edu.isi.pegasus.common.util
Class StreamGobbler

java.lang.Object
  java.lang.Thread
      edu.isi.pegasus.common.util.StreamGobbler

All Implemented Interfaces:

Runnable

public class StreamGobbler
extends Thread

A Stream gobbler class to take care of reading from a stream and optionally write out to another stream. Allows for non blocking reads on both stdout and stderr, when invoking a process through Runtime.exec(). Also, the user can specify a callback that is called whenever anything is read from the stream.

Author:

Karan Vahi

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

private StreamGobblerCallback	mCallback The callback to be used.
private InputStream	mIPStream The input stream that is to be read from.
private LogManager	mLogger The handle to the logging object.
private OutputStream	mOPStream The output stream to which the contents have to be redirected to.
private String	mPrompt The prompt that is to be written to the output stream.
private boolean	mStarted A boolean indicating whether the thread has started or not.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

StreamGobbler(InputStream is, StreamGobblerCallback callback)
The overloaded constructor.

Method Summary

void	close() Closes the underneath input and output stream that were opened.
protected void	finalize() Closes the open connections to the streams whenever this object is destroyed.
void	redirect(OutputStream ops, String prompt) Sets the output stream to which to redirect the contents of the input stream.
void	run() The main method of the gobbler, that does all the work.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

mIPStream

private InputStream mIPStream

The input stream that is to be read from.

mOPStream

private OutputStream mOPStream

The output stream to which the contents have to be redirected to.

mCallback

private StreamGobblerCallback mCallback

The callback to be used.

mPrompt

private String mPrompt

The prompt that is to be written to the output stream.

mStarted

private boolean mStarted

A boolean indicating whether the thread has started or not.

mLogger

private LogManager mLogger

The handle to the logging object.

Constructor Detail

StreamGobbler

public StreamGobbler(InputStream is,
                     StreamGobblerCallback callback)

The overloaded constructor.

Parameters:

is - the input stream from which to read from.

callback - the callback to call when a line is read.

Method Detail

redirect

public void redirect(OutputStream ops,
                     String prompt)

Sets the output stream to which to redirect the contents of the input stream.

Parameters:

ops - the output stream.

prompt - the prompt for the output stream.

run

public void run()

The main method of the gobbler, that does all the work.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

finalize

protected void finalize()

Closes the open connections to the streams whenever this object is destroyed.

Overrides:

finalize in class Object

close

public void close()

Closes the underneath input and output stream that were opened.