[120] | 1 | /** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | |
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| 19 | package org.apache.hadoop.fs; |
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| 20 | |
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| 21 | import java.net.*; |
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| 22 | import java.io.*; |
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| 23 | |
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| 24 | import org.apache.hadoop.conf.Configuration; |
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| 25 | |
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| 26 | /** Names a file or directory in a {@link FileSystem}. |
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| 27 | * Path strings use slash as the directory separator. A path string is |
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| 28 | * absolute if it begins with a slash. |
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| 29 | */ |
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| 30 | public class Path implements Comparable { |
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| 31 | |
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| 32 | /** The directory separator, a slash. */ |
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| 33 | public static final String SEPARATOR = "/"; |
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| 34 | public static final char SEPARATOR_CHAR = '/'; |
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| 35 | |
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| 36 | public static final String CUR_DIR = "."; |
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| 37 | |
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| 38 | static final boolean WINDOWS |
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| 39 | = System.getProperty("os.name").startsWith("Windows"); |
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| 40 | |
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| 41 | private URI uri; // a hierarchical uri |
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| 42 | |
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| 43 | /** Resolve a child path against a parent path. */ |
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| 44 | public Path(String parent, String child) { |
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| 45 | this(new Path(parent), new Path(child)); |
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| 46 | } |
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| 47 | |
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| 48 | /** Resolve a child path against a parent path. */ |
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| 49 | public Path(Path parent, String child) { |
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| 50 | this(parent, new Path(child)); |
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| 51 | } |
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| 52 | |
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| 53 | /** Resolve a child path against a parent path. */ |
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| 54 | public Path(String parent, Path child) { |
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| 55 | this(new Path(parent), child); |
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| 56 | } |
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| 57 | |
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| 58 | /** Resolve a child path against a parent path. */ |
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| 59 | public Path(Path parent, Path child) { |
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| 60 | // Add a slash to parent's path so resolution is compatible with URI's |
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| 61 | URI parentUri = parent.uri; |
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| 62 | String parentPath = parentUri.getPath(); |
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| 63 | if (!(parentPath.equals("/") || parentPath.equals(""))) |
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| 64 | try { |
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| 65 | parentUri = new URI(parentUri.getScheme(), parentUri.getAuthority(), |
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| 66 | parentUri.getPath()+"/", null, null); |
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| 67 | } catch (URISyntaxException e) { |
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| 68 | throw new IllegalArgumentException(e); |
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| 69 | } |
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| 70 | URI resolved = parentUri.resolve(child.uri); |
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| 71 | initialize(resolved.getScheme(), resolved.getAuthority(), |
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| 72 | normalizePath(resolved.getPath())); |
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| 73 | } |
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| 74 | |
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| 75 | private void checkPathArg( String path ) { |
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| 76 | // disallow construction of a Path from an empty string |
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| 77 | if ( path == null ) { |
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| 78 | throw new IllegalArgumentException( |
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| 79 | "Can not create a Path from a null string"); |
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| 80 | } |
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| 81 | if( path.length() == 0 ) { |
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| 82 | throw new IllegalArgumentException( |
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| 83 | "Can not create a Path from an empty string"); |
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| 84 | } |
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| 85 | } |
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| 86 | |
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| 87 | /** Construct a path from a String. Path strings are URIs, but with |
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| 88 | * unescaped elements and some additional normalization. */ |
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| 89 | public Path(String pathString) { |
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| 90 | checkPathArg( pathString ); |
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| 91 | |
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| 92 | // We can't use 'new URI(String)' directly, since it assumes things are |
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| 93 | // escaped, which we don't require of Paths. |
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| 94 | |
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| 95 | // add a slash in front of paths with Windows drive letters |
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| 96 | if (hasWindowsDrive(pathString, false)) |
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| 97 | pathString = "/"+pathString; |
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| 98 | |
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| 99 | // parse uri components |
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| 100 | String scheme = null; |
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| 101 | String authority = null; |
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| 102 | |
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| 103 | int start = 0; |
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| 104 | |
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| 105 | // parse uri scheme, if any |
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| 106 | int colon = pathString.indexOf(':'); |
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| 107 | int slash = pathString.indexOf('/'); |
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| 108 | if ((colon != -1) && |
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| 109 | ((slash == -1) || (colon < slash))) { // has a scheme |
