jdk/src/share/classes/java/io/FileSystem.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/io/FileSystem.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,252 @@
+/*
+ * Copyright 1998-2005 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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);
+    }
+}