1/*
2 * Copyright (c) 2005, 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
26
27package java.security;
28
29/**
30 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
31 * for the <code>Policy</code> class.
32 * All the abstract methods in this class must be implemented by each
33 * service provider who wishes to supply a Policy implementation.
34 *
35 * <p> Subclass implementations of this abstract class must provide
36 * a public constructor that takes a <code>Policy.Parameters</code>
37 * object as an input parameter.  This constructor also must throw
38 * an IllegalArgumentException if it does not understand the
39 * <code>Policy.Parameters</code> input.
40 *
41 *
42 * @since 1.6
43 */
44
45public abstract class PolicySpi {
46
47    /**
48     * Check whether the policy has granted a Permission to a ProtectionDomain.
49     *
50     * @param domain the ProtectionDomain to check.
51     *
52     * @param permission check whether this permission is granted to the
53     *          specified domain.
54     *
55     * @return boolean true if the permission is granted to the domain.
56     */
57    protected abstract boolean engineImplies
58        (ProtectionDomain domain, Permission permission);
59
60    /**
61     * Refreshes/reloads the policy configuration. The behavior of this method
62     * depends on the implementation. For example, calling <code>refresh</code>
63     * on a file-based policy will cause the file to be re-read.
64     *
65     * <p> The default implementation of this method does nothing.
66     * This method should be overridden if a refresh operation is supported
67     * by the policy implementation.
68     */
69    protected void engineRefresh() { }
70
71    /**
72     * Return a PermissionCollection object containing the set of
73     * permissions granted to the specified CodeSource.
74     *
75     * <p> The default implementation of this method returns
76     * Policy.UNSUPPORTED_EMPTY_COLLECTION object.  This method can be
77     * overridden if the policy implementation can return a set of
78     * permissions granted to a CodeSource.
79     *
80     * @param codesource the CodeSource to which the returned
81     *          PermissionCollection has been granted.
82     *
83     * @return a set of permissions granted to the specified CodeSource.
84     *          If this operation is supported, the returned
85     *          set of permissions must be a new mutable instance
86     *          and it must support heterogeneous Permission types.
87     *          If this operation is not supported,
88     *          Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
89     */
90    protected PermissionCollection engineGetPermissions
91                                        (CodeSource codesource) {
92        return Policy.UNSUPPORTED_EMPTY_COLLECTION;
93    }
94
95    /**
96     * Return a PermissionCollection object containing the set of
97     * permissions granted to the specified ProtectionDomain.
98     *
99     * <p> The default implementation of this method returns
100     * Policy.UNSUPPORTED_EMPTY_COLLECTION object.  This method can be
101     * overridden if the policy implementation can return a set of
102     * permissions granted to a ProtectionDomain.
103     *
104     * @param domain the ProtectionDomain to which the returned
105     *          PermissionCollection has been granted.
106     *
107     * @return a set of permissions granted to the specified ProtectionDomain.
108     *          If this operation is supported, the returned
109     *          set of permissions must be a new mutable instance
110     *          and it must support heterogeneous Permission types.
111     *          If this operation is not supported,
112     *          Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
113     */
114    protected PermissionCollection engineGetPermissions
115                                        (ProtectionDomain domain) {
116        return Policy.UNSUPPORTED_EMPTY_COLLECTION;
117    }
118}
119