com.trilead.ssh2
Class StreamGobbler

java.lang.Object
  java.io.InputStream
      com.trilead.ssh2.StreamGobbler

All Implemented Interfaces:

java.io.Closeable

public class StreamGobbler
extends java.io.InputStream

A StreamGobbler is an InputStream that uses an internal worker thread to constantly consume input from another InputStream. It uses a buffer to store the consumed data. The buffer size is automatically adjusted, if needed.

This class is sometimes very convenient - if you wrap a session's STDOUT and STDERR InputStreams with instances of this class, then you don't have to bother about the shared window of STDOUT and STDERR in the low level SSH-2 protocol, since all arriving data will be immediatelly consumed by the worker threads. Also, as a side effect, the streams will be buffered (e.g., single byte read() operations are faster).

Other SSH for Java libraries include this functionality by default in their STDOUT and STDERR InputStream implementations, however, please be aware that this approach has also a downside:

If you do not call the StreamGobbler's read() method often enough and the peer is constantly sending huge amounts of data, then you will sooner or later encounter a low memory situation due to the aggregated data (well, it also depends on the Java heap size). Joe Average will like this class anyway - a paranoid programmer would never use such an approach.

The term "StreamGobbler" was taken from an article called "When Runtime.exec() won't", see http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html.

Version:

$Id: StreamGobbler.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $

Author:

Christian Plattner, plattner@trilead.com

Constructor Summary

StreamGobbler(java.io.InputStream is, java.io.File log, int buffer_size)

Method Summary

int	available()
void	close()
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
void	writeToFile(byte[] buffer)

Methods inherited from class java.io.InputStream

mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StreamGobbler

public StreamGobbler(java.io.InputStream is,
                     java.io.File log,
                     int buffer_size)

Method Detail

writeToFile

public void writeToFile(byte[] buffer)

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

available

public int available()
              throws java.io.IOException

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException