org.springframework.batch.core.partition.support
Class SimpleStepExecutionSplitter

java.lang.Object
  org.springframework.batch.core.partition.support.SimpleStepExecutionSplitter

All Implemented Interfaces:

StepExecutionSplitter

public class SimpleStepExecutionSplitter
extends Object
implements StepExecutionSplitter

Generic implementation of StepExecutionSplitter that delegates to a Partitioner to generate ExecutionContext instances. Takes care of restartability and identifying the step executions from previous runs of the same job. The generated StepExecution instances have names that identify them uniquely in the partition. The name is constructed from a base (name of the target step) plus a suffix taken from the Partitioner identifiers, separated by a colon, e.g. {step1:partition0, step1:partition1, ...}.

Since:

2.0

Author:

Dave Syer

Constructor Summary

SimpleStepExecutionSplitter(JobRepository jobRepository, Step step)

SimpleStepExecutionSplitter(JobRepository jobRepository, Step step, Partitioner partitioner)
Construct a SimpleStepExecutionSplitter from its mandatory properties.

Method Summary

String	getStepName() The name of the step configuration that will be executed remotely.
Set<StepExecution>	split(StepExecution stepExecution, int gridSize) Partition the provided StepExecution into a set of parallel executable instances with the same parent JobExecution.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleStepExecutionSplitter

public SimpleStepExecutionSplitter(JobRepository jobRepository,
                                   Step step)

SimpleStepExecutionSplitter

public SimpleStepExecutionSplitter(JobRepository jobRepository,
                                   Step step,
                                   Partitioner partitioner)

Construct a SimpleStepExecutionSplitter from its mandatory properties.

Parameters:

jobRepository - the JobRepository

step - the target step (a local version of it)

partitioner - a Partitioner to use for generating input parameters

Method Detail

getStepName

public String getStepName()

Description copied from interface: StepExecutionSplitter

The name of the step configuration that will be executed remotely. Remote workers are going to execute a the same step for each execution context in the partition.

Specified by:

getStepName in interface StepExecutionSplitter

Returns:

the name of the step that will execute the business logic

See Also:

StepExecutionSplitter.getStepName()

split

public Set<StepExecution> split(StepExecution stepExecution,
                                int gridSize)
                         throws JobExecutionException

Description copied from interface: StepExecutionSplitter

Partition the provided StepExecution into a set of parallel executable instances with the same parent JobExecution. The grid size will be treated as a hint for the size of the collection to be returned. It may or may not correspond to the physical size of an execution grid.

On a restart clients of the StepExecutionSplitter should expect it to reconstitute the state of the last failed execution and only return those executions that need to be restarted. Thus the grid size hint will be ignored on a restart.

Specified by:

split in interface StepExecutionSplitter

Parameters:

stepExecution - the StepExecution to be partitioned.

gridSize - a hint for the splitter if the size of the grid is known

Returns:

a set of StepExecution instances for remote processing

Throws:

JobExecutionException - if the split cannot be made

See Also:

StepExecutionSplitter.split(StepExecution, int)