org.jppf.server.protocol

Class CommandLineTask

java.lang.Object

org.jppf.server.protocol.JPPFTask

org.jppf.server.protocol.CommandLineTask

All Implemented Interfaces:

Serializable, Runnable, EventListener, Task<Object>, ProcessWrapperEventListener

public abstract class CommandLineTask
extends JPPFTask
implements ProcessWrapperEventListener

Instances of this class encapsulate the execution of an external process, program or shell script.
This task starts and external process using command line arguments, environment variables, and a list of input and/or output files to use or generated by the external process.
This task also captures the standard and error output (i.e. equivalent to System.out and System.err) of the external process.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CommandLineTask() Default constructor.
CommandLineTask(Map<String,String> env, String startDir, String... commands) Create an instance of this class and set the parameters of the external process or script to launch.
CommandLineTask(String... commands) Create an instance of this class and set the parameters of the external process or script to launch.

Method Summary

Methods

Modifier and Type	Method and Description
void	errorStreamAltered(ProcessWrapperEvent event) Notification that the process has written to its error stream.
List<String>	getCommandList() Get the list of command-line arguments.
Map<String,String>	getEnv() Get the environment variables to set.
String	getErrorOutput() Get the content of the error output for the process.
int	getExitCode() Get the exit code returned by the sub-process.
Process	getProcess() Get the process that is launched by this task.
String	getStandardOutput() Get the content of the standard output for the process.
String	getStartDir() Get the directory to start the command in.
boolean	isCaptureOutput() Determines whether the process output is captured.
int	launchProcess() Run the external process or script.
void	outputStreamAltered(ProcessWrapperEvent event) Notification that the process has written to its output stream.
void	setCaptureOutput(boolean captureOutput) Specifies whether the process output is captured.
void	setCommandList(List<String> commandList) Set the list of command-line arguments.
void	setCommandList(String... commands) Set the list of command-line arguments.
void	setEnv(Map<String,String> env) Get the environment variables to set.
void	setStartDir(String startDir) Set the directory to start the command in.

Methods inherited from class org.jppf.server.protocol.JPPFTask

compute, getDataProvider, getException, getId, getPosition, getResult, getTaskObject, getTimeoutSchedule, isInNode, onCancel, onTimeout, setDataProvider, setException, setId, setPosition, setResult, setTimeoutSchedule

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jppf.node.protocol.Task

onRestart

Methods inherited from interface java.lang.Runnable

run

Constructor Detail

CommandLineTask

public CommandLineTask()

Default constructor.

CommandLineTask

public CommandLineTask(String... commands)

Create an instance of this class and set the parameters of the external process or script to launch.

Parameters:

commands - the list of command-line arguments.

CommandLineTask

public CommandLineTask(Map<String,String> env,
               String startDir,
               String... commands)

Create an instance of this class and set the parameters of the external process or script to launch.

Parameters:

env - the environment variables to set.

startDir - the directory to start the command in.

commands - the list of command-line arguments.

Method Detail

launchProcess

public int launchProcess()
                  throws Exception

Run the external process or script.

Returns:

the exit code returned by the sub-process.

Throws:

Exception - if an error occurs.

isCaptureOutput

public boolean isCaptureOutput()

Determines whether the process output is captured.

Returns:

true if the output is captured, false otherwise.

setCaptureOutput

public void setCaptureOutput(boolean captureOutput)

Specifies whether the process output is captured.

Parameters:

captureOutput - true if the output is captured, false otherwise.

getStandardOutput

public String getStandardOutput()

Get the content of the standard output for the process.

Returns:

the output as a string.

getErrorOutput

public String getErrorOutput()

Get the content of the error output for the process.

Returns:

the output as a string.

getCommandList

public List<String> getCommandList()

Get the list of command-line arguments.

Returns:

a list of arguments as strings.

setCommandList

public void setCommandList(List<String> commandList)

Set the list of command-line arguments.

Parameters:

commandList - a list of arguments as strings.

setCommandList

public void setCommandList(String... commands)

Set the list of command-line arguments.

Parameters:

commands - a list of arguments as strings.

getEnv

public Map<String,String> getEnv()

Get the environment variables to set.

Returns:

a map of variable names to their corresponding values.

setEnv

public void setEnv(Map<String,String> env)

Get the environment variables to set.

Parameters:

env - a map of variable names to their corresponding values.

getStartDir

public String getStartDir()

Get the directory to start the command in.

Returns:

the start directory as a string.

setStartDir

public void setStartDir(String startDir)

Set the directory to start the command in.

Parameters:

startDir - the start directory as a string.

outputStreamAltered

public void outputStreamAltered(ProcessWrapperEvent event)

Notification that the process has written to its output stream.

Specified by:

outputStreamAltered in interface ProcessWrapperEventListener

Parameters:

event - encapsulates the output stream's content.

See Also:

ProcessWrapperEventListener.outputStreamAltered(org.jppf.process.event.ProcessWrapperEvent)

errorStreamAltered

public void errorStreamAltered(ProcessWrapperEvent event)

Notification that the process has written to its error stream.

Specified by:

errorStreamAltered in interface ProcessWrapperEventListener

Parameters:

event - encapsulate the error stream's content.

See Also:

ProcessWrapperEventListener.errorStreamAltered(org.jppf.process.event.ProcessWrapperEvent)

getExitCode

public int getExitCode()

Get the exit code returned by the sub-process.

Returns:

the value of the exit code returned by the sub-process. A negative value indicates the process was never launched or never returned.

See Also:

Process.waitFor()

getProcess

public Process getProcess()

Get the process that is launched by this task.

Returns:

a Process instance.