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
18 package org.apache.commons.net.examples.util;
19
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.io.OutputStream;
23
24 import org.apache.commons.io.IOUtils;
25 import org.apache.commons.net.util.NetConstants;
26
27 /**
28 * This is a utility class providing a reader/writer capability required by the weatherTelnet, rexec, rshell, and rlogin example programs. The only point of the
29 * class is to hold the static method readWrite which spawns a reader thread and a writer thread. The reader thread reads from a local input source (presumably
30 * stdin) and writes the data to a remote output destination. The writer thread reads from a remote input source and writes to a local output destination. The
31 * threads terminate when the remote input source closes.
32 */
33 public final class IOUtil {
34
35 public static void readWrite(final InputStream remoteInput, final OutputStream remoteOutput, final InputStream localInput, final OutputStream localOutput) {
36 final Thread readerThread;
37 final Thread writerThread;
38 readerThread = new Thread(() -> {
39 int ch;
40 try {
41 while (!Thread.interrupted() && (ch = localInput.read()) != NetConstants.EOS) {
42 remoteOutput.write(ch);
43 remoteOutput.flush();
44 }
45 } catch (final IOException e) {
46 // e.printStackTrace();
47 }
48 });
49 writerThread = new Thread(() -> {
50 try {
51 IOUtils.copyLarge(remoteInput, localOutput);
52 } catch (final IOException e) {
53 e.printStackTrace();
54 System.exit(1);
55 }
56 });
57 writerThread.setPriority(Thread.currentThread().getPriority() + 1);
58 writerThread.start();
59 readerThread.setDaemon(true);
60 readerThread.start();
61 try {
62 writerThread.join();
63 readerThread.interrupt();
64 } catch (final InterruptedException e) {
65 Thread.currentThread().interrupt();
66 }
67 }
68 }