org.mmbase.util.externalprocess

Class ProcessClosure

java.lang.Object

org.mmbase.util.externalprocess.ProcessClosure

public class ProcessClosure
extends Object

ProcessClosure handles the reading of the stdout and stderr of a external process. A reader can block the calling thread until it is finished reading (readBlocking). Or the reader can immidiately return when reading of the stdout and stderr begins (readNonBlocking). ProcessClosure handles the writing of the stdin of a external process. A writer can block the calling thread until it is finished writing to the stdin and reading the stdout and stderr (writeBlocking). Or the writer can imidiately return when writing to stdin and reading of the stdout and sterr begins (writeNonBlocking)

Since:

MMBase-1.6

Version:

$Id$

Author:

Nico Klasens (Finalist IT Group)

Field Summary

Fields

Modifier and Type	Field and Description
protected long	count
protected OutputStream	error The stream where data is written to when piped from stderr
protected StreamCopyThread	errorReader Thread for copying bytes from stderr to error
protected InputStream	input The stream where data is read from to pipe it to stdin
protected StreamCopyThread	inputWriter Thread for copying bytes from input to stdin
protected String	name the name of the process closure
protected OutputStream	output The stream where data is written to when piped from stdout
protected StreamCopyThread	outputReader Thread for copying bytes from stdout to output
protected Process	process the process object representing the external process

Constructor Summary

Constructors

Constructor and Description
ProcessClosure(String name, Process process, InputStream inputStream, OutputStream outputStream, OutputStream errorStream) Creates a process reader .

Method Summary

Modifier and Type	Method and Description
long	getCount()
boolean	isAlive() Process closure is alive when the external process and writer/reader threads are still busy
void	readBlocking() read data from the external process and block the calling thread until reading is finished
void	readNonBlocking() read data from the external process without blocking the calling thread
void	terminate() Forces the termination of the launched process
protected void	waitForProcess() wait for the external process.to end
protected void	waitForReaders() wait for the reading threads to finish copying
protected void	waitForWriter() wait for the writing thread to finish copying
void	writeBlocking() write data to the external process and block the calling thread until writing and reading is finished
void	writeNonBlocking() write data to the external process without blocking the calling thread

Methods inherited from class java.lang.Object

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

Field Detail

name

protected String name

the name of the process closure

process

protected Process process

the process object representing the external process

input

protected InputStream input

The stream where data is read from to pipe it to stdin

output

protected OutputStream output

The stream where data is written to when piped from stdout

error

protected OutputStream error

The stream where data is written to when piped from stderr

inputWriter

protected StreamCopyThread inputWriter

Thread for copying bytes from input to stdin

outputReader

protected StreamCopyThread outputReader

Thread for copying bytes from stdout to output

errorReader

protected StreamCopyThread errorReader

Thread for copying bytes from stderr to error

count

protected long count

Constructor Detail

ProcessClosure

public ProcessClosure(String name,
                      Process process,
                      InputStream inputStream,
                      OutputStream outputStream,
                      OutputStream errorStream)

Creates a process reader .

Parameters:

name - the name of the reader

inputStream - process stdin is read from this stream. Can be null, if not interested in writing the input

outputStream - process stdout is written to this stream. Can be null, if not interested in reading the output

errorStream - porcess stderr is written to this stream. Can be null, if not interested in reading the output

Method Detail

readNonBlocking

public void readNonBlocking()

read data from the external process without blocking the calling thread

writeNonBlocking

public void writeNonBlocking()

write data to the external process without blocking the calling thread

getCount

public long getCount()

readBlocking

public void readBlocking()

read data from the external process and block the calling thread until reading is finished

writeBlocking

public void writeBlocking()

write data to the external process and block the calling thread until writing and reading is finished

waitForProcess

protected void waitForProcess()

wait for the external process.to end

waitForReaders

protected void waitForReaders()

wait for the reading threads to finish copying

waitForWriter

protected void waitForWriter()

wait for the writing thread to finish copying

isAlive

public boolean isAlive()

Process closure is alive when the external process and writer/reader threads are still busy

Returns:

true if is alive and false otherwise

terminate

public void terminate()

Forces the termination of the launched process