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;
019    import java.util.EventListener;
020    
021    /***
022     * There exists a large class of IETF protocols that work by sending an
023     * ASCII text command and arguments to a server, and then receiving an
024     * ASCII text reply.  For debugging and other purposes, it is extremely
025     * useful to log or keep track of the contents of the protocol messages.
026     * The ProtocolCommandListener interface coupled with the
027     * {@link ProtocolCommandEvent} class facilitate this process.
028     * <p>
029     * To receive ProtocolCommandEvents, you merely implement the
030     * ProtocolCommandListener interface and register the class as a listener
031     * with a ProtocolCommandEvent source such as
032     * {@link org.apache.commons.net.ftp.FTPClient}.
033     * <p>
034     * <p>
035     * @see ProtocolCommandEvent
036     * @see ProtocolCommandSupport
037     ***/
038    
039    public interface ProtocolCommandListener extends EventListener
040    {
041    
042        /***
043         * This method is invoked by a ProtocolCommandEvent source after
044         * sending a protocol command to a server.
045         * <p>
046         * @param event The ProtocolCommandEvent fired.
047         ***/
048        public void protocolCommandSent(ProtocolCommandEvent event);
049    
050        /***
051         * This method is invoked by a ProtocolCommandEvent source after
052         * receiving a reply from a server.
053         * <p>
054         * @param event The ProtocolCommandEvent fired.
055         ***/
056        public void protocolReplyReceived(ProtocolCommandEvent event);
057    
058    }