1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1998, 2005, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27 package java.io; 28 29 30 /** 31 * Package-private abstract class for the local filesystem abstraction. 32 */ 33 34 abstract class FileSystem { 35 36 /** 37 * Return the FileSystem object representing this platform's local 38 * filesystem. 39 */ 40 public static native FileSystem getFileSystem(); 41 42 43 /* -- Normalization and construction -- */ 44 45 /** 46 * Return the local filesystem's name-separator character. 47 */ 48 public abstract char getSeparator(); 49 50 /** 51 * Return the local filesystem's path-separator character. 52 */ 53 public abstract char getPathSeparator(); 54 55 /** 56 * Convert the given pathname string to normal form. If the string is 57 * already in normal form then it is simply returned. 58 */ 59 public abstract String normalize(String path); 60 61 /** 62 * Compute the length of this pathname string's prefix. The pathname 63 * string must be in normal form. 64 */ 65 public abstract int prefixLength(String path); 66 67 /** 68 * Resolve the child pathname string against the parent. 69 * Both strings must be in normal form, and the result 70 * will be in normal form. 71 */ 72 public abstract String resolve(String parent, String child); 73 74 /** 75 * Return the parent pathname string to be used when the parent-directory 76 * argument in one of the two-argument File constructors is the empty 77 * pathname. 78 */ 79 public abstract String getDefaultParent(); 80 81 /** 82 * Post-process the given URI path string if necessary. This is used on 83 * win32, e.g., to transform "/c:/foo" into "c:/foo". The path string 84 * still has slash separators; code in the File class will translate them 85 * after this method returns. 86 */ 87 public abstract String fromURIPath(String path); 88 89 90 /* -- Path operations -- */ 91 92 /** 93 * Tell whether or not the given abstract pathname is absolute. 94 */ 95 public abstract boolean isAbsolute(File f); 96 97 /** 98 * Resolve the given abstract pathname into absolute form. Invoked by the 99 * getAbsolutePath and getCanonicalPath methods in the File class. 100 */ 101 public abstract String resolve(File f); 102 103 public abstract String canonicalize(String path) throws IOException; 104 105 106 /* -- Attribute accessors -- */ 107 108 /* Constants for simple boolean attributes */ 109 public static final int BA_EXISTS = 0x01; 110 public static final int BA_REGULAR = 0x02; 111 public static final int BA_DIRECTORY = 0x04; 112 public static final int BA_HIDDEN = 0x08; 113 114 /** 115 * Return the simple boolean attributes for the file or directory denoted 116 * by the given abstract pathname, or zero if it does not exist or some 117 * other I/O error occurs. 118 */ 119 public abstract int getBooleanAttributes(File f); 120 121 public static final int ACCESS_READ = 0x04; 122 public static final int ACCESS_WRITE = 0x02; 123 public static final int ACCESS_EXECUTE = 0x01; 124 public static final int ACCESS_OK = 0x08; 125 126 /** 127 * Check whether the file or directory denoted by the given abstract 128 * pathname may be accessed by this process. The second argument specifies 129 * which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check. 130 * Return false if access is denied or an I/O error occurs 131 */ 132 public abstract boolean checkAccess(File f, int access); 133 /** 134 * Set on or off the access permission (to owner only or to all) to the file 135 * or directory denoted by the given abstract pathname, based on the parameters 136 * enable, access and oweronly. 137 */ 138 public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly); 139 140 /** 141 * Return the time at which the file or directory denoted by the given 142 * abstract pathname was last modified, or zero if it does not exist or 143 * some other I/O error occurs. 144 */ 145 public abstract long getLastModifiedTime(File f); 146 147 /** 148 * Return the length in bytes of the file denoted by the given abstract 149 * pathname, or zero if it does not exist, is a directory, or some other 150 * I/O error occurs. 151 */ 152 public abstract long getLength(File f); 153 154 155 /* -- File operations -- */ 156 157 /** 158 * Create a new empty file with the given pathname. Return 159 * <code>true</code> if the file was created and <code>false</code> if a 160 * file or directory with the given pathname already exists. Throw an 161 * IOException if an I/O error occurs. 162 */ 163 public abstract boolean createFileExclusively(String pathname) 164 throws IOException; 165 166 /** 167 * Delete the file or directory denoted by the given abstract pathname, 168 * returning <code>true</code> if and only if the operation succeeds. 169 */ 170 public abstract boolean delete(File f); 171 172 /** 173 * List the elements of the directory denoted by the given abstract 174 * pathname. Return an array of strings naming the elements of the 175 * directory if successful; otherwise, return <code>null</code>. 176 */ 177 public abstract String[] list(File f); 178 179 /** 180 * Create a new directory denoted by the given abstract pathname, 181 * returning <code>true</code> if and only if the operation succeeds. 182 */ 183 public abstract boolean createDirectory(File f); 184 185 /** 186 * Rename the file or directory denoted by the first abstract pathname to 187 * the second abstract pathname, returning <code>true</code> if and only if 188 * the operation succeeds. 189 */ 190 public abstract boolean rename(File f1, File f2); 191 192 /** 193 * Set the last-modified time of the file or directory denoted by the 194 * given abstract pathname, returning <code>true</code> if and only if the 195 * operation succeeds. 196 */ 197 public abstract boolean setLastModifiedTime(File f, long time); 198 199 /** 200 * Mark the file or directory denoted by the given abstract pathname as 201 * read-only, returning <code>true</code> if and only if the operation 202 * succeeds. 203 */ 204 public abstract boolean setReadOnly(File f); 205 206 207 /* -- Filesystem interface -- */ 208 209 /** 210 * List the available filesystem roots. 211 */ 212 public abstract File[] listRoots(); 213 214 /* -- Disk usage -- */ 215 public static final int SPACE_TOTAL = 0; 216 public static final int SPACE_FREE = 1; 217 public static final int SPACE_USABLE = 2; 218 219 public abstract long getSpace(File f, int t); 220 221 /* -- Basic infrastructure -- */ 222 223 /** 224 * Compare two abstract pathnames lexicographically. 225 */ 226 public abstract int compare(File f1, File f2); 227 228 /** 229 * Compute the hash code of an abstract pathname. 230 */ 231 public abstract int hashCode(File f); 232 233 // Flags for enabling/disabling performance optimizations for file 234 // name canonicalization 235 static boolean useCanonCaches = true; 236 static boolean useCanonPrefixCache = true; 237 238 private static boolean getBooleanProperty(String prop, boolean defaultVal) { 239 String val = System.getProperty(prop); 240 if (val == null) return defaultVal; 241 if (val.equalsIgnoreCase("true")) { 242 return true; 243 } else { 244 return false; 245 } 246 } 247 248 static { 249 useCanonCaches = getBooleanProperty("sun.io.useCanonCaches", 250 useCanonCaches); 251 useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache", 252 useCanonPrefixCache); 253 } 254 } 255
