1 /*
2 * Copyright (c) 1998, 2013, 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.io;
27
28 import java.lang.annotation.Native;
29
30 /**
31 * Package-private abstract class for the local filesystem abstraction.
32 */
33
34 abstract class FileSystem {
35
36 /* -- Normalization and construction -- */
37
38 /**
39 * Return the local filesystem's name-separator character.
40 */
41 public abstract char getSeparator();
42
43 /**
44 * Return the local filesystem's path-separator character.
45 */
46 public abstract char getPathSeparator();
47
48 /**
49 * Convert the given pathname string to normal form. If the string is
50 * already in normal form then it is simply returned.
51 */
52 public abstract String normalize(String path);
53
54 /**
55 * Compute the length of this pathname string's prefix. The pathname
56 * string must be in normal form.
57 */
58 public abstract int prefixLength(String path);
59
60 /**
61 * Resolve the child pathname string against the parent.
62 * Both strings must be in normal form, and the result
63 * will be in normal form.
64 */
65 public abstract String resolve(String parent, String child);
66
67 /**
68 * Return the parent pathname string to be used when the parent-directory
69 * argument in one of the two-argument File constructors is the empty
70 * pathname.
71 */
72 public abstract String getDefaultParent();
73
74 /**
75 * Post-process the given URI path string if necessary. This is used on
76 * win32, e.g., to transform "/c:/foo" into "c:/foo". The path string
77 * still has slash separators; code in the File class will translate them
78 * after this method returns.
79 */
80 public abstract String fromURIPath(String path);
81
82
83 /* -- Path operations -- */
84
85 /**
86 * Tell whether or not the given abstract pathname is absolute.
87 */
88 public abstract boolean isAbsolute(File f);
89
90 /**
91 * Resolve the given abstract pathname into absolute form. Invoked by the
92 * getAbsolutePath and getCanonicalPath methods in the File class.
93 */
94 public abstract String resolve(File f);
95
96 public abstract String canonicalize(String path) throws IOException;
97
98
99 /* -- Attribute accessors -- */
100
101 /* Constants for simple boolean attributes */
102 @Native public static final int BA_EXISTS = 0x01;
103 @Native public static final int BA_REGULAR = 0x02;
104 @Native public static final int BA_DIRECTORY = 0x04;
105 @Native public static final int BA_HIDDEN = 0x08;
106
107 /**
108 * Return the simple boolean attributes for the file or directory denoted
109 * by the given abstract pathname, or zero if it does not exist or some
110 * other I/O error occurs.
111 */
112 public abstract int getBooleanAttributes(File f);
113
114 @Native public static final int ACCESS_READ = 0x04;
115 @Native public static final int ACCESS_WRITE = 0x02;
116 @Native public static final int ACCESS_EXECUTE = 0x01;
117
118 /**
119 * Check whether the file or directory denoted by the given abstract
120 * pathname may be accessed by this process. The second argument specifies
121 * which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check.
122 * Return false if access is denied or an I/O error occurs
123 */
124 public abstract boolean checkAccess(File f, int access);
125 /**
126 * Set on or off the access permission (to owner only or to all) to the file
127 * or directory denoted by the given abstract pathname, based on the parameters
128 * enable, access and oweronly.
129 */
130 public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly);
131
132 /**
133 * Return the time at which the file or directory denoted by the given
134 * abstract pathname was last modified, or zero if it does not exist or
135 * some other I/O error occurs.
136 */
137 public abstract long getLastModifiedTime(File f);
138
139 /**
140 * Return the length in bytes of the file denoted by the given abstract
141 * pathname, or zero if it does not exist, is a directory, or some other
142 * I/O error occurs.
143 */
144 public abstract long getLength(File f);
145
146
147 /* -- File operations -- */
148
149 /**
150 * Create a new empty file with the given pathname. Return
151 * <code>true</code> if the file was created and <code>false</code> if a
152 * file or directory with the given pathname already exists. Throw an
153 * IOException if an I/O error occurs.
154 */
155 public abstract boolean createFileExclusively(String pathname)
156 throws IOException;
157
158 /**
159 * Delete the file or directory denoted by the given abstract pathname,
160 * returning <code>true</code> if and only if the operation succeeds.
161 */
162 public abstract boolean delete(File f);
163
164 /**
165 * List the elements of the directory denoted by the given abstract
166 * pathname. Return an array of strings naming the elements of the
167 * directory if successful; otherwise, return <code>null</code>.
168 */
169 public abstract String[] list(File f);
170
171 /**
172 * Create a new directory denoted by the given abstract pathname,
173 * returning <code>true</code> if and only if the operation succeeds.
174 */
175 public abstract boolean createDirectory(File f);
176
177 /**
178 * Rename the file or directory denoted by the first abstract pathname to
179 * the second abstract pathname, returning <code>true</code> if and only if
180 * the operation succeeds.
181 */
182 public abstract boolean rename(File f1, File f2);
183
184 /**
185 * Set the last-modified time of the file or directory denoted by the
186 * given abstract pathname, returning <code>true</code> if and only if the
187 * operation succeeds.
188 */
189 public abstract boolean setLastModifiedTime(File f, long time);
190
191 /**
192 * Mark the file or directory denoted by the given abstract pathname as
193 * read-only, returning <code>true</code> if and only if the operation
194 * succeeds.
195 */
196 public abstract boolean setReadOnly(File f);
197
198
199 /* -- Filesystem interface -- */
200
201 /**
202 * List the available filesystem roots.
203 */
204 public abstract File[] listRoots();
205
206 /* -- Disk usage -- */
207 @Native public static final int SPACE_TOTAL = 0;
208 @Native public static final int SPACE_FREE = 1;
209 @Native public static final int SPACE_USABLE = 2;
210
211 public abstract long getSpace(File f, int t);
212
213 /* -- Basic infrastructure -- */
214
215 /**
216 * Compare two abstract pathnames lexicographically.
217 */
218 public abstract int compare(File f1, File f2);
219
220 /**
221 * Compute the hash code of an abstract pathname.
222 */
223 public abstract int hashCode(File f);
224
225 // Flags for enabling/disabling performance optimizations for file
226 // name canonicalization
227 static boolean useCanonCaches = true;
228 static boolean useCanonPrefixCache = true;
229
230 private static boolean getBooleanProperty(String prop, boolean defaultVal) {
231 String val = System.getProperty(prop);
232 if (val == null) return defaultVal;
233 if (val.equalsIgnoreCase("true")) {
234 return true;
235 } else {
236 return false;
237 }
238 }
239
240 // NUL character
241 static final char CHAR_NUL = '\u0000';
242
243 static {
244 useCanonCaches = getBooleanProperty("sun.io.useCanonCaches",
245 useCanonCaches);
246 useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache",
247 useCanonPrefixCache);
248 }
249 }