org.springframework.batch.core.partition
Interface StepExecutionSplitter

All Known Implementing Classes:

SimpleStepExecutionSplitter

public interface StepExecutionSplitter

Strategy interface for generating input contexts for a partitioned step execution independent from the fabric they are going to run on.

Since:

2.0

Author:

Dave Syer

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.

Method Detail

getStepName

String getStepName()

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.

Returns:

the name of the step that will execute the business logic

split

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

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.

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