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 * https://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 package org.apache.commons.net.io;
18
19 import java.util.EventListener;
20
21 /**
22 * Accepts {@link CopyStreamEvent}s to track the progress of a stream copying operation. However, it is currently not used that way within Net for performance
23 * reasons. Rather, the bytesTransferred(long, int) method is called directly rather than passing an event to bytesTransferred(CopyStreamEvent), saving the
24 * creation of a CopyStreamEvent instance. Also, the only place where CopyStreamListener is currently used within Net is in the static methods of the
25 * uninstantiable org.apache.commons.io.Util class, which would preclude the use of addCopyStreamListener and removeCopyStreamListener methods. However, future
26 * additions may use the JavaBean event model, which is why the hooks have been included from the beginning.
27 *
28 * @see CopyStreamEvent
29 * @see CopyStreamAdapter
30 * @see Util
31 */
32 public interface CopyStreamListener extends EventListener {
33 /**
34 * Accepts a source event after copying a block of bytes from a stream. The CopyStreamEvent will contain the total number of bytes transferred so far and
35 * the number of bytes transferred in the last write.
36 *
37 * @param event The CopyStreamEvent fired by the copying of a block of bytes.
38 */
39 void bytesTransferred(CopyStreamEvent event);
40
41 /**
42 * This method is not part of the JavaBeans model and is used by the static methods in the org.apache.commons.io.Util class for efficiency. It is invoked
43 * after a block of bytes to inform the listener of the transfer.
44 *
45 * @param totalBytesTransferred The total number of bytes transferred so far by the copy operation.
46 * @param bytesTransferred The number of bytes copied by the most recent write.
47 * @param streamSize The number of bytes in the stream being copied. This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if the size is
48 * unknown.
49 */
50 void bytesTransferred(long totalBytesTransferred, int bytesTransferred, long streamSize);
51 }