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| 110 | scheme = pathString.substring(0, colon); |
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| 111 | start = colon+1; |
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| 112 | } |
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| 113 | |
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| 114 | // parse uri authority, if any |
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| 115 | if (pathString.startsWith("//", start) && |
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| 116 | (pathString.length()-start > 2)) { // has authority |
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| 117 | int nextSlash = pathString.indexOf('/', start+2); |
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| 118 | int authEnd = nextSlash > 0 ? nextSlash : pathString.length(); |
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| 119 | authority = pathString.substring(start+2, authEnd); |
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| 120 | start = authEnd; |
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| 121 | } |
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| 122 | |
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| 123 | // uri path is the rest of the string -- query & fragment not supported |
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| 124 | String path = pathString.substring(start, pathString.length()); |
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| 125 | |
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| 126 | initialize(scheme, authority, path); |
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| 127 | } |
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| 128 | |
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| 129 | /** Construct a Path from components. */ |
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| 130 | public Path(String scheme, String authority, String path) { |
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| 131 | checkPathArg( path ); |
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| 132 | initialize(scheme, authority, path); |
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| 133 | } |
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| 134 | |
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| 135 | private void initialize(String scheme, String authority, String path) { |
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| 136 | try { |
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| 137 | this.uri = new URI(scheme, authority, normalizePath(path), null, null) |
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| 138 | .normalize(); |
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| 139 | } catch (URISyntaxException e) { |
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| 140 | throw new IllegalArgumentException(e); |
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| 141 | } |
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| 142 | } |
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| 143 | |
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| 144 | private String normalizePath(String path) { |
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| 145 | // remove double slashes & backslashes |
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| 146 | path = path.replace("//", "/"); |
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| 147 | path = path.replace("\\", "/"); |
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| 148 | |
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| 149 | // trim trailing slash from non-root path (ignoring windows drive) |
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| 150 | int minLength = hasWindowsDrive(path, true) ? 4 : 1; |
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| 151 | if (path.length() > minLength && path.endsWith("/")) { |
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| 152 | path = path.substring(0, path.length()-1); |
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| 153 | } |
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| 154 | |
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| 155 | return path; |
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| 156 | } |
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| 157 | |
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| 158 | private boolean hasWindowsDrive(String path, boolean slashed) { |
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| 159 | if (!WINDOWS) return false; |
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| 160 | int start = slashed ? 1 : 0; |
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| 161 | return |
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| 162 | path.length() >= start+2 && |
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| 163 | (slashed ? path.charAt(0) == '/' : true) && |
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| 164 | path.charAt(start+1) == ':' && |
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| 165 | ((path.charAt(start) >= 'A' && path.charAt(start) <= 'Z') || |
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| 166 | (path.charAt(start) >= 'a' && path.charAt(start) <= 'z')); |
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| 167 | } |
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| 168 | |
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| 169 | |
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| 170 | /** Convert this to a URI. */ |
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| 171 | public URI toUri() { return uri; } |
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| 172 | |
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| 173 | /** Return the FileSystem that owns this Path. */ |
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| 174 | public FileSystem getFileSystem(Configuration conf) throws IOException { |
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| 175 | return FileSystem.get(this.toUri(), conf); |
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| 176 | } |
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| 177 | |
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| 178 | /** True if the directory of this path is absolute. */ |
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| 179 | public boolean isAbsolute() { |
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| 180 | int start = hasWindowsDrive(uri.getPath(), true) ? 3 : 0; |
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| 181 | return uri.getPath().startsWith(SEPARATOR, start); |
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| 182 | } |
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| 183 | |
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| 184 | /** Returns the final component of this path.*/ |
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| 185 | public String getName() { |
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| 186 | String path = uri.getPath(); |
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| 187 | int slash = path.lastIndexOf(SEPARATOR); |
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| 188 | return path.substring(slash+1); |
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| 189 | } |
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| 190 | |
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| 191 | /** Returns the parent of a path or null if at root. */ |
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| 192 | public Path getParent() { |
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| 193 | String path = uri.getPath(); |
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| 194 | int lastSlash = path.lastIndexOf('/'); |
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| 195 | int start = hasWindowsDrive(path, true) ? 3 : 0; |
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| 196 | if ((path.length() == start) || // empty path |
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| 197 | (lastSlash == start && path.length() == start+1)) { // at root |
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| 198 | return null; |
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| 199 | } |
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| 200 | String parent; |
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| 201 | if (lastSlash==-1) { |
