1 /*

     2  * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package java.security.acl;

    27 

    28 import java.util.Enumeration;

    29 import java.security.Principal;

    30 

    31 /**

    32  * This interface is used to represent a group of principals. (A principal

    33  * represents an entity such as an individual user or a company). <p>

    34  *

    35  * Note that Group extends Principal. Thus, either a Principal or a Group can

    36  * be passed as an argument to methods containing a Principal parameter. For

    37  * example, you can add either a Principal or a Group to a Group object by

    38  * calling the object's {@code addMember} method, passing it the

    39  * Principal or Group.

    40  *

    41  * @author      Satish Dharmaraj

    42  */

    43 public interface Group extends Principal {

    44 

    45     /**

    46      * Adds the specified member to the group.

    47      *

    48      * @param user the principal to add to this group.

    49      *

    50      * @return true if the member was successfully added,

    51      * false if the principal was already a member.

    52      */

    53     public boolean addMember(Principal user);

    54 

    55     /**

    56      * Removes the specified member from the group.

    57      *

    58      * @param user the principal to remove from this group.

    59      *

    60      * @return true if the principal was removed, or

    61      * false if the principal was not a member.

    62      */

    63     public boolean removeMember(Principal user);

    64 

    65     /**

    66      * Returns true if the passed principal is a member of the group.

    67      * This method does a recursive search, so if a principal belongs to a

    68      * group which is a member of this group, true is returned.

    69      *

    70      * @param member the principal whose membership is to be checked.

    71      *

    72      * @return true if the principal is a member of this group,

    73      * false otherwise.

    74      */

    75     public boolean isMember(Principal member);

    76 

    77 

    78     /**

    79      * Returns an enumeration of the members in the group.

    80      * The returned objects can be instances of either Principal

    81      * or Group (which is a subclass of Principal).

    82      *

    83      * @return an enumeration of the group members.

    84      */

    85     public Enumeration<? extends Principal> members();

    86 

    87 }