/*

 * Copyright (c) 2004, 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 jdk.internal.agent;

import java.io.File;

import java.io.IOException;

/*

 * Utility class to support file system operations

 *

 * @since 1.5

 */

public abstract class FileSystem {

    private static final Object lock = new Object();

    private static FileSystem fs;

    protected FileSystem() { }

    /**

     * Opens the file system

     */

    public static FileSystem open() {

        synchronized (lock) {

            if (fs == null) {

                fs = new FileSystemImpl();

            }

            return fs;

        }

    }

    /**

     * Tells whether or not the specified file is located on a

     * file system that supports file security or not.

     *

     * @throws  IOException     if an I/O error occurs.

     */

    public abstract boolean supportsFileSecurity(File f) throws IOException;

    /**

     * Tell whether or not the specified file is accessible

     * by anything other than the file owner.

     *

     * @throws  IOException     if an I/O error occurs.

     *

     * @throws  UnsupportedOperationException

     *          If file is located on a file system that doesn't support

     *          file security.

     */

    public abstract boolean isAccessUserOnly(File f) throws IOException;

}