001    /*
002     * Copyright 2001-2005 The Apache Software Foundation
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *     http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.apache.commons.net.util;
017    
018    import java.io.Serializable;
019    import java.util.Enumeration;
020    import java.util.EventListener;
021    import java.util.Vector;
022    
023    /**
024     * @author Daniel F. Savarese
025     */
026    
027    public class ListenerList implements Serializable
028    {
029        private Vector __listeners;
030    
031        public ListenerList()
032        {
033            __listeners = new Vector();
034        }
035    
036        public synchronized void addListener(EventListener listener)
037        {
038            __listeners.addElement(listener);
039        }
040    
041        public synchronized void removeListener(EventListener listener)
042        {
043            __listeners.removeElement(listener);
044        }
045    
046        public synchronized Enumeration getListeners()
047        {
048            return ((Vector)__listeners.clone()).elements();
049        }
050    
051        public int getListenerCount()
052        {
053            return __listeners.size();
054        }
055    
056    }