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
18package java.security;
19
20import java.util.Enumeration;
21import java.util.Hashtable;
22
23/**
24 * A default {@code PermissionCollection} implementation that uses a hashtable.
25 * Each hashtable entry stores a Permission object as both the key and the
26 * value.
27 * <p>
28 * This {@code PermissionCollection} is intended for storing &quot;neutral&quot;
29 * permissions which do not require special collection.
30 */
31
32final class PermissionsHash extends PermissionCollection {
33
34    private static final long serialVersionUID = -8491988220802933440L;
35
36    private final Hashtable perms = new Hashtable();
37
38    /**
39     * Adds the argument to the collection.
40     *
41     * @param permission
42     *            the permission to add to the collection.
43     */
44    public void add(Permission permission) {
45        perms.put(permission, permission);
46    }
47
48    /**
49     * Returns an enumeration of the permissions in the receiver.
50     *
51     * @return Enumeration the permissions in the receiver.
52     */
53    public Enumeration elements() {
54        return perms.elements();
55    }
56
57    /**
58     * Indicates whether the argument permission is implied by the permissions
59     * contained in the receiver.
60     *
61     * @return boolean <code>true</code> if the argument permission is implied
62     *         by the permissions in the receiver, and <code>false</code> if
63     *         it is not.
64     * @param permission
65     *            java.security.Permission the permission to check
66     */
67    public boolean implies(Permission permission) {
68        for (Enumeration elements = elements(); elements.hasMoreElements();) {
69            if (((Permission)elements.nextElement()).implies(permission)) {
70                return true;
71            }
72        }
73        return false;
74    }
75}
76