org.springframework.batch.core.step.builder

Class PartitionStepBuilder

java.lang.Object

org.springframework.batch.core.step.builder.StepBuilderHelper<PartitionStepBuilder>

org.springframework.batch.core.step.builder.PartitionStepBuilder

public class PartitionStepBuilder
extends StepBuilderHelper<PartitionStepBuilder>

Step builder for PartitionStep instances. A partition step executes the same step (possibly remotely) multiple times with different input parameters (in the form of execution context). Useful for parallelization.

Since:

2.2

Author:

Dave Syer

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.batch.core.step.builder.StepBuilderHelper

StepBuilderHelper.CommonStepProperties

Field Summary

Fields inherited from class org.springframework.batch.core.step.builder.StepBuilderHelper

logger, properties

Constructor Summary

Constructors

Constructor and Description
PartitionStepBuilder(StepBuilderHelper<?> parent) Create a new builder initialized with any properties in the parent.

Method Summary

Methods

Modifier and Type	Method and Description
PartitionStepBuilder	aggregator(StepExecutionAggregator aggregator) Provide a step execution aggregator for aggregating partitioned step executions into a single result for the PartitionStep itself.
Step	build()
PartitionStepBuilder	gridSize(int gridSize) A hint to the splitter(StepExecutionSplitter) about how many step executions are required.
PartitionStepBuilder	partitioner(String slaveStepName, Partitioner partitioner) Add a partitioner which can be used to create a StepExecutionSplitter.
PartitionStepBuilder	partitionHandler(PartitionHandler partitionHandler) Provide an explicit partition handler that will carry out the work of the partition step.
PartitionStepBuilder	splitter(StepExecutionSplitter splitter) Provide an explicit StepExecutionSplitter instead of having one build from the partitioner(String, Partitioner).
PartitionStepBuilder	step(Step step) Provide an actual step instance to execute in parallel.
PartitionStepBuilder	taskExecutor(org.springframework.core.task.TaskExecutor taskExecutor) Provide a task executor to use when constructing a PartitionHandler from the step(Step).

Methods inherited from class org.springframework.batch.core.step.builder.StepBuilderHelper

allowStartIfComplete, enhance, getJobRepository, getName, getTransactionManager, isAllowStartIfComplete, listener, listener, repository, startLimit, transactionManager

Methods inherited from class java.lang.Object

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

Constructor Detail

PartitionStepBuilder

public PartitionStepBuilder(StepBuilderHelper<?> parent)

Create a new builder initialized with any properties in the parent. The parent is copied, so it can be re-used.

Parameters:

parent - a parent helper containing common step properties

Method Detail

partitioner

public PartitionStepBuilder partitioner(String slaveStepName,
                               Partitioner partitioner)

Add a partitioner which can be used to create a StepExecutionSplitter. Use either this or an explicit splitter(StepExecutionSplitter) but not both.

Parameters:

slaveStepName - the name of the slave step (used to construct step execution names)

partitioner - a partitioner to use

Returns:

this for fluent chaining

step

public PartitionStepBuilder step(Step step)

Provide an actual step instance to execute in parallel. If an explicit partitionHandler(PartitionHandler) is provided, the step is optional and is only used to extract configuration data (name and other basic properties of a step).

Parameters:

step - a step to execute in parallel

Returns:

this for fluent chaining

taskExecutor

public PartitionStepBuilder taskExecutor(org.springframework.core.task.TaskExecutor taskExecutor)

Provide a task executor to use when constructing a PartitionHandler from the step(Step). Mainly used for running a step locally in parallel, but can be used to execute remotely if the step is remote. Not used if an explicit partitionHandler(PartitionHandler) is provided.

Parameters:

taskExecutor - a task executor to use when executing steps in parallel

Returns:

this for fluent chaining

partitionHandler

public PartitionStepBuilder partitionHandler(PartitionHandler partitionHandler)

Provide an explicit partition handler that will carry out the work of the partition step. The partition handler is the main SPI for adapting a partition step to a specific distributed computation environment. Optional if you only need local or remote processing through the Step interface.

Parameters:

partitionHandler - a partition handler

Returns:

this for fluent chaining

See Also:

for setting up a default handler that works with a local or remote Step

gridSize

public PartitionStepBuilder gridSize(int gridSize)

A hint to the splitter(StepExecutionSplitter) about how many step executions are required. If running locally or remotely through a taskExecutor(TaskExecutor) determines precisely the number of step execution sin the first attempt at a partition step execution.

Parameters:

gridSize - the grid size

Returns:

this for fluent chaining

splitter

public PartitionStepBuilder splitter(StepExecutionSplitter splitter)

Provide an explicit StepExecutionSplitter instead of having one build from the partitioner(String, Partitioner). USeful if you need more control over the splitting.

Parameters:

splitter - a step execution splitter

Returns:

this for fluent chaining

aggregator

public PartitionStepBuilder aggregator(StepExecutionAggregator aggregator)

Provide a step execution aggregator for aggregating partitioned step executions into a single result for the PartitionStep itself. Default is a simple implementation that works in most cases.

Parameters:

aggregator - a step execution aggregator

Returns:

this for fluent chaining

build

public Step build()