1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.mavibot.btree;
21
22
23 import java.util.Comparator;
24
25
26 /**
27 * The Tuple class is used when we browse a btree, it will contain the results
28 * fetched from the btree.
29 *
30 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
31 *
32 * @param <K> The type for the Key
33 * @param <V> The type for the stored value
34 */
35 public class Tuple<K, V> implements Comparable<Tuple<K, V>>
36 {
37 /** The key */
38 protected K key;
39
40 /** The value */
41 protected V value;
42
43 /** The key comparator */
44 protected Comparator<K> keyComparator;
45
46
47 /**
48 * Creates a Tuple with no content
49 */
50 public Tuple()
51 {
52 }
53
54
55 /**
56 * Creates a Tuple containing a key and its associated value.
57 * @param key The key
58 * @param value The associated value
59 */
60 public Tuple( K key, V value )
61 {
62 this.key = key;
63 this.value = value;
64 }
65
66
67 /**
68 * Creates a Tuple containing a key and its associated value.
69 * @param key The key
70 * @param value The associated value
71 */
72 public Tuple( K key, V value, Comparator<K> keyComparator )
73 {
74 this.key = key;
75 this.value = value;
76 this.keyComparator = keyComparator;
77 }
78
79
80 /**
81 * @return the key
82 */
83 public K getKey()
84 {
85 return key;
86 }
87
88
89 /**
90 * @param key the key to set
91 */
92 public void setKey( K key )
93 {
94 this.key = key;
95 }
96
97
98 /**
99 * @return the value
100 */
101 public V getValue()
102 {
103 return value;
104 }
105
106
107 /**
108 * @param value the value to set
109 */
110 public void setValue( V value )
111 {
112 this.value = value;
113 }
114
115
116 /**
117 * @see Object#hashCode()
118 */
119 @Override
120 public int hashCode()
121 {
122 return key.hashCode();
123 }
124
125
126 /**
127 * @see Object#equals()
128 */
129 @SuppressWarnings("unchecked")
130 @Override
131 public boolean equals( Object obj )
132 {
133 if ( this == obj )
134 {
135 return true;
136 }
137
138 if ( !( obj instanceof Tuple ) )
139 {
140 return false;
141 }
142
143 if ( this.key == null )
144 {
145 return ( ( Tuple<K, V> ) obj ).key == null;
146 }
147
148 return this.key.equals( ( ( Tuple<K, V> ) obj ).key );
149 }
150
151
152 /**
153 * @see java.lang.Comparable#compareTo(java.lang.Object)
154 */
155 @Override
156 public int compareTo( Tuple<K, V> t )
157 {
158 if ( keyComparator != null )
159 {
160 return keyComparator.compare( key, t.key );
161 }
162 else
163 {
164 return 0;
165 }
166 }
167
168
169 /**
170 * @return the keyComparator
171 */
172 public Comparator<K> getKeyComparator()
173 {
174 return keyComparator;
175 }
176
177
178 /**
179 * @param keyComparator the keyComparator to set
180 */
181 public void setKeyComparator( Comparator<K> keyComparator )
182 {
183 this.keyComparator = keyComparator;
184 }
185
186
187 /**
188 * @see Object#toString()
189 */
190 public String toString()
191 {
192 return "<" + key + "," + value + ">";
193 }
194 }