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 * http://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
18 package org.apache.commons.net.io;
19
20 import java.util.EventListener;
21
22 /**
23 * The CopyStreamListener class can accept CopyStreamEvents to keep track
24 * of the progress of a stream copying operation. However, it is currently
25 * not used that way within NetComponents for performance reasons. Rather
26 * the bytesTransferred(long, int) method is called directly rather than
27 * passing an event to bytesTransferred(CopyStreamEvent), saving the creation
28 * of a CopyStreamEvent instance. Also, the only place where
29 * CopyStreamListener is currently used within NetComponents is in the
30 * static methods of the uninstantiable org.apache.commons.io.Util class, which
31 * would preclude the use of addCopyStreamListener and
32 * removeCopyStreamListener methods. However, future additions may use the
33 * JavaBean event model, which is why the hooks have been included from the
34 * beginning.
35 * <p>
36 * <p>
37 * @see CopyStreamEvent
38 * @see CopyStreamAdapter
39 * @see Util
40 * @version $Id: CopyStreamListener.java 1299238 2012-03-10 17:12:28Z sebb $
41 */
42 public interface CopyStreamListener extends EventListener
43 {
44 /**
45 * This method is invoked by a CopyStreamEvent source after copying
46 * a block of bytes from a stream. The CopyStreamEvent will contain
47 * the total number of bytes transferred so far and the number of bytes
48 * transferred in the last write.
49 * @param event The CopyStreamEvent fired by the copying of a block of
50 * bytes.
51 */
52 public void bytesTransferred(CopyStreamEvent event);
53
54
55 /**
56 * This method is not part of the JavaBeans model and is used by the
57 * static methods in the org.apache.commons.io.Util class for efficiency.
58 * It is invoked after a block of bytes to inform the listener of the
59 * transfer.
60 * @param totalBytesTransferred The total number of bytes transferred
61 * so far by the copy operation.
62 * @param bytesTransferred The number of bytes copied by the most recent
63 * write.
64 * @param streamSize The number of bytes in the stream being copied.
65 * This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if
66 * the size is unknown.
67 */
68 public void bytesTransferred(long totalBytesTransferred,
69 int bytesTransferred,
70 long streamSize);
71 }