org.springframework.batch.core.partition.support

Class AbstractPartitionHandler

java.lang.Object

org.springframework.batch.core.partition.support.AbstractPartitionHandler

All Implemented Interfaces:

PartitionHandler

Direct Known Subclasses:

TaskExecutorPartitionHandler

public abstract class AbstractPartitionHandler
extends Object
implements PartitionHandler

Base PartitionHandler implementation providing common base features. Subclasses are expected to implement only the doHandle(org.springframework.batch.core.StepExecution, java.util.Set) method which returns with the result of the execution(s) or an exception if the step failed to process.

Author:

Sebastien Gerard, Dave Syer

Constructor Summary

Constructors

Constructor and Description
AbstractPartitionHandler()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract Set<StepExecution>	doHandle(StepExecution masterStepExecution, Set<StepExecution> partitionStepExecutions) Executes the specified StepExecution instances and returns an updated view of them.
int	getGridSize() Returns the number of step executions.
Collection<StepExecution>	handle(StepExecutionSplitter stepSplitter, StepExecution masterStepExecution) Main entry point for PartitionHandler interface.
void	setGridSize(int gridSize) Passed to the StepExecutionSplitter in the handle(StepExecutionSplitter, StepExecution) method, instructing it how many StepExecution instances are required, ideally.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractPartitionHandler

public AbstractPartitionHandler()

Method Detail

doHandle

protected abstract Set<StepExecution> doHandle(StepExecution masterStepExecution,
                          Set<StepExecution> partitionStepExecutions)
                                        throws Exception

Executes the specified StepExecution instances and returns an updated view of them. Throws an Exception if anything goes wrong.

Parameters:

masterStepExecution - the whole partition execution

partitionStepExecutions - the StepExecution instances to execute

Returns:

an updated view of these completed StepExecution instances

Throws:

Exception - if anything goes wrong. This allows implementations to be liberal and rely on the caller to translate an exception into a step failure as necessary.

handle

public Collection<StepExecution> handle(StepExecutionSplitter stepSplitter,
                               StepExecution masterStepExecution)
                                 throws Exception

Description copied from interface: PartitionHandler

Main entry point for PartitionHandler interface. The splitter creates all the executions that need to be farmed out, along with their input parameters (in the form of their ExecutionContext). The master step execution is used to identify the partition and group together the results logically.

Specified by:

handle in interface PartitionHandler

Parameters:

stepSplitter - a strategy for generating a collection of StepExecution instances

masterStepExecution - the master step execution for the whole partition

Returns:

a collection of completed StepExecution instances

Throws:

Exception - if anything goes wrong. This allows implementations to be liberal and rely on the caller to translate an exception into a step failure as necessary.

See Also:

PartitionHandler.handle(StepExecutionSplitter, StepExecution)

getGridSize

public int getGridSize()

Returns the number of step executions.

Returns:

the number of step executions

setGridSize

public void setGridSize(int gridSize)

Passed to the StepExecutionSplitter in the handle(StepExecutionSplitter, StepExecution) method, instructing it how many StepExecution instances are required, ideally. The StepExecutionSplitter is allowed to ignore the grid size in the case of a restart, since the input data partitions must be preserved.

Parameters:

gridSize - the number of step executions that will be created