1 package org.apache.directmemory.guava;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import com.google.common.cache.RemovalListener;
23 import com.google.common.cache.RemovalNotification;
24
25 /**
26 * Listener which forwards the notifications to a delegate. It is used to bridge the
27 * Guava Cache with DirectMemory CacheService
28 * @since 0.2
29 */
30 public class ForwardingListener<K, V>
31 implements RemovalListener<K, V>
32 {
33 private RemovalListener<K, V> delegate;
34
35 public ForwardingListener()
36 {
37 }
38
39 public ForwardingListener( RemovalListener<K, V> delegate )
40 {
41 this.delegate = delegate;
42 }
43
44 @Override
45 public void onRemoval( RemovalNotification<K, V> notification )
46 {
47 if ( delegate != null )
48 {
49 delegate.onRemoval( notification );
50 }
51 }
52
53 public void setDelegate( RemovalListener<K, V> delegate )
54 {
55 this.delegate = delegate;
56 }
57
58 public static <K, V> ForwardingListener<K, V> newInstance()
59 {
60 return new ForwardingListener<K, V>();
61 }
62
63 public static <K, V> ForwardingListener<K, V> newInstance( RemovalListener<K, V> delegate )
64 {
65 return new ForwardingListener<K, V>( delegate );
66 }
67 }