1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.net.util;
19
20 import java.io.Serializable;
21 import java.util.EventListener;
22 import java.util.Iterator;
23 import java.util.concurrent.CopyOnWriteArrayList;
24
25 /**
26 * @author Daniel F. Savarese
27 */
28
29 public class ListenerList implements Serializable, Iterable<EventListener>
30 {
31 private final CopyOnWriteArrayList<EventListener> __listeners;
32
33 public ListenerList()
34 {
35 __listeners = new CopyOnWriteArrayList<EventListener>();
36 }
37
38 public void addListener(EventListener listener)
39 {
40 __listeners.add(listener);
41 }
42
43 public void removeListener(EventListener listener)
44 {
45 __listeners.remove(listener);
46 }
47
48 public int getListenerCount()
49 {
50 return __listeners.size();
51 }
52
53 /**
54 * Return an {@link Iterator} for the {@link EventListener} instances
55 *
56 * @since 2.0
57 * TODO Check that this is a good defensive strategy
58 */
59 public Iterator<EventListener> iterator() {
60 return __listeners.iterator();
61 }
62
63 }