1 /*
2 * Copyright 1996-2004 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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</code> 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 }
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