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 }