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| 202 | parent = CUR_DIR; |
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| 203 | } else { |
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| 204 | int end = hasWindowsDrive(path, true) ? 3 : 0; |
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| 205 | parent = path.substring(0, lastSlash==end?end+1:lastSlash); |
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| 206 | } |
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| 207 | return new Path(uri.getScheme(), uri.getAuthority(), parent); |
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| 208 | } |
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| 209 | |
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| 210 | /** Adds a suffix to the final name in the path.*/ |
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| 211 | public Path suffix(String suffix) { |
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| 212 | return new Path(getParent(), getName()+suffix); |
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| 213 | } |
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| 214 | |
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| 215 | public String toString() { |
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| 216 | // we can't use uri.toString(), which escapes everything, because we want |
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| 217 | // illegal characters unescaped in the string, for glob processing, etc. |
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| 218 | StringBuffer buffer = new StringBuffer(); |
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| 219 | if (uri.getScheme() != null) { |
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| 220 | buffer.append(uri.getScheme()); |
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| 221 | buffer.append(":"); |
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| 222 | } |
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| 223 | if (uri.getAuthority() != null) { |
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| 224 | buffer.append("//"); |
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| 225 | buffer.append(uri.getAuthority()); |
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| 226 | } |
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| 227 | if (uri.getPath() != null) { |
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| 228 | String path = uri.getPath(); |
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| 229 | if (path.indexOf('/')==0 && |
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| 230 | hasWindowsDrive(path, true) && // has windows drive |
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| 231 | uri.getScheme() == null && // but no scheme |
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| 232 | uri.getAuthority() == null) // or authority |
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| 233 | path = path.substring(1); // remove slash before drive |
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| 234 | buffer.append(path); |
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| 235 | } |
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| 236 | return buffer.toString(); |
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| 237 | } |
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| 238 | |
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| 239 | public boolean equals(Object o) { |
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| 240 | if (!(o instanceof Path)) { |
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| 241 | return false; |
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| 242 | } |
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| 243 | Path that = (Path)o; |
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| 244 | return this.uri.equals(that.uri); |
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| 245 | } |
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| 246 | |
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| 247 | public int hashCode() { |
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| 248 | return uri.hashCode(); |
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| 249 | } |
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| 250 | |
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| 251 | public int compareTo(Object o) { |
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| 252 | Path that = (Path)o; |
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| 253 | return this.uri.compareTo(that.uri); |
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| 254 | } |
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| 255 | |
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| 256 | /** Return the number of elements in this path. */ |
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| 257 | public int depth() { |
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| 258 | String path = uri.getPath(); |
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| 259 | int depth = 0; |
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| 260 | int slash = path.length()==1 && path.charAt(0)=='/' ? -1 : 0; |
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| 261 | while (slash != -1) { |
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| 262 | depth++; |
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| 263 | slash = path.indexOf(SEPARATOR, slash+1); |
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| 264 | } |
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| 265 | return depth; |
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| 266 | } |
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| 267 | |
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| 268 | /** Returns a qualified path object. */ |
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| 269 | public Path makeQualified(FileSystem fs) { |
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| 270 | Path path = this; |
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| 271 | if (!isAbsolute()) { |
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| 272 | path = new Path(fs.getWorkingDirectory(), this); |
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| 273 | } |
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| 274 | |
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| 275 | URI pathUri = path.toUri(); |
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| 276 | URI fsUri = fs.getUri(); |
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| 277 | |
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| 278 | String scheme = pathUri.getScheme(); |
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| 279 | String authority = pathUri.getAuthority(); |
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| 280 | |
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| 281 | if (scheme != null && |
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| 282 | (authority != null || fsUri.getAuthority() == null)) |
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| 283 | return path; |
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| 284 | |
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| 285 | if (scheme == null) { |
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| 286 | scheme = fsUri.getScheme(); |
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| 287 | } |
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| 288 | |
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| 289 | if (authority == null) { |
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| 290 | authority = fsUri.getAuthority(); |
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| 291 | if (authority == null) { |
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| 292 | authority = ""; |
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| 293 | } |
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| 294 | } |
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| 295 | |
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| 296 | return new Path(scheme+":"+"//"+authority + pathUri.getPath()); |
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| 297 | } |
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| 298 | } |
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