001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.net.util;
019
020 import java.io.Serializable;
021 import java.util.EventListener;
022 import java.util.Iterator;
023 import java.util.concurrent.CopyOnWriteArrayList;
024
025 /**
026 * @author Daniel F. Savarese
027 */
028
029 public class ListenerList implements Serializable, Iterable<EventListener>
030 {
031 private final CopyOnWriteArrayList<EventListener> __listeners;
032
033 public ListenerList()
034 {
035 __listeners = new CopyOnWriteArrayList<EventListener>();
036 }
037
038 public void addListener(EventListener listener)
039 {
040 __listeners.add(listener);
041 }
042
043 public void removeListener(EventListener listener)
044 {
045 __listeners.remove(listener);
046 }
047
048 public int getListenerCount()
049 {
050 return __listeners.size();
051 }
052
053 /**
054 * Return an {@link Iterator} for the {@link EventListener} instances
055 *
056 * @since 2.0
057 * TODO Check that this is a good defensive strategy
058 */
059 public Iterator<EventListener> iterator() {
060 return __listeners.iterator();
061 }
062
063 }