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.io; 019 020 import java.util.EventListener; 021 022 /** 023 * The CopyStreamListener class can accept CopyStreamEvents to keep track 024 * of the progress of a stream copying operation. However, it is currently 025 * not used that way within NetComponents for performance reasons. Rather 026 * the bytesTransferred(long, int) method is called directly rather than 027 * passing an event to bytesTransferred(CopyStreamEvent), saving the creation 028 * of a CopyStreamEvent instance. Also, the only place where 029 * CopyStreamListener is currently used within NetComponents is in the 030 * static methods of the uninstantiable org.apache.commons.io.Util class, which 031 * would preclude the use of addCopyStreamListener and 032 * removeCopyStreamListener methods. However, future additions may use the 033 * JavaBean event model, which is why the hooks have been included from the 034 * beginning. 035 * <p> 036 * <p> 037 * @see CopyStreamEvent 038 * @see CopyStreamAdapter 039 * @see Util 040 * @author <a href="mailto:savarese@apache.org">Daniel F. Savarese</a> 041 * @version $Id: CopyStreamListener.java 489397 2006-12-21 16:28:51Z rwinston $ 042 */ 043 public interface CopyStreamListener extends EventListener 044 { 045 /** 046 * This method is invoked by a CopyStreamEvent source after copying 047 * a block of bytes from a stream. The CopyStreamEvent will contain 048 * the total number of bytes transferred so far and the number of bytes 049 * transferred in the last write. 050 * @param event The CopyStreamEvent fired by the copying of a block of 051 * bytes. 052 */ 053 public void bytesTransferred(CopyStreamEvent event); 054 055 056 /** 057 * This method is not part of the JavaBeans model and is used by the 058 * static methods in the org.apache.commons.io.Util class for efficiency. 059 * It is invoked after a block of bytes to inform the listener of the 060 * transfer. 061 * @param totalBytesTransferred The total number of bytes transferred 062 * so far by the copy operation. 063 * @param bytesTransferred The number of bytes copied by the most recent 064 * write. 065 * @param streamSize The number of bytes in the stream being copied. 066 * This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if 067 * the size is unknown. 068 */ 069 public void bytesTransferred(long totalBytesTransferred, 070 int bytesTransferred, 071 long streamSize); 072 }