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 }