001: /*
002: * Copyright 1998-2005 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025:
026: package java.io;
027:
028: /**
029: * Package-private abstract class for the local filesystem abstraction.
030: */
031:
032: abstract class FileSystem {
033:
034: /**
035: * Return the FileSystem object representing this platform's local
036: * filesystem.
037: */
038: public static native FileSystem getFileSystem();
039:
040: /* -- Normalization and construction -- */
041:
042: /**
043: * Return the local filesystem's name-separator character.
044: */
045: public abstract char getSeparator();
046:
047: /**
048: * Return the local filesystem's path-separator character.
049: */
050: public abstract char getPathSeparator();
051:
052: /**
053: * Convert the given pathname string to normal form. If the string is
054: * already in normal form then it is simply returned.
055: */
056: public abstract String normalize(String path);
057:
058: /**
059: * Compute the length of this pathname string's prefix. The pathname
060: * string must be in normal form.
061: */
062: public abstract int prefixLength(String path);
063:
064: /**
065: * Resolve the child pathname string against the parent.
066: * Both strings must be in normal form, and the result
067: * will be in normal form.
068: */
069: public abstract String resolve(String parent, String child);
070:
071: /**
072: * Return the parent pathname string to be used when the parent-directory
073: * argument in one of the two-argument File constructors is the empty
074: * pathname.
075: */
076: public abstract String getDefaultParent();
077:
078: /**
079: * Post-process the given URI path string if necessary. This is used on
080: * win32, e.g., to transform "/c:/foo" into "c:/foo". The path string
081: * still has slash separators; code in the File class will translate them
082: * after this method returns.
083: */
084: public abstract String fromURIPath(String path);
085:
086: /* -- Path operations -- */
087:
088: /**
089: * Tell whether or not the given abstract pathname is absolute.
090: */
091: public abstract boolean isAbsolute(File f);
092:
093: /**
094: * Resolve the given abstract pathname into absolute form. Invoked by the
095: * getAbsolutePath and getCanonicalPath methods in the File class.
096: */
097: public abstract String resolve(File f);
098:
099: public abstract String canonicalize(String path) throws IOException;
100:
101: /* -- Attribute accessors -- */
102:
103: /* Constants for simple boolean attributes */
104: public static final int BA_EXISTS = 0x01;
105: public static final int BA_REGULAR = 0x02;
106: public static final int BA_DIRECTORY = 0x04;
107: public static final int BA_HIDDEN = 0x08;
108:
109: /**
110: * Return the simple boolean attributes for the file or directory denoted
111: * by the given abstract pathname, or zero if it does not exist or some
112: * other I/O error occurs.
113: */
114: public abstract int getBooleanAttributes(File f);
115:
116: public static final int ACCESS_READ = 0x04;
117: public static final int ACCESS_WRITE = 0x02;
118: public static final int ACCESS_EXECUTE = 0x01;
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: /**
129: * Set on or off the access permission (to owner only or to all) to the file
130: * or directory denoted by the given abstract pathname, based on the parameters
131: * enable, access and oweronly.
132: */
133: public abstract boolean setPermission(File f, int access,
134: boolean enable, boolean owneronly);
135:
136: /**
137: * Return the time at which the file or directory denoted by the given
138: * abstract pathname was last modified, or zero if it does not exist or
139: * some other I/O error occurs.
140: */
141: public abstract long getLastModifiedTime(File f);
142:
143: /**
144: * Return the length in bytes of the file denoted by the given abstract
145: * pathname, or zero if it does not exist, is a directory, or some other
146: * I/O error occurs.
147: */
148: public abstract long getLength(File f);
149:
150: /* -- File operations -- */
151:
152: /**
153: * Create a new empty file with the given pathname. Return
154: * <code>true</code> if the file was created and <code>false</code> if a
155: * file or directory with the given pathname already exists. Throw an
156: * IOException if an I/O error occurs.
157: */
158: public abstract boolean createFileExclusively(String pathname)
159: throws IOException;
160:
161: /**
162: * Delete the file or directory denoted by the given abstract pathname,
163: * returning <code>true</code> if and only if the operation succeeds.
164: */
165: public abstract boolean delete(File f);
166:
167: /**
168: * List the elements of the directory denoted by the given abstract
169: * pathname. Return an array of strings naming the elements of the
170: * directory if successful; otherwise, return <code>null</code>.
171: */
172: public abstract String[] list(File f);
173:
174: /**
175: * Create a new directory denoted by the given abstract pathname,
176: * returning <code>true</code> if and only if the operation succeeds.
177: */
178: public abstract boolean createDirectory(File f);
179:
180: /**
181: * Rename the file or directory denoted by the first abstract pathname to
182: * the second abstract pathname, returning <code>true</code> if and only if
183: * the operation succeeds.
184: */
185: public abstract boolean rename(File f1, File f2);
186:
187: /**
188: * Set the last-modified time of the file or directory denoted by the
189: * given abstract pathname, returning <code>true</code> if and only if the
190: * operation succeeds.
191: */
192: public abstract boolean setLastModifiedTime(File f, long time);
193:
194: /**
195: * Mark the file or directory denoted by the given abstract pathname as
196: * read-only, returning <code>true</code> if and only if the operation
197: * succeeds.
198: */
199: public abstract boolean setReadOnly(File f);
200:
201: /* -- Filesystem interface -- */
202:
203: /**
204: * List the available filesystem roots.
205: */
206: public abstract File[] listRoots();
207:
208: /* -- Disk usage -- */
209: public static final int SPACE_TOTAL = 0;
210: public static final int SPACE_FREE = 1;
211: 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,
233: boolean defaultVal) {
234: String val = System.getProperty(prop);
235: if (val == null)
236: return defaultVal;
237: if (val.equalsIgnoreCase("true")) {
238: return true;
239: } else {
240: return false;
241: }
242: }
243:
244: static {
245: useCanonCaches = getBooleanProperty("sun.io.useCanonCaches",
246: useCanonCaches);
247: useCanonPrefixCache = getBooleanProperty(
248: "sun.io.useCanonPrefixCache", useCanonPrefixCache);
249: }
250: }
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