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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  package org.apache.commons.collections.keyvalue;
18  
19  import java.util.Map;
20  
21  import org.apache.commons.collections.KeyValue;
22  import org.apache.commons.collections.Unmodifiable;
23  
24  /**
25   * A {@link java.util.Map.Entry Map.Entry} that throws
26   * UnsupportedOperationException when <code>setValue</code> is called.
27   *
28   * @since 3.0
29   * @version $Id: UnmodifiableMapEntry.java 1429905 2013-01-07 17:15:14Z ggregory $
30   */
31  public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> implements Unmodifiable {
32  
33      /**
34       * Constructs a new entry with the specified key and given value.
35       *
36       * @param key  the key for the entry, may be null
37       * @param value  the value for the entry, may be null
38       */
39      public UnmodifiableMapEntry(final K key, final V value) {
40          super(key, value);
41      }
42  
43      /**
44       * Constructs a new entry from the specified <code>KeyValue</code>.
45       *
46       * @param pair  the pair to copy, must not be null
47       * @throws NullPointerException if the entry is null
48       */
49      public UnmodifiableMapEntry(final KeyValue<K, V> pair) {
50          super(pair.getKey(), pair.getValue());
51      }
52  
53      /**
54       * Constructs a new entry from the specified <code>Map.Entry</code>.
55       *
56       * @param entry  the entry to copy, must not be null
57       * @throws NullPointerException if the entry is null
58       */
59      public UnmodifiableMapEntry(final Map.Entry<K, V> entry) {
60          super(entry.getKey(), entry.getValue());
61      }
62  
63      /**
64       * Throws UnsupportedOperationException.
65       * 
66       * @param value  the new value
67       * @return the previous value
68       * @throws UnsupportedOperationException always
69       */
70      @Override
71      public V setValue(final V value) {
72          throw new UnsupportedOperationException("setValue() is not supported");
73      }
74  
75  }