1 /*
2  *  Licensed to the Apache Software Foundation (ASF) under one or more
3  *  contributor license agreements.  See the NOTICE file distributed with
4  *  this work for additional information regarding copyright ownership.
5  *  The ASF licenses this file to You under the Apache License, Version 2.0
6  *  (the "License"); you may not use this file except in compliance with
7  *  the License.  You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *  Unless required by applicable law or agreed to in writing, software
12  *  distributed under the License is distributed on an "AS IS" BASIS,
13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *  See the License for the specific language governing permissions and
15  *  limitations under the License.
16  */
17 
18 package java.security;
19 
20 /**
21  * Represents the Service Provider Interface (SPI) for java.security.Policy
22  * class.
23  *
24  * <p>If there is any class that wants to provide a Policy implementation, all
25  * abstract methods in this SPI should be implemented.
26  *
27  * <p>The detailed implementations should offer a public constructor, in which a
28  * Policy.Paramters implementation acts as an input parameter.If the
29  * Policy.Paramters input cannot by understood by the constructor, an
30  * IllegalArgumentException will be thrown.
31  */
32 public abstract class PolicySpi {
33 
PolicySpi()34     public PolicySpi() {
35         // default constructor
36     }
37 
38     /**
39      * Answers if the policy has granted a Permission to a
40      * ProtectionDomain.
41      *
42      * @param domain -
43      *            the domain to check.
44      * @param permission -
45      *            check whether this permission is granted to the specified
46      *            domain.
47      * @return - true if the permission is granted to the domain.
48      *
49      */
engineImplies(ProtectionDomain domain, Permission permission)50     protected abstract boolean engineImplies(ProtectionDomain domain,
51             Permission permission);
52 
53     /**
54      * Refreshes/reloads the policy configuration. The behavior of this method
55      * depends on the implementation. For example, calling refresh on a
56      * file-based policy will cause the file to be re-read.
57      *
58      * The default implementation of this method does nothing. This method
59      * should be overridden if a refresh operation is supported by the policy
60      * implementation.
61      *
62      */
engineRefresh()63     protected void engineRefresh() {
64         // do nothing in default implementation
65     }
66 
67     /**
68      * Answers a PermissionCollection object containing the set of permissions
69      * granted to the specified CodeSource.
70      *
71      * The default implementation of this method returns
72      * Policy.UNSUPPORTED_EMPTY_COLLECTION object. This method can be overridden
73      * if the policy implementation can return a set of permissions granted to a
74      * CodeSource.
75      *
76      * @param codesource -
77      *            the CodeSource to which the returned PermissionCollection has
78      *            been granted.
79      * @return a set of permissions granted to the specified CodeSource. If this
80      *         operation is supported, the returned set of permissions must be a
81      *         new mutable instance and it must support heterogeneous Permission
82      *         types. If this operation is not supported,
83      *         Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
84      */
engineGetPermissions(CodeSource codesource)85     protected PermissionCollection engineGetPermissions(CodeSource codesource) {
86         return Policy.UNSUPPORTED_EMPTY_COLLECTION;
87     }
88 
89     /**
90      * Answers a PermissionCollection object containing the set of permissions
91      * granted to the specified ProtectionDomain.
92      *
93      * The default implementation of this method returns
94      * Policy.UNSUPPORTED_EMPTY_COLLECTION object. This method can be overridden
95      * if the policy implementation can return a set of permissions granted to a
96      * ProtectionDomain.
97      *
98      * @param domain -
99      *            the ProtectionDomain to which the returned
100      *            PermissionCollection has been granted.
101      * @return a set of permissions granted to the specified ProtectionDomain.
102      *         If this operation is supported, the returned set of permissions
103      *         must be a new mutable instance and it must support heterogeneous
104      *         Permission types. If this operation is not supported,
105      *         Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
106      */
engineGetPermissions(ProtectionDomain domain)107     protected PermissionCollection engineGetPermissions(ProtectionDomain domain) {
108         return Policy.UNSUPPORTED_EMPTY_COLLECTION;
109     }
110 }
111