1 /*
2  * Copyright (c) 1997, 2019, 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;
27 
28 /**
29  * <p> This interface represents a guard, which is an object that is used
30  * to protect access to another object.
31  *
32  * <p>This interface contains a single method, {@code checkGuard},
33  * with a single {@code object} argument. {@code checkGuard} is
34  * invoked (by the GuardedObject {@code getObject} method)
35  * to determine whether or not to allow access to the object.
36  *
37  * @see GuardedObject
38  *
39  * @author Roland Schemers
40  * @author Li Gong
41  * @since 1.2
42  */
43 
44 public interface Guard {
45 
46     /**
47      * Determines whether or not to allow access to the guarded object
48      * {@code object}. Returns silently if access is allowed.
49      * Otherwise, throws a SecurityException.
50      *
51      * @param object the object being protected by the guard.
52      *
53      * @throws    SecurityException if access is denied.
54      *
55      */
checkGuard(Object object)56     void checkGuard(Object object) throws SecurityException;
57 }
58