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 package org.apache.myfaces.shared.util;
20
21 import java.util.LinkedHashMap;
22 import java.util.Map;
23
24 public class LRULinkedHashMap<K,V> extends LinkedHashMap<K,V>
25 {
26 private static final float DEFAULT_LOAD_FACTOR = 0.75f;
27 private final int capacity;
28
29 public LRULinkedHashMap(int capacity)
30 {
31 // 1 extra element as add happens before remove (101), and load factor big
32 // enough to avoid triggering resize. True = keep in access order.
33 super(capacity + 1, DEFAULT_LOAD_FACTOR, true);
34 this.capacity = capacity;
35 }
36
37 @Override
38 protected boolean removeEldestEntry(Map.Entry<K,V> eldest)
39 {
40 return size() > capacity;
41 }
42 }