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 org.apache.commons.collections.KeyValue;
20
21 /**
22 * Abstract pair class to assist with creating <code>KeyValue</code>
23 * and {@link java.util.Map.Entry Map.Entry} implementations.
24 *
25 * @since 3.0
26 * @version $Id: AbstractKeyValue.java 1429905 2013-01-07 17:15:14Z ggregory $
27 */
28 public abstract class AbstractKeyValue<K, V> implements KeyValue<K, V> {
29
30 /** The key */
31 protected K key;
32 /** The value */
33 protected V value;
34
35 /**
36 * Constructs a new pair 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 protected AbstractKeyValue(final K key, final V value) {
42 super();
43 this.key = key;
44 this.value = value;
45 }
46
47 /**
48 * Gets the key from the pair.
49 *
50 * @return the key
51 */
52 public K getKey() {
53 return key;
54 }
55
56 /**
57 * Gets the value from the pair.
58 *
59 * @return the value
60 */
61 public V getValue() {
62 return value;
63 }
64
65 /**
66 * Gets a debugging String view of the pair.
67 *
68 * @return a String view of the entry
69 */
70 @Override
71 public String toString() {
72 return new StringBuilder()
73 .append(getKey())
74 .append('=')
75 .append(getValue())
76 .toString();
77 }
78
79 }