java.lang.Object
- org.springframework.batch.core.listener.StepExecutionListenerSupport
- - org.springframework.batch.core.step.tasklet.SystemCommandTasklet

All Implemented Interfaces:
StoppableTasklet, Tasklet, StepExecutionListener, StepListener, org.springframework.beans.factory.InitializingBean
```
public class SystemCommandTasklet
extends StepExecutionListenerSupport
implements StoppableTasklet, org.springframework.beans.factory.InitializingBean
```
Tasklet that executes a system command. The system command is executed asynchronously using injected setTaskExecutor(TaskExecutor) - timeout value is required to be set, so that the batch job does not hang forever if the external process hangs. Tasklet periodically checks for termination status (i.e. setCommand(String) finished its execution or setTimeout(long) expired or job was interrupted). The check interval is given by setTerminationCheckInterval(long). When job interrupt is detected tasklet's execution is terminated immediately by throwing JobInterruptedException. setInterruptOnCancel(boolean) specifies whether the tasklet should attempt to interrupt the thread that executes the system command if it is still running when tasklet exits (abnormally).
Author:
Robert Kasanicky, Will Schipp

Field Summary
Fields
Modifier and Type Field Description
protected static org.apache.commons.logging.Log logger

Constructor Summary
Constructors
Constructor Description
SystemCommandTasklet()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`afterPropertiesSet()`
`void`	`beforeStep(StepExecution stepExecution)`	Get a reference to `StepExecution` for interrupt checks during system command execution.
`RepeatStatus`	`execute(StepContribution contribution, ChunkContext chunkContext)`	Execute system command and map its exit code to `ExitStatus` using `SystemProcessExitCodeMapper`.
`void`	`setCommand(java.lang.String command)`
`void`	`setEnvironmentParams(java.lang.String[] envp)`
`void`	`setInterruptOnCancel(boolean interruptOnCancel)`	If `true` tasklet will attempt to interrupt the thread executing the system command if `setTimeout(long)` has been exceeded or user interrupts the job.
`void`	`setJobExplorer(JobExplorer jobExplorer)`
`void`	`setSystemProcessExitCodeMapper(SystemProcessExitCodeMapper systemProcessExitCodeMapper)`
`void`	`setTaskExecutor(org.springframework.core.task.TaskExecutor taskExecutor)`	Sets the task executor that will be used to execute the system command NB! Avoid using a synchronous task executor
`void`	`setTerminationCheckInterval(long checkInterval)`	The time interval how often the tasklet will check for termination status.
`void`	`setTimeout(long timeout)`	Timeout in milliseconds.
`void`	`setWorkingDirectory(java.lang.String dir)`
`void`	`stop()`	Will interrupt the thread executing the system command only if `setInterruptOnCancel(boolean)` has been set to true.

Methods inherited from class org.springframework.batch.core.listener.StepExecutionListenerSupport
afterStep

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - logger
```
protected static final org.apache.commons.logging.Log logger
```
- Constructor Detail
  - SystemCommandTasklet
```
public SystemCommandTasklet()
```
- Method Detail
  - execute
```
public RepeatStatus execute(StepContribution contribution,
                            ChunkContext chunkContext)
                     throws java.lang.Exception
```
    Execute system command and map its exit code to ExitStatus using SystemProcessExitCodeMapper.
    Specified by:
    execute in interface Tasklet
    Parameters:
    contribution - mutable state to be passed back to update the current step execution
    chunkContext - attributes shared between invocations but not between restarts
    Returns:
    an RepeatStatus indicating whether processing is continuable. Returning null is interpreted as RepeatStatus.FINISHED
    Throws:
    java.lang.Exception - thrown if error occurs during execution.
  - setCommand
```
public void setCommand(java.lang.String command)
```
    Parameters:
    command - command to be executed in a separate system process
  - setEnvironmentParams
```
public void setEnvironmentParams(java.lang.String[] envp)
```
    Parameters:
    envp - environment parameter values, inherited from parent process when not set (or set to null).
  - setWorkingDirectory
```
public void setWorkingDirectory(java.lang.String dir)
```
    Parameters:
    dir - working directory of the spawned process, inherited from parent process when not set (or set to null).
  - afterPropertiesSet
```
public void afterPropertiesSet()
                        throws java.lang.Exception
```
    Specified by:
    afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean
    Throws:
    java.lang.Exception
  - setJobExplorer
```
public void setJobExplorer(JobExplorer jobExplorer)
```
  - setSystemProcessExitCodeMapper
```
public void setSystemProcessExitCodeMapper(SystemProcessExitCodeMapper systemProcessExitCodeMapper)
```
    Parameters:
    systemProcessExitCodeMapper - maps system process return value to ExitStatus returned by Tasklet. SimpleSystemProcessExitCodeMapper is used by default.
  - setTimeout
```
public void setTimeout(long timeout)
```
    Timeout in milliseconds.
    Parameters:
    timeout - upper limit for how long the execution of the external program is allowed to last.
  - setTerminationCheckInterval
```
public void setTerminationCheckInterval(long checkInterval)
```
    The time interval how often the tasklet will check for termination status.
    Parameters:
    checkInterval - time interval in milliseconds (1 second by default).
  - beforeStep
```
public void beforeStep(StepExecution stepExecution)
```
    Get a reference to StepExecution for interrupt checks during system command execution.
    Specified by:
    beforeStep in interface StepExecutionListener
    Overrides:
    beforeStep in class StepExecutionListenerSupport
    Parameters:
    stepExecution - instance of StepExecution.
  - setTaskExecutor
```
public void setTaskExecutor(org.springframework.core.task.TaskExecutor taskExecutor)
```
    Sets the task executor that will be used to execute the system command NB! Avoid using a synchronous task executor
    Parameters:
    taskExecutor - instance of TaskExecutor.
  - setInterruptOnCancel
```
public void setInterruptOnCancel(boolean interruptOnCancel)
```
    If true tasklet will attempt to interrupt the thread executing the system command if setTimeout(long) has been exceeded or user interrupts the job. false by default
    Parameters:
    interruptOnCancel - boolean determines if process should be interrupted
  - stop
```
public void stop()
```
    Will interrupt the thread executing the system command only if setInterruptOnCancel(boolean) has been set to true. Otherwise the underlying command will be allowed to finish before the tasklet ends.
    Specified by:
    stop in interface StoppableTasklet
    Since:
    3.0
    See Also:
    StoppableTasklet.stop()

Class SystemCommandTasklet

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.springframework.batch.core.listener.StepExecutionListenerSupport

Methods inherited from class java.lang.Object

Field Detail

logger

Constructor Detail

SystemCommandTasklet

Method Detail

execute

setCommand

setEnvironmentParams

setWorkingDirectory

afterPropertiesSet

setJobExplorer

setSystemProcessExitCodeMapper

setTimeout

setTerminationCheckInterval

beforeStep

setTaskExecutor

setInterruptOnCancel

stop