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 }