cz.cuni.amis.utils.process
Class ProcessExecution

java.lang.Object
  cz.cuni.amis.utils.process.ProcessExecution

public class ProcessExecution
extends Object

Class that wrapps the execution of the arbitrary process that is configured by ProcessExecutionConfig.

The class is not suitable for inheritance ... better copy-paste and adjust for yourself.

Author:

Jimmy

Field Summary

protected ProcessExecutionConfig	config Configuration of the process to run.
static Pattern	FORMAL_PARAM
protected Logger	log Log used by the object, specified during the construction.
protected Process	process When start()ed it contains the process.
protected cz.cuni.amis.utils.flag.Flag<Boolean>	running Flag whether the process is running, we're synchronizing access to this class on this flag.
protected Runnable	shutDownHook Task that will kill the process when user forgets to do so before the JVM is killed.
protected Thread	shutDownHookThread
static Pattern	SIMPLE_PARAM
protected cz.cuni.amis.utils.StreamSink	streamSinkError Sink for the STDERR of the process, it may be redirected to log.
protected cz.cuni.amis.utils.StreamSink	streamSinkOutput Sink for the STDOUT of the process, it may be redirected to log.
protected boolean	timedout Whether the process timed out or not.
protected Runnable	waitForEnd Task that is waiting for the end of the process to switch running back to false and shutdown all other utility threads (like sink).
protected Thread	waitForEndThread

Constructor Summary

ProcessExecution(ProcessExecutionConfig config, Logger log)

Method Summary

Process	getBotProcess() Process of the process (non-null if started).
Integer	getExitValue() Returns exit value of the process.
cz.cuni.amis.utils.flag.ImmutableFlag<Boolean>	getRunning() Flag of the state of the process.
boolean	isFailed() Tells whether the process has failed == timed out / exit value is not 0.
boolean	isFailed(boolean report) Tells whether the process has failed == timed out / exit value is not 0.
boolean	isRunning() Flag of the state of the process.
boolean	isTimeout() If ProcessExecutionConfig.getTimeout() is specified, this will indicate whether the started process has timed out or not.
protected void	shutdown(boolean waitForEndThread) Shutdowns the process and cleans-up everything, preparing the object to be start()ed again.
void	start() Start the process.
void	stop() Shuts down the process (if it is running, otherwise does nothing).
static String	substituteParams(String command, Logger log) Searches for $XXX or ${XXX} and substitute them with System.getenv() (prioritized) or System.getProperty(String).

Methods inherited from class java.lang.Object

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

Field Detail

config

protected ProcessExecutionConfig config

Configuration of the process to run.

running

protected cz.cuni.amis.utils.flag.Flag<Boolean> running

Flag whether the process is running, we're synchronizing access to this class on this flag.

Set to TRUE ONLY IN start() and back to FALSE ONLY IN shutdown(boolean). Do not alter the flag from anywhere else!

process

protected Process process

When start()ed it contains the process.

streamSinkOutput

protected cz.cuni.amis.utils.StreamSink streamSinkOutput

Sink for the STDOUT of the process, it may be redirected to log.

streamSinkError

protected cz.cuni.amis.utils.StreamSink streamSinkError

Sink for the STDERR of the process, it may be redirected to log.

log

protected Logger log

Log used by the object, specified during the construction.

shutDownHook

protected Runnable shutDownHook

Task that will kill the process when user forgets to do so before the JVM is killed.

shutDownHookThread

protected Thread shutDownHookThread

timedout

protected boolean timedout

Whether the process timed out or not.

waitForEnd

protected Runnable waitForEnd

Task that is waiting for the end of the process to switch running back to false and shutdown all other utility threads (like sink).

waitForEndThread

protected Thread waitForEndThread

SIMPLE_PARAM

public static final Pattern SIMPLE_PARAM

FORMAL_PARAM

public static final Pattern FORMAL_PARAM

Constructor Detail

ProcessExecution

public ProcessExecution(ProcessExecutionConfig config,
                        Logger log)

Parameters:

config - process execution configuration (contains path to file to run)

log - log to be used (stdout/stderr of the process will be redirected there as well with Level.INFO)

Method Detail

substituteParams

public static String substituteParams(String command,
                                      Logger log)

Searches for $XXX or ${XXX} and substitute them with System.getenv() (prioritized) or System.getProperty(String).

Parameters:

command -

Returns:

start

public void start()
           throws cz.cuni.amis.utils.exception.PogamutIOException

Start the process. Throws PogamutIOException if it fails to start the JVM.

It is wise to observe the state of the getRunning() flag to obtain the state of the process (whether the process is running or is dead). Usage of FlagListener is advised, see ImmutableFlag.addListener(FlagListener).

Throws:

cz.cuni.amis.utils.exception.PogamutIOException

shutdown

protected void shutdown(boolean waitForEndThread)

Shutdowns the process and cleans-up everything, preparing the object to be start()ed again.

Parameters:

waitForEndThread - whether we're being called from the waitForEnd thread.

stop

public void stop()

Shuts down the process (if it is running, otherwise does nothing).

getBotProcess

public Process getBotProcess()

Process of the process (non-null if started).

Returns:

getRunning

public cz.cuni.amis.utils.flag.ImmutableFlag<Boolean> getRunning()

Flag of the state of the process. True == process is running (has been started using start()), False == process was not started or has been already terminated, either by itself or via stop().

Returns:

isRunning

public boolean isRunning()

Flag of the state of the process. True == process is running (has been started using start()), False == process was not started or has been already terminated, either by itself or via stop().

Returns:

getExitValue

public Integer getExitValue()

Returns exit value of the process. If null is returned == process is still running / has never finished before.

Returns:

isTimeout

public boolean isTimeout()

If ProcessExecutionConfig.getTimeout() is specified, this will indicate whether the started process has timed out or not.

Returns:

isFailed

public boolean isFailed(boolean report)

Tells whether the process has failed == timed out / exit value is not 0.

True == process has failed.

False == process is running or process has finished OK.

Parameters:

report - whether the reason of failure / success should be reported

Returns:

isFailed

public boolean isFailed()

Tells whether the process has failed == timed out / exit value is not 0.

True == process has failed.

False == process is running or process has finished OK.

Returns: