org.springframework.batch.core.step.tasklet

Class TaskletStep

java.lang.Object

org.springframework.batch.core.step.AbstractStep

org.springframework.batch.core.step.tasklet.TaskletStep

All Implemented Interfaces:

Step, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.InitializingBean

Direct Known Subclasses:

BatchletStep

public class TaskletStep
extends AbstractStep

Simple implementation of executing the step as a call to a Tasklet, possibly repeated, and each call surrounded by a transaction. The structure is therefore that of a loop with transaction boundary inside the loop. The loop is controlled by the step operations ( setStepOperations(RepeatOperations)).

Clients can use interceptors in the step operations to intercept or listen to the iteration on a step-wide basis, for instance to get a callback when the step is complete. Those that want callbacks at the level of an individual tasks, can specify interceptors for the chunk operations.

Author:

Dave Syer, Lucas Ward, Ben Hale, Robert Kasanicky, Michael Minella, Will Schipp

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	TASKLET_TYPE_KEY

Fields inherited from interface org.springframework.batch.core.Step

STEP_TYPE_KEY

Constructor Summary

Constructors

Constructor and Description
TaskletStep() Default constructor.
TaskletStep(java.lang.String name)

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet()
protected void	close(ExecutionContext ctx) Extension point for subclasses to provide callbacks to their collaborators at the end of a step (right at the end of the finally block), to close or release resources.
protected java.util.concurrent.Semaphore	createSemaphore() Extension point mainly for test purposes so that the behaviour of the lock can be manipulated to simulate various pathologies.
protected void	doExecute(StepExecution stepExecution) Process the step and update its context so that progress can be monitored by the caller.
Tasklet	getTasklet() retrieve the tasklet - helper method for JobOperator
protected void	open(ExecutionContext ctx) Extension point for subclasses to provide callbacks to their collaborators at the beginning of a step, to open or acquire resources.
void	registerChunkListener(ChunkListener listener) Register a chunk listener for callbacks at the appropriate stages in a step execution.
void	registerStream(ItemStream stream) Register a single ItemStream for callbacks to the stream interface.
void	setChunkListeners(ChunkListener[] listeners) Register each of the objects as listeners.
void	setInterruptionPolicy(StepInterruptionPolicy interruptionPolicy) Setter for the StepInterruptionPolicy.
void	setStepOperations(RepeatOperations stepOperations) The RepeatOperations to use for the outer loop of the batch processing.
void	setStreams(ItemStream[] streams) Register each of the streams for callbacks at the appropriate time in the step.
void	setTasklet(Tasklet tasklet) Public setter for the Tasklet.
void	setTransactionAttribute(org.springframework.transaction.interceptor.TransactionAttribute transactionAttribute) Public setter for the TransactionAttribute.
void	setTransactionManager(org.springframework.transaction.PlatformTransactionManager transactionManager) Public setter for the PlatformTransactionManager.

Methods inherited from class org.springframework.batch.core.step.AbstractStep

doExecutionRegistration, doExecutionRelease, execute, getCompositeListener, getJobRepository, getName, getStartLimit, isAllowStartIfComplete, registerStepExecutionListener, setAllowStartIfComplete, setBeanName, setJobRepository, setName, setStartLimit, setStepExecutionListeners, toString

Methods inherited from class java.lang.Object

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

Field Detail

TASKLET_TYPE_KEY

public static final java.lang.String TASKLET_TYPE_KEY

See Also:

Constant Field Values

Constructor Detail

TaskletStep

public TaskletStep()

Default constructor.

TaskletStep

public TaskletStep(java.lang.String name)

Parameters:

name -

Method Detail

afterPropertiesSet

public void afterPropertiesSet()
                        throws java.lang.Exception

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Overrides:

afterPropertiesSet in class AbstractStep

Throws:

java.lang.Exception

setTransactionManager

public void setTransactionManager(org.springframework.transaction.PlatformTransactionManager transactionManager)

Public setter for the PlatformTransactionManager.

Parameters:

transactionManager - the transaction manager to set

setTransactionAttribute

public void setTransactionAttribute(org.springframework.transaction.interceptor.TransactionAttribute transactionAttribute)

Public setter for the TransactionAttribute.

Parameters:

transactionAttribute - the TransactionAttribute to set

setTasklet

public void setTasklet(Tasklet tasklet)

Public setter for the Tasklet.

Parameters:

tasklet - the Tasklet to set

registerChunkListener

public void registerChunkListener(ChunkListener listener)

Register a chunk listener for callbacks at the appropriate stages in a step execution.

Parameters:

listener - a ChunkListener

setChunkListeners

public void setChunkListeners(ChunkListener[] listeners)

Register each of the objects as listeners.

Parameters:

listeners - an array of listener objects of known types.

setStreams

public void setStreams(ItemStream[] streams)

Register each of the streams for callbacks at the appropriate time in the step. The ItemReader and ItemWriter are automatically registered, but it doesn't hurt to also register them here. Injected dependencies of the reader and writer are not automatically registered, so if you implement ItemWriter using delegation to another object which itself is a ItemStream, you need to register the delegate here.

Parameters:

streams - an array of ItemStream objects.

registerStream

public void registerStream(ItemStream stream)

Register a single ItemStream for callbacks to the stream interface.

Parameters:

stream -

setStepOperations

public void setStepOperations(RepeatOperations stepOperations)

The RepeatOperations to use for the outer loop of the batch processing. Should be set up by the caller through a factory. Defaults to a plain RepeatTemplate.

Parameters:

stepOperations - a RepeatOperations instance.

setInterruptionPolicy

public void setInterruptionPolicy(StepInterruptionPolicy interruptionPolicy)

Setter for the StepInterruptionPolicy. The policy is used to check whether an external request has been made to interrupt the job execution.

Parameters:

interruptionPolicy - a StepInterruptionPolicy

doExecute

protected void doExecute(StepExecution stepExecution)
                  throws java.lang.Exception

Process the step and update its context so that progress can be monitored by the caller. The step is broken down into chunks, each one executing in a transaction. The step and its execution and execution context are all given an up to date BatchStatus, and the JobRepository is used to store the result. Various reporting information are also added to the current context governing the step execution, which would normally be available to the caller through the step's ExecutionContext.

Specified by:

doExecute in class AbstractStep

Parameters:

stepExecution - the current step context

Throws:

JobInterruptedException - if the step or a chunk is interrupted

java.lang.RuntimeException - if there is an exception during a chunk execution

java.lang.Exception

createSemaphore

protected java.util.concurrent.Semaphore createSemaphore()

Extension point mainly for test purposes so that the behaviour of the lock can be manipulated to simulate various pathologies.

Returns:

a semaphore for locking access to the JobRepository

close

protected void close(ExecutionContext ctx)
              throws java.lang.Exception

Description copied from class: AbstractStep

Extension point for subclasses to provide callbacks to their collaborators at the end of a step (right at the end of the finally block), to close or release resources. Does nothing by default.

Overrides:

close in class AbstractStep

Parameters:

ctx - the ExecutionContext to use

Throws:

java.lang.Exception

open

protected void open(ExecutionContext ctx)
             throws java.lang.Exception

Description copied from class: AbstractStep

Extension point for subclasses to provide callbacks to their collaborators at the beginning of a step, to open or acquire resources. Does nothing by default.

Overrides:

open in class AbstractStep

Parameters:

ctx - the ExecutionContext to use

Throws:

java.lang.Exception

getTasklet

public Tasklet getTasklet()

retrieve the tasklet - helper method for JobOperator

Returns:

the Tasklet instance being executed within this step