org.springframework.batch.core.jsr.step.item

Class JsrChunkProcessor<I,O>

java.lang.Object

org.springframework.batch.core.jsr.step.item.JsrChunkProcessor<I,O>

Type Parameters:

I - The input type for the step

O - The output type for the step

All Implemented Interfaces:

ChunkProcessor<I>

Direct Known Subclasses:

JsrFaultTolerantChunkProcessor

public class JsrChunkProcessor<I,O>
extends java.lang.Object
implements ChunkProcessor<I>

ChunkProcessor implementation that implements JSR-352's chunking pattern (read and process in a loop until the chunk is complete then write). This implementation is responsible for all three phases of chunk based processing (reading, processing and writing).

Author:

Michael Minella

Constructor Summary

Constructors

Constructor and Description
JsrChunkProcessor()
JsrChunkProcessor(ItemReader<? extends I> reader, ItemProcessor<? super I,? extends O> processor, ItemWriter<? super O> writer, RepeatOperations repeatTemplate)

Method Summary

Modifier and Type	Method and Description
protected void	doPersist(StepContribution contribution, Chunk<O> chunk) Implements writing and all related listener calls
protected I	doProvide(StepContribution contribution, Chunk<I> chunk) Implements reading as well as any related listener calls required.
protected O	doTransform(I item) Implements processing and all related listener calls.
protected MulticasterBatchListener<I,O>	getListener()
protected void	persist(StepContribution contribution, Chunk<O> chunk) Responsible for the writing portion of the chunking loop.
void	process(StepContribution contribution, Chunk<I> chunk) Loops through reading (via provide(StepContribution, Chunk) and processing (via transform(StepContribution, Object)) until the chunk is complete.
protected I	provide(StepContribution contribution, Chunk<I> chunk) Responsible for the reading portion of the chunking loop.
void	registerListener(StepListener listener) Register a listener for callbacks at the appropriate stages in a process.
void	setListeners(java.util.List<? extends StepListener> listeners) Register some StepListeners with the handler.
protected O	transform(StepContribution contribution, I item) Responsible for the processing portion of the chunking loop.

Methods inherited from class java.lang.Object

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

Constructor Detail

JsrChunkProcessor

public JsrChunkProcessor()

JsrChunkProcessor

public JsrChunkProcessor(ItemReader<? extends I> reader,
                         ItemProcessor<? super I,? extends O> processor,
                         ItemWriter<? super O> writer,