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 examples;
019
020import java.io.IOException;
021import java.io.InputStream;
022import java.io.OutputStream;
023import org.apache.commons.net.io.Util;
024
025/***
026 * This is a utility class providing a reader/writer capability required
027 * by the weatherTelnet, rexec, rshell, and rlogin example programs.
028 * The only point of the class is to hold the static method readWrite
029 * which spawns a reader thread and a writer thread.  The reader thread
030 * reads from a local input source (presumably stdin) and writes the
031 * data to a remote output destination.  The writer thread reads from
032 * a remote input source and writes to a local output destination.
033 * The threads terminate when the remote input source closes.
034 * <p>
035 ***/
036
037public final class IOUtil
038{
039
040    public static final void readWrite(final InputStream remoteInput,
041                                       final OutputStream remoteOutput,
042                                       final InputStream localInput,
043                                       final OutputStream localOutput)
044    {
045        Thread reader, writer;
046
047        reader = new Thread()
048                 {
049                     public void run()
050                     {
051                         int ch;
052
053                         try
054                         {
055                             while (!interrupted() && (ch = localInput.read()) != -1)
056                             {
057                                 remoteOutput.write(ch);
058                                 remoteOutput.flush();
059                             }
060                         }
061                         catch (IOException e)
062                         {
063                             //e.printStackTrace();
064                         }
065                     }
066                 }
067                 ;
068
069
070        writer = new Thread()
071                 {
072                     public void run()
073                     {
074                         try
075                         {
076                             Util.copyStream(remoteInput, localOutput);
077                         }
078                         catch (IOException e)
079                         {
080                             e.printStackTrace();
081                             System.exit(1);
082                         }
083                     }
084                 };
085
086
087        writer.setPriority(Thread.currentThread().getPriority() + 1);
088
089        writer.start();
090        reader.setDaemon(true);
091        reader.start();
092
093        try
094        {
095            writer.join();
096            reader.interrupt();
097        }
098        catch (InterruptedException e)
099        {
100        }
101    }
102
103}
104