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| 1 | /* | ||
| 2 | * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package java.nio.file; | ||
| 27 | |||
| 28 | import java.nio.file.spi.FileSystemProvider; | ||
| 29 | import java.net.URI; | ||
| 30 | |||
| 31 | /** | ||
| 32 | * This class consists exclusively of static methods that return a {@link Path} | ||
| 33 | * by converting a path string or {@link URI}. | ||
| 34 | * | ||
| 35 | * @since 1.7 | ||
| 36 | */ | ||
| 37 | |||
| 38 | public final class Paths { | ||
| 39 | private Paths() { } | ||
| 40 | |||
| 41 | /** | ||
| 42 | * Converts a path string, or a sequence of strings that when joined form | ||
| 43 | * a path string, to a {@code Path}. If {@code more} does not specify any | ||
| 44 | * elements then the value of the {@code first} parameter is the path string | ||
| 45 | * to convert. If {@code more} specifies one or more elements then each | ||
| 46 | * non-empty string, including {@code first}, is considered to be a sequence | ||
| 47 | * of name elements (see {@link Path}) and is joined to form a path string. | ||
| 48 | * The details as to how the Strings are joined is provider specific but | ||
| 49 | * typically they will be joined using the {@link FileSystem#getSeparator | ||
| 50 | * name-separator} as the separator. For example, if the name separator is | ||
| 51 | * "{@code /}" and {@code getPath("/foo","bar","gus")} is invoked, then the | ||
| 52 | * path string {@code "/foo/bar/gus"} is converted to a {@code Path}. | ||
| 53 | * A {@code Path} representing an empty path is returned if {@code first} | ||
| 54 | * is the empty string and {@code more} does not contain any non-empty | ||
| 55 | * strings. | ||
| 56 | * | ||
| 57 | * <p> The {@code Path} is obtained by invoking the {@link FileSystem#getPath | ||
| 58 | * getPath} method of the {@link FileSystems#getDefault default} {@link | ||
| 59 | * FileSystem}. | ||
| 60 | * | ||
| 61 | * <p> Note that while this method is very convenient, using it will imply | ||
| 62 | * an assumed reference to the default {@code FileSystem} and limit the | ||
| 63 | * utility of the calling code. Hence it should not be used in library code | ||
| 64 | * intended for flexible reuse. A more flexible alternative is to use an | ||
| 65 | * existing {@code Path} instance as an anchor, such as: | ||
| 66 | * <pre> | ||
| 67 | * Path dir = ... | ||
| 68 | * Path path = dir.resolve("file"); | ||
| 69 | * </pre> | ||
| 70 | * | ||
| 71 | * @param first | ||
| 72 | * the path string or initial part of the path string | ||
| 73 | * @param more | ||
| 74 | * additional strings to be joined to form the path string | ||
| 75 | * | ||
| 76 | * @return the resulting {@code Path} | ||
| 77 | * | ||
| 78 | * @throws InvalidPathException | ||
| 79 | * if the path string cannot be converted to a {@code Path} | ||
| 80 | * | ||
| 81 | * @see FileSystem#getPath | ||
| 82 | */ | ||
| 83 | public static Path get(String first, String... more) { | ||
| 84 | return FileSystems.getDefault().getPath(first, more); | ||
| 85 | } | ||
| 86 | |||
| 87 | /** | ||
| 88 | * Converts the given URI to a {@link Path} object. | ||
| 89 | * | ||
| 90 | * <p> This method iterates over the {@link FileSystemProvider#installedProviders() | ||
| 91 | * installed} providers to locate the provider that is identified by the | ||
| 92 | * URI {@link URI#getScheme scheme} of the given URI. URI schemes are | ||
| 93 | * compared without regard to case. If the provider is found then its {@link | ||
| 94 | * FileSystemProvider#getPath getPath} method is invoked to convert the | ||
| 95 | * URI. | ||
| 96 | * | ||
| 97 | * <p> In the case of the default provider, identified by the URI scheme | ||
| 98 | * "file", the given URI has a non-empty path component, and undefined query | ||
| 99 | * and fragment components. Whether the authority component may be present | ||
| 100 | * is platform specific. The returned {@code Path} is associated with the | ||
| 101 | * {@link FileSystems#getDefault default} file system. | ||
| 102 | * | ||
| 103 | * <p> The default provider provides a similar <em>round-trip</em> guarantee | ||
| 104 | * to the {@link java.io.File} class. For a given {@code Path} <i>p</i> it | ||
| 105 | * is guaranteed that | ||
| 106 | * <blockquote><tt> | ||
| 107 | * Paths.get(</tt><i>p</i><tt>.{@link Path#toUri() toUri}()).equals(</tt> | ||
| 108 | * <i>p</i><tt>.{@link Path#toAbsolutePath() toAbsolutePath}())</tt> | ||
| 109 | * </blockquote> | ||
| 110 | * so long as the original {@code Path}, the {@code URI}, and the new {@code | ||
| 111 | * Path} are all created in (possibly different invocations of) the same | ||
| 112 | * Java virtual machine. Whether other providers make any guarantees is | ||
| 113 | * provider specific and therefore unspecified. | ||
| 114 | * | ||
| 115 | * @param uri | ||
| 116 | * the URI to convert | ||
| 117 | * | ||
| 118 | * @return the resulting {@code Path} | ||
| 119 | * | ||
| 120 | * @throws IllegalArgumentException | ||
| 121 | * if preconditions on the {@code uri} parameter do not hold. The | ||
| 122 | * format of the URI is provider specific. | ||
| 123 | * @throws FileSystemNotFoundException | ||
| 124 | * The file system, identified by the URI, does not exist and | ||
| 125 | * cannot be created automatically, or the provider identified by | ||
| 126 | * the URI's scheme component is not installed | ||
| 127 | * @throws SecurityException | ||
| 128 | * if a security manager is installed and it denies an unspecified | ||
| 129 | * permission to access the file system | ||
| 130 | */ | ||
| 131 | public static Path get(URI uri) { | ||
| 132 | String scheme = uri.getScheme(); | ||
| 133 | if (scheme == null) | ||
| 134 | throw new IllegalArgumentException("Missing scheme"); | ||
| 135 | |||
| 136 | // check for default provider to avoid loading of installed providers | ||
| 137 | if (scheme.equalsIgnoreCase("file")) | ||
| 138 | return FileSystems.getDefault().provider().getPath(uri); | ||
| 139 | |||
| 140 | // try to find provider | ||
| 141 | for (FileSystemProvider provider: FileSystemProvider.installedProviders()) { | ||
| 142 | if (provider.getScheme().equalsIgnoreCase(scheme)) { | ||
| 143 | return provider.getPath(uri); | ||
| 144 | } | ||
| 145 | } | ||
| 146 | |||
| 147 | throw new FileSystemNotFoundException("Provider \"" + scheme + "\" not installed"); | ||
| 148 | } | ||
| 149 | } | ||