/*

 * Copyright (c) 2007, 2011, 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

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 */

package java.nio.file.attribute;

import java.io.IOException;

/**

 * A file attribute view that supports reading or updating the owner of a file.

 * This file attribute view is intended for file system implementations that

 * support a file attribute that represents an identity that is the owner of

 * the file. Often the owner of a file is the identity of the entity that

 * created the file.

 *

 * <p> The {@link #getOwner getOwner} or {@link #setOwner setOwner} methods may

 * be used to read or update the owner of the file.

 *

 * <p> The {@link java.nio.file.Files#getAttribute getAttribute} and

 * {@link java.nio.file.Files#setAttribute setAttribute} methods may also be

 * used to read or update the owner. In that case, the owner attribute is

 * identified by the name {@code "owner"}, and the value of the attribute is

 * a {@link UserPrincipal}.

 *

 * @since 1.7

 */

public interface FileOwnerAttributeView

    extends FileAttributeView

{

    /**

     * Returns the name of the attribute view. Attribute views of this type

     * have the name {@code "owner"}.

     */

    @Override

    String name();

    /**

     * Read the file owner.

     *

     * <p> It it implementation specific if the file owner can be a {@link

     * GroupPrincipal group}.

     *

     * @return  the file owner

     *

     * @throws  IOException

     *          if an I/O error occurs

     * @throws  SecurityException

     *          In the case of the default provider, a security manager is

     *          installed, and it denies {@link

     *          RuntimePermission}<tt>("accessUserInformation")</tt> or its

     *          {@link SecurityManager#checkRead(String) checkRead} method

     *          denies read access to the file.

     */

    UserPrincipal getOwner() throws IOException;

    /**

     * Updates the file owner.

     *

     * <p> It it implementation specific if the file owner can be a {@link

     * GroupPrincipal group}. To ensure consistent and correct behavior

     * across platforms it is recommended that this method should only be used

     * to set the file owner to a user principal that is not a group.

     *

     * @param   owner

     *          the new file owner

     *

     * @throws  IOException

     *          if an I/O error occurs, or the {@code owner} parameter is a

     *          group and this implementation does not support setting the owner

     *          to a group

     * @throws  SecurityException

     *          In the case of the default provider, a security manager is

     *          installed, and it denies {@link

     *          RuntimePermission}<tt>("accessUserInformation")</tt> or its

     *          {@link SecurityManager#checkWrite(String) checkWrite} method

     *          denies write access to the file.

     */

    void setOwner(UserPrincipal owner) throws IOException;

}