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 */
27
28 public class ListenerList implements Serializable, Iterable<EventListener>
29 {
30 private static final long serialVersionUID = -1934227607974228213L;
31
32 private final CopyOnWriteArrayList<EventListener> __listeners;
33
34 public ListenerList()
35 {
36 __listeners = new CopyOnWriteArrayList<EventListener>();
37 }
38
39 public void addListener(EventListener listener)
40 {
41 __listeners.add(listener);
42 }
43
44 public void removeListener(EventListener listener)
45 {
46 __listeners.remove(listener);
47 }
48
49 public int getListenerCount()
50 {
51 return __listeners.size();
52 }
53
54 /**
55 * Return an {@link Iterator} for the {@link EventListener} instances.
56 *
57 * @return an {@link Iterator} for the {@link EventListener} instances
58 * @since 2.0
59 * TODO Check that this is a good defensive strategy
60 */
61 @Override
62 public Iterator<EventListener> iterator() {
63 return __listeners.iterator();
64 }
65
66 }