1/*
2 * Copyright (c) 1999, 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
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24 */
25
26package com.sun.security.auth;
27
28/**
29 * An object that implements the {@code java.security.Principal}
30 * interface typically also implements this interface to provide
31 * a means for comparing that object to a specified {@code Subject}.
32 *
33 * <p> The comparison is achieved via the {@code implies} method.
34 * The implementation of the {@code implies} method determines
35 * whether this object "implies" the specified {@code Subject}.
36 * One example application of this method may be for
37 * a "group" object to imply a particular {@code Subject}
38 * if that {@code Subject} belongs to the group.
39 * Another example application of this method would be for
40 * "role" object to imply a particular {@code Subject}
41 * if that {@code Subject} is currently acting in that role.
42 *
43 * <p> Although classes that implement this interface typically
44 * also implement the {@code java.security.Principal} interface,
45 * it is not required.  In other words, classes may implement the
46 * {@code java.security.Principal} interface by itself,
47 * the {@code PrincipalComparator} interface by itself,
48 * or both at the same time.
49 *
50 * @see java.security.Principal
51 * @see javax.security.auth.Subject
52 */
53public interface PrincipalComparator {
54    /**
55     * Check if the specified {@code Subject} is implied by
56     * this object.
57     *
58     * @return true if the specified {@code Subject} is implied by
59     *          this object, or false otherwise.
60     */
61    boolean implies(javax.security.auth.Subject subject);
62}
63