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.collections4.keyvalue;
18
19 import java.util.Map;
20
21 import org.apache.commons.collections4.KeyValue;
22 import org.apache.commons.collections4.Unmodifiable;
23
24 /**
25 * A {@link java.util.Map.Entry Map.Entry} that throws
26 * UnsupportedOperationException when {@code setValue} is called.
27 *
28 * @param <K> the type of keys
29 * @param <V> the type of mapped values
30 * @since 3.0
31 */
32 public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> implements Unmodifiable {
33
34 /**
35 * Constructs a new entry with the specified key and given value.
36 *
37 * @param key the key for the entry, may be null
38 * @param value the value for the entry, may be null
39 */
40 public UnmodifiableMapEntry(final K key, final V value) {
41 super(key, value);
42 }
43
44 /**
45 * Constructs a new entry from the specified {@code KeyValue}.
46 *
47 * @param pair the pair to copy, must not be null
48 * @throws NullPointerException if the entry is null
49 */
50 public UnmodifiableMapEntry(final KeyValue<? extends K, ? extends V> pair) {
51 super(pair.getKey(), pair.getValue());
52 }
53
54 /**
55 * Constructs a new entry from the specified {@code Map.Entry}.
56 *
57 * @param entry the entry to copy, must not be null
58 * @throws NullPointerException if the entry is null
59 */
60 public UnmodifiableMapEntry(final Map.Entry<? extends K, ? extends V> entry) {
61 super(entry.getKey(), entry.getValue());
62 }
63
64 /**
65 * Throws UnsupportedOperationException.
66 *
67 * @param value the new value
68 * @return the previous value
69 * @throws UnsupportedOperationException always
70 */
71 @Override
72 public V setValue(final V value) {
73 throw new UnsupportedOperationException("setValue() is not supported");
74 }
75
76 }