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	/*
	* Copyright (c) 1998, 2013, 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;

	import java.lang.annotation.Native;

	/**
	* Package-private abstract class for the local filesystem abstraction.
	*/

	abstract class FileSystem {

	/* -- 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 */
	@Native public static final int BA_EXISTS = 0x01;
	@Native public static final int BA_REGULAR = 0x02;
	@Native public static final int BA_DIRECTORY = 0x04;
	@Native 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);

	@Native public static final int ACCESS_READ = 0x04;
	@Native public static final int ACCESS_WRITE = 0x02;
	@Native 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 -- */
	@Native public static final int SPACE_TOTAL = 0;
	@Native public static final int SPACE_FREE = 1;
	@Native 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);
	}
	}

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