ResourceSet


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  
19  package org.apache.catalina.util;
20  
21  
22  import java.util.Collection  ;
23  import java.util.HashSet  ;
24  
25  
26  /**
27   * Extended implementation of <strong>HashSet</strong> that includes a
28   * <code>locked</code> property.  This class can be used to safely expose
29   * resource path sets to user classes without having to clone them in order
30   * to avoid modifications.  When first created, a <code>ResourceMap</code>
31   * is not locked.
32   *
33   * @author Craig R. McClanahan
34   * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
35   */
36  
37  public final class ResourceSet extends HashSet   {
38  
39  
40      // ----------------------------------------------------------- Constructors
41  
42  
43      /**
44       * Construct a new, empty set with the default initial capacity and
45       * load factor.
46       */
47      public ResourceSet() {
48  
49          super();
50  
51      }
52  
53  
54      /**
55       * Construct a new, empty set with the specified initial capacity and
56       * default load factor.
57       *
58       * @param initialCapacity The initial capacity of this set
59       */
60      public ResourceSet(int initialCapacity) {
61  
62          super(initialCapacity);
63  
64      }
65  
66  
67      /**
68       * Construct a new, empty set with the specified initial capacity and
69       * load factor.
70       *
71       * @param initialCapacity The initial capacity of this set
72       * @param loadFactor The load factor of this set
73       */
74      public ResourceSet(int initialCapacity, float loadFactor) {
75  
76          super(initialCapacity, loadFactor);
77  
78      }
79  
80  
81      /**
82       * Construct a new set with the same contents as the existing collection.
83       *
84       * @param coll The collection whose contents we should copy
85       */
86      public ResourceSet(Collection   coll) {
87  
88          super(coll);
89  
90      }
91  
92  
93      // ------------------------------------------------------------- Properties
94  
95  
96      /**
97       * The current lock state of this parameter map.
98       */
99      private boolean locked = false;
100 
101 
102     /**
103      * Return the locked state of this parameter map.
104      */
105     public boolean isLocked() {
106 
107         return (this.locked);
108 
109     }
110 
111 
112     /**
113      * Set the locked state of this parameter map.
114      *
115      * @param locked The new locked state
116      */
117     public void setLocked(boolean locked) {
118 
119         this.locked = locked;
120 
121     }
122 
123 
124     /**
125      * The string manager for this package.
126      */
127     private static final StringManager sm =
128         StringManager.getManager("org.apache.catalina.util");
129 
130 
131     // --------------------------------------------------------- Public Methods
132 
133 
134     /**
135      * Add the specified element to this set if it is not already present.
136      * Return <code>true</code> if the element was added.
137      *
138      * @param o The object to be added
139      *
140      * @exception IllegalStateException if this ResourceSet is locked
141      */
142     public boolean add(Object   o) {
143 
144         if (locked)
145             throw new IllegalStateException  
146               (sm.getString("resourceSet.locked"));
147         return (super.add(o));
148 
149     }
150 
151 
152     /**
153      * Remove all of the elements from this set.
154      *
155      * @exception IllegalStateException if this ResourceSet is locked
156      */
157     public void clear() {
158 
159         if (locked)
160             throw new IllegalStateException  
161               (sm.getString("resourceSet.locked"));
162         super.clear();
163 
164     }
165 
166 
167     /**
168      * Remove the given element from this set if it is present.
169      * Return <code>true</code> if the element was removed.
170      *
171      * @param o The object to be removed
172      *
173      * @exception IllegalStateException if this ResourceSet is locked
174      */
175     public boolean remove(Object   o) {
176 
177         if (locked)
178             throw new IllegalStateException  
179               (sm.getString("resourceSet.locked"));
180         return (super.remove(o));
181 
182     }
183 
184 
185 }
186
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