/* * Copyright (c) 1998, 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.io;  /** * Package-private abstract class for the local filesystem abstraction. */ abstract class FileSystem {     /**     * Return the FileSystem object representing this platform's local     * filesystem.     */    public static native FileSystem getFileSystem();      /* -- Normalization and construction -- */     /**     * Return the local filesystem's name-separator character.     */    public abstract char getSeparator();     /**     * Return the local filesystem's path-separator character.     */    public abstract char getPathSeparator();     /**     * Convert the given pathname string to normal form.  If the string is     * already in normal form then it is simply returned.     */    public abstract String normalize(String path);     /**     * Compute the length of this pathname string's prefix.  The pathname     * string must be in normal form.     */    public abstract int prefixLength(String path);     /**     * Resolve the child pathname string against the parent.     * Both strings must be in normal form, and the result     * will be in normal form.     */    public abstract String resolve(String parent, String child);     /**     * Return the parent pathname string to be used when the parent-directory     * argument in one of the two-argument File constructors is the empty     * pathname.     */    public abstract String getDefaultParent();     /**     * Post-process the given URI path string if necessary.  This is used on     * win32, e.g., to transform "/c:/foo" into "c:/foo".  The path string     * still has slash separators; code in the File class will translate them     * after this method returns.     */    public abstract String fromURIPath(String path);      /* -- Path operations -- */     /**     * Tell whether or not the given abstract pathname is absolute.     */    public abstract boolean isAbsolute(File f);     /**     * Resolve the given abstract pathname into absolute form.  Invoked by the     * getAbsolutePath and getCanonicalPath methods in the File class.     */    public abstract String resolve(File f);     public abstract String canonicalize(String path) throws IOException;      /* -- Attribute accessors -- */     /* Constants for simple boolean attributes */    public static final int BA_EXISTS    = 0x01;    public static final int BA_REGULAR   = 0x02;    public static final int BA_DIRECTORY = 0x04;    public static final int BA_HIDDEN    = 0x08;     /**     * Return the simple boolean attributes for the file or directory denoted     * by the given abstract pathname, or zero if it does not exist or some     * other I/O error occurs.     */    public abstract int getBooleanAttributes(File f);     public static final int ACCESS_READ    = 0x04;    public static final int ACCESS_WRITE   = 0x02;    public static final int ACCESS_EXECUTE = 0x01;     /**     * Check whether the file or directory denoted by the given abstract     * pathname may be accessed by this process.  The second argument specifies     * which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check.     * Return false if access is denied or an I/O error occurs     */    public abstract boolean checkAccess(File f, int access);    /**     * Set on or off the access permission (to owner only or to all) to the file     * or directory denoted by the given abstract pathname, based on the parameters     * enable, access and oweronly.     */    public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly);     /**     * Return the time at which the file or directory denoted by the given     * abstract pathname was last modified, or zero if it does not exist or     * some other I/O error occurs.     */    public abstract long getLastModifiedTime(File f);     /**     * Return the length in bytes of the file denoted by the given abstract     * pathname, or zero if it does not exist, is a directory, or some other     * I/O error occurs.     */    public abstract long getLength(File f);      /* -- File operations -- */     /**     * Create a new empty file with the given pathname.  Return     * <code>true</code> if the file was created and <code>false</code> if a     * file or directory with the given pathname already exists.  Throw an     * IOException if an I/O error occurs.     */    public abstract boolean createFileExclusively(String pathname)        throws IOException;     /**     * Delete the file or directory denoted by the given abstract pathname,     * returning <code>true</code> if and only if the operation succeeds.     */    public abstract boolean delete(File f);     /**     * List the elements of the directory denoted by the given abstract     * pathname.  Return an array of strings naming the elements of the     * directory if successful; otherwise, return <code>null</code>.     */    public abstract String[] list(File f);     /**     * Create a new directory denoted by the given abstract pathname,     * returning <code>true</code> if and only if the operation succeeds.     */    public abstract boolean createDirectory(File f);     /**     * Rename the file or directory denoted by the first abstract pathname to     * the second abstract pathname, returning <code>true</code> if and only if     * the operation succeeds.     */    public abstract boolean rename(File f1, File f2);     /**     * Set the last-modified time of the file or directory denoted by the     * given abstract pathname, returning <code>true</code> if and only if the     * operation succeeds.     */    public abstract boolean setLastModifiedTime(File f, long time);     /**     * Mark the file or directory denoted by the given abstract pathname as     * read-only, returning <code>true</code> if and only if the operation     * succeeds.     */    public abstract boolean setReadOnly(File f);      /* -- Filesystem interface -- */     /**     * List the available filesystem roots.     */    public abstract File[] listRoots();     /* -- Disk usage -- */    public static final int SPACE_TOTAL  = 0;    public static final int SPACE_FREE   = 1;    public static final int SPACE_USABLE = 2;     public abstract long getSpace(File f, int t);     /* -- Basic infrastructure -- */     /**     * Compare two abstract pathnames lexicographically.     */    public abstract int compare(File f1, File f2);     /**     * Compute the hash code of an abstract pathname.     */    public abstract int hashCode(File f);     // Flags for enabling/disabling performance optimizations for file    // name canonicalization    static boolean useCanonCaches      = true;    static boolean useCanonPrefixCache = true;     private static boolean getBooleanProperty(String prop, boolean defaultVal) {        String val = System.getProperty(prop);        if (val == null) return defaultVal;        if (val.equalsIgnoreCase("true")) {            return true;        } else {            return false;        }    }     static {        useCanonCaches      = getBooleanProperty("sun.io.useCanonCaches",                                                 useCanonCaches);        useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache",                                                 useCanonPrefixCache);    }}