1 /**
2 * Copyright 2010 The Kuali Foundation Licensed under the
3 * Educational Community License, Version 2.0 (the "License"); you may
4 * not use this file except in compliance with the License. You may
5 * obtain a copy of the License at
6 *
7 * http://www.osedu.org/licenses/ECL-2.0
8 *
9 * Unless required by applicable law or agreed to in writing,
10 * software distributed under the License is distributed on an "AS IS"
11 * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
12 * or implied. See the License for the specific language governing
13 * permissions and limitations under the License.
14 */
15
16 package org.kuali.student.common.util;
17
18 import java.util.LinkedHashMap;
19 import java.util.Map;
20
21 /**
22 * A <code>Map<code> implementation with a fixed maximum size of a
23 * least recently used (LRU) entry list using a <code>LinkedHashMap</code>.
24 *
25 * @param <K> Key
26 * @param <V> Value
27 */
28 public class LRUMap<K,V> extends LinkedHashMap<K,V> {
29 /** Class serial version uid */
30 private static final long serialVersionUID = 1L;
31
32 /** Maximum size of map */
33 private int maxSize = 50;
34
35 /**
36 * Constructs a new LRU Map with a default maximum size of 50 entries.
37 */
38 public LRUMap() {
39 }
40
41 /**
42 * Constructs a new LRU Map.
43 *
44 * @param maxSize Maximum size of LRU map.
45 */
46 public LRUMap(int maxSize) {
47 this.maxSize = maxSize;
48 }
49
50 /**
51 * Removed oldest entry in map.
52 *
53 * @param eldest Oldest entry to remove
54 */
55 public boolean removeEldestEntry(Map.Entry<K,V> eldest) {
56 return size() > this.maxSize;
57 }
58 }