1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.cache;
18
19import com.google.common.annotations.Beta;
20
21import java.util.concurrent.Executor;
22
23/**
24 * A collection of common removal listeners.
25 *
26 * @author Charles Fry
27 * @since 10.0
28 */
29@Beta
30public final class RemovalListeners {
31
32  private RemovalListeners() {}
33
34  /**
35   * Returns a {@code RemovalListener} which processes all eviction
36   * notifications using {@code executor}.
37   *
38   * @param listener the backing listener
39   * @param executor the executor with which removal notifications are
40   *     asynchronously executed
41   */
42  public static <K, V> RemovalListener<K, V> asynchronous(
43      final RemovalListener<K, V> listener, final Executor executor) {
44    return new RemovalListener<K, V>() {
45      @Override
46      public void onRemoval(final RemovalNotification<K, V> notification) {
47        executor.execute(new Runnable() {
48          @Override
49          public void run() {
50            listener.onRemoval(notification);
51          }
52        });
53      }
54    };
55  }
56
57}
58