attempts to construct a {@link #isAbsolute relative} path |
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* that when {@link #resolve(Path) resolved} against this path, yields a |
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* path that locates the same file as the given path. For example, on UNIX, |
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* if this path is {@code "/a/b"} and the given path is {@code "/a/b/c/d"} |
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* then the resulting relative path would be {@code "c/d"}. Where this |
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* path and the given path do not have a {@link #getRoot root} component, |
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* then a relative path can be constructed. A relative path cannot be |
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* constructed if only one of the paths have a root component. Where both |
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* paths have a root component then it is implementation dependent if a |
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* relative path can be constructed. If this path and the given path are |
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* {@link #equals equal} then an <i>empty path</i> is returned. |
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* |
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* <p> For any two {@link #normalize normalized} paths <i>p</i> and |
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* <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> |
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* </blockquote> |
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* |
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* <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 |
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* 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"}. |
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* |
|
* @param other |
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* the path to relativize against this path |
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* |
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* @return the resulting relative path, or an empty path if both paths are |
|
* equal |
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* |
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* @throws IllegalArgumentException |
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* if {@code other} is not a {@code Path} that can be relativized |
|
* against this path |
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*/ |
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Path relativize(Path other); |
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/** |
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* Returns a URI to represent this path. |
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* |
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* <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(); |
|
} |