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 * https://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 package org.apache.commons.net; 18 19 import java.io.ObjectInputStream; 20 import java.io.ObjectOutputStream; 21 import java.io.Serializable; 22 23 import org.apache.commons.net.util.ListenerList; 24 25 /** 26 * ProtocolCommandSupport is a convenience class for managing a list of ProtocolCommandListeners and firing ProtocolCommandEvents. You can simply delegate 27 * ProtocolCommandEvent firing and listener registering/unregistering tasks to this class. 28 * 29 * @see ProtocolCommandEvent 30 * @see ProtocolCommandListener 31 */ 32 public class ProtocolCommandSupport implements Serializable { 33 34 /** 35 * Serialization is unnecessary for this class. Reject attempts to do so until such time as the Serializable attribute can be dropped. 36 */ 37 private static final long serialVersionUID = -8017692739988399978L; 38 39 /** 40 * The source to use for all generated ProtocolCommandEvents. 41 */ 42 private final Object source; 43 44 /** 45 * The ProtocolCommandListener. 46 */ 47 private final ListenerList<ProtocolCommandListener> listeners; 48 49 /** 50 * Creates a ProtocolCommandSupport instance using the indicated source as the source of ProtocolCommandEvents. 51 * 52 * @param source The source to use for all generated ProtocolCommandEvents. 53 */ 54 public ProtocolCommandSupport(final Object source) { 55 this.listeners = new ListenerList<>(); 56 this.source = source; 57 } 58 59 /** 60 * Adds a ProtocolCommandListener. 61 * 62 * @param listener The ProtocolCommandListener to add. 63 */ 64 public void addProtocolCommandListener(final ProtocolCommandListener listener) { 65 listeners.addListener(listener); 66 } 67 68 /** 69 * Fires a ProtocolCommandEvent signaling the sending of a command to all registered listeners, invoking their 70 * {@link org.apache.commons.net.ProtocolCommandListener#protocolCommandSent protocolCommandSent()} methods. 71 * 72 * @param command The string representation of the command type sent, not including the arguments (e.g., "STAT" or "GET"). 73 * @param message The entire command string verbatim as sent to the server, including all arguments. 74 */ 75 public void fireCommandSent(final String command, final String message) { 76 if (!listeners.isEmpty()) { 77 final ProtocolCommandEvent event = new ProtocolCommandEvent(source, command, message); 78 listeners.forEach(listener -> listener.protocolCommandSent(event)); 79 } 80 } 81 82 /** 83 * Fires a ProtocolCommandEvent signaling the reception of a command reply to all registered listeners, invoking their 84 * {@link org.apache.commons.net.ProtocolCommandListener#protocolReplyReceived protocolReplyReceived()} methods. 85 * 86 * @param replyCode The integer code indicating the nature of the reply. This will be the protocol integer value for protocols that use integer reply codes, 87 * or the reply class constant corresponding to the reply for protocols like POP3 that use strings like OK rather than integer codes (i.e., 88 * POP3Repy.OK). 89 * @param message The entire reply as received from the server. 90 */ 91 public void fireReplyReceived(final int replyCode, final String message) { 92 if (!listeners.isEmpty()) { 93 final ProtocolCommandEvent event = new ProtocolCommandEvent(source, replyCode, message); 94 listeners.forEach(listener -> listener.protocolReplyReceived(event)); 95 } 96 } 97 98 /** 99 * Gets the number of ProtocolCommandListeners currently registered. 100 * 101 * @return The number of ProtocolCommandListeners currently registered. 102 */ 103 public int getListenerCount() { 104 return listeners.getListenerCount(); 105 } 106 107 /** 108 * Throws UnsupportedOperationException. 109 * 110 * @param ignored Ignored. 111 */ 112 private void readObject(final ObjectInputStream ignored) { 113 throw new UnsupportedOperationException("Serialization is not supported"); 114 } 115 116 /** 117 * Removes a ProtocolCommandListener. 118 * 119 * @param listener The ProtocolCommandListener to remove. 120 */ 121 public void removeProtocolCommandListener(final ProtocolCommandListener listener) { 122 listeners.removeListener(listener); 123 } 124 125 /** 126 * Always throws {@link UnsupportedOperationException}. 127 * 128 * @param ignored ignored. 129 * @throws UnsupportedOperationException Always thrown. 130 */ 131 private void writeObject(final ObjectOutputStream ignored) { 132 throw new UnsupportedOperationException("Serialization is not supported"); 133 } 134 }