1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1998, 2013, 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 import java.lang.annotation.Native; 30 31 /** 32 * Package-private abstract class for the local filesystem abstraction. 33 */ 34 35 abstract class FileSystem { 36 37 /* -- Normalization and construction -- */ 38 39 /** 40 * Return the local filesystem's name-separator character. 41 */ 42 public abstract char getSeparator(); 43 44 /** 45 * Return the local filesystem's path-separator character. 46 */ 47 public abstract char getPathSeparator(); 48 49 /** 50 * Convert the given pathname string to normal form. If the string is 51 * already in normal form then it is simply returned. 52 */ 53 public abstract String normalize(String path); 54 55 /** 56 * Compute the length of this pathname string's prefix. The pathname 57 * string must be in normal form. 58 */ 59 public abstract int prefixLength(String path); 60 61 /** 62 * Resolve the child pathname string against the parent. 63 * Both strings must be in normal form, and the result 64 * will be in normal form. 65 */ 66 public abstract String resolve(String parent, String child); 67 68 /** 69 * Return the parent pathname string to be used when the parent-directory 70 * argument in one of the two-argument File constructors is the empty 71 * pathname. 72 */ 73 public abstract String getDefaultParent(); 74 75 /** 76 * Post-process the given URI path string if necessary. This is used on 77 * win32, e.g., to transform "/c:/foo" into "c:/foo". The path string 78 * still has slash separators; code in the File class will translate them 79 * after this method returns. 80 */ 81 public abstract String fromURIPath(String path); 82 83 84 /* -- Path operations -- */ 85 86 /** 87 * Tell whether or not the given abstract pathname is absolute. 88 */ 89 public abstract boolean isAbsolute(File f); 90 91 /** 92 * Resolve the given abstract pathname into absolute form. Invoked by the 93 * getAbsolutePath and getCanonicalPath methods in the File class. 94 */ 95 public abstract String resolve(File f); 96 97 public abstract String canonicalize(String path) throws IOException; 98 99 100 /* -- Attribute accessors -- */ 101 102 /* Constants for simple boolean attributes */ 103 @Native public static final int BA_EXISTS = 0x01; 104 @Native public static final int BA_REGULAR = 0x02; 105 @Native public static final int BA_DIRECTORY = 0x04; 106 @Native public static final int BA_HIDDEN = 0x08; 107 108 /** 109 * Return the simple boolean attributes for the file or directory denoted 110 * by the given abstract pathname, or zero if it does not exist or some 111 * other I/O error occurs. 112 */ 113 public abstract int getBooleanAttributes(File f); 114 115 @Native public static final int ACCESS_READ = 0x04; 116 @Native public static final int ACCESS_WRITE = 0x02; 117 @Native public static final int ACCESS_EXECUTE = 0x01; 118 public static final int ACCESS_OK = 0x08; 119 120 /** 121 * Check whether the file or directory denoted by the given abstract 122 * pathname may be accessed by this process. The second argument specifies 123 * which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check. 124 * Return false if access is denied or an I/O error occurs 125 */ 126 public abstract boolean checkAccess(File f, int access); 127 /** 128 * Set on or off the access permission (to owner only or to all) to the file 129 * or directory denoted by the given abstract pathname, based on the parameters 130 * enable, access and oweronly. 131 */ 132 public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly); 133 134 /** 135 * Return the time at which the file or directory denoted by the given 136 * abstract pathname was last modified, or zero if it does not exist or 137 * some other I/O error occurs. 138 */ 139 public abstract long getLastModifiedTime(File f); 140 141 /** 142 * Return the length in bytes of the file denoted by the given abstract 143 * pathname, or zero if it does not exist, is a directory, or some other 144 * I/O error occurs. 145 */ 146 public abstract long getLength(File f); 147 148 149 /* -- File operations -- */ 150 151 /** 152 * Create a new empty file with the given pathname. Return 153 * <code>true</code> if the file was created and <code>false</code> if a 154 * file or directory with the given pathname already exists. Throw an 155 * IOException if an I/O error occurs. 156 */ 157 public abstract boolean createFileExclusively(String pathname) 158 throws IOException; 159 160 /** 161 * Delete the file or directory denoted by the given abstract pathname, 162 * returning <code>true</code> if and only if the operation succeeds. 163 */ 164 public abstract boolean delete(File f); 165 166 /** 167 * List the elements of the directory denoted by the given abstract 168 * pathname. Return an array of strings naming the elements of the 169 * directory if successful; otherwise, return <code>null</code>. 170 */ 171 public abstract String[] list(File f); 172 173 /** 174 * Create a new directory denoted by the given abstract pathname, 175 * returning <code>true</code> if and only if the operation succeeds. 176 */ 177 public abstract boolean createDirectory(File f); 178 179 /** 180 * Rename the file or directory denoted by the first abstract pathname to 181 * the second abstract pathname, returning <code>true</code> if and only if 182 * the operation succeeds. 183 */ 184 public abstract boolean rename(File f1, File f2); 185 186 /** 187 * Set the last-modified time of the file or directory denoted by the 188 * given abstract pathname, returning <code>true</code> if and only if the 189 * operation succeeds. 190 */ 191 public abstract boolean setLastModifiedTime(File f, long time); 192 193 /** 194 * Mark the file or directory denoted by the given abstract pathname as 195 * read-only, returning <code>true</code> if and only if the operation 196 * succeeds. 197 */ 198 public abstract boolean setReadOnly(File f); 199 200 201 /* -- Filesystem interface -- */ 202 203 /** 204 * List the available filesystem roots. 205 */ 206 public abstract File[] listRoots(); 207 208 /* -- Disk usage -- */ 209 @Native public static final int SPACE_TOTAL = 0; 210 @Native public static final int SPACE_FREE = 1; 211 @Native public static final int SPACE_USABLE = 2; 212 213 public abstract long getSpace(File f, int t); 214 215 /* -- Basic infrastructure -- */ 216 217 /** 218 * Compare two abstract pathnames lexicographically. 219 */ 220 public abstract int compare(File f1, File f2); 221 222 /** 223 * Compute the hash code of an abstract pathname. 224 */ 225 public abstract int hashCode(File f); 226 227 // Flags for enabling/disabling performance optimizations for file 228 // name canonicalization 229 static boolean useCanonCaches = true; 230 static boolean useCanonPrefixCache = true; 231 232 private static boolean getBooleanProperty(String prop, boolean defaultVal) { 233 String val = System.getProperty(prop); 234 if (val == null) return defaultVal; 235 if (val.equalsIgnoreCase("true")) { 236 return true; 237 } else { 238 return false; 239 } 240 } 241 242 static { 243 useCanonCaches = getBooleanProperty("sun.io.useCanonCaches", 244 useCanonCaches); 245 useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache", 246 useCanonPrefixCache); 247 } 248 } 249
