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 * https://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 import java.util.Map.Entry;
21
22 import org.apache.commons.collections4.KeyValue;
23 import org.apache.commons.collections4.Unmodifiable;
24
25 /**
26 * A {@link Entry Map.Entry} that throws
27 * UnsupportedOperationException when {@code setValue} is called.
28 *
29 * @param <K> The type of keys
30 * @param <V> The type of mapped values
31 * @since 3.0
32 */
33 public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> implements Unmodifiable {
34
35 /**
36 * Constructs a new entry with the specified key and given value.
37 *
38 * @param key The key for the entry, may be null
39 * @param value The value for the entry, may be null
40 */
41 public UnmodifiableMapEntry(final K key, final V value) {
42 super(key, value);
43 }
44
45 /**
46 * Constructs a new entry from the specified {@code KeyValue}.
47 *
48 * @param pair The pair to copy, must not be null
49 * @throws NullPointerException if the entry is null
50 */
51 public UnmodifiableMapEntry(final KeyValue<? extends K, ? extends V> pair) {
52 super(pair.getKey(), pair.getValue());
53 }
54
55 /**
56 * Constructs a new entry from the specified {@code Map.Entry}.
57 *
58 * @param entry The entry to copy, must not be null
59 * @throws NullPointerException if the entry is null
60 */
61 public UnmodifiableMapEntry(final Map.Entry<? extends K, ? extends V> entry) {
62 super(entry.getKey(), entry.getValue());
63 }
64
65 /**
66 * Throws UnsupportedOperationException.
67 *
68 * @param value The new value
69 * @return The previous value
70 * @throws UnsupportedOperationException always
71 */
72 @Override
73 public V setValue(final V value) {
74 throw new UnsupportedOperationException("setValue() is not supported");
75 }
76
77 }