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; 021 022/** 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 * 036 * 037 * @see CopyStreamEvent 038 * @see CopyStreamAdapter 039 * @see Util 040 */ 041public interface CopyStreamListener extends EventListener 042{ 043 /** 044 * This method is invoked by a CopyStreamEvent source after copying 045 * a block of bytes from a stream. The CopyStreamEvent will contain 046 * the total number of bytes transferred so far and the number of bytes 047 * transferred in the last write. 048 * @param event The CopyStreamEvent fired by the copying of a block of 049 * bytes. 050 */ 051 void bytesTransferred(CopyStreamEvent event); 052 053 054 /** 055 * This method is not part of the JavaBeans model and is used by the 056 * static methods in the org.apache.commons.io.Util class for efficiency. 057 * It is invoked after a block of bytes to inform the listener of the 058 * transfer. 059 * @param totalBytesTransferred The total number of bytes transferred 060 * so far by the copy operation. 061 * @param bytesTransferred The number of bytes copied by the most recent 062 * write. 063 * @param streamSize The number of bytes in the stream being copied. 064 * This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if 065 * the size is unknown. 066 */ 067 void bytesTransferred(long totalBytesTransferred, 068 int bytesTransferred, 069 long streamSize); 070}