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 018package org.apache.commons.net.io; 019 020import java.util.EventListener; 021 022import org.apache.commons.net.util.ListenerList; 023 024/** 025 * The CopyStreamAdapter will relay CopyStreamEvents to a list of listeners 026 * when either of its bytesTransferred() methods are called. Its purpose 027 * is to facilitate the notification of the progress of a copy operation 028 * performed by one of the static copyStream() methods in 029 * org.apache.commons.io.Util to multiple listeners. The static 030 * copyStream() methods invoke the 031 * bytesTransfered(long, int) of a CopyStreamListener for performance 032 * reasons and also because multiple listeners cannot be registered given 033 * that the methods are static. 034 * 035 * 036 * @see CopyStreamEvent 037 * @see CopyStreamListener 038 * @see Util 039 */ 040public class CopyStreamAdapter implements CopyStreamListener 041{ 042 private final ListenerList internalListeners; 043 044 /** 045 * Creates a new copyStreamAdapter. 046 */ 047 public CopyStreamAdapter() 048 { 049 internalListeners = new ListenerList(); 050 } 051 052 /** 053 * This method is invoked by a CopyStreamEvent source after copying 054 * a block of bytes from a stream. The CopyStreamEvent will contain 055 * the total number of bytes transferred so far and the number of bytes 056 * transferred in the last write. The CopyStreamAdapater will relay 057 * the event to all of its registered listeners, listing itself as the 058 * source of the event. 059 * @param event The CopyStreamEvent fired by the copying of a block of 060 * bytes. 061 */ 062 @Override 063 public void bytesTransferred(final CopyStreamEvent event) 064 { 065 for (final EventListener listener : internalListeners) 066 { 067 ((CopyStreamListener) listener).bytesTransferred(event); 068 } 069 } 070 071 /** 072 * This method is not part of the JavaBeans model and is used by the 073 * static methods in the org.apache.commons.io.Util class for efficiency. 074 * It is invoked after a block of bytes to inform the listener of the 075 * transfer. The CopyStreamAdapater will create a CopyStreamEvent 076 * from the arguments and relay the event to all of its registered 077 * listeners, listing itself as the source of the event. 078 * @param totalBytesTransferred The total number of bytes transferred 079 * so far by the copy operation. 080 * @param bytesTransferred The number of bytes copied by the most recent 081 * write. 082 * @param streamSize The number of bytes in the stream being copied. 083 * This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if 084 * the size is unknown. 085 */ 086 @Override 087 public void bytesTransferred(final long totalBytesTransferred, 088 final int bytesTransferred, final long streamSize) 089 { 090 for (final EventListener listener : internalListeners) 091 { 092 ((CopyStreamListener) listener).bytesTransferred( 093 totalBytesTransferred, bytesTransferred, streamSize); 094 } 095 } 096 097 /** 098 * Registers a CopyStreamListener to receive CopyStreamEvents. 099 * Although this method is not declared to be synchronized, it is 100 * implemented in a thread safe manner. 101 * @param listener The CopyStreamlistener to register. 102 */ 103 public void addCopyStreamListener(final CopyStreamListener listener) 104 { 105 internalListeners.addListener(listener); 106 } 107 108 /** 109 * Unregisters a CopyStreamListener. Although this method is not 110 * synchronized, it is implemented in a thread safe manner. 111 * @param listener The CopyStreamlistener to unregister. 112 */ 113 public void removeCopyStreamListener(final CopyStreamListener listener) 114 { 115 internalListeners.removeListener(listener); 116 } 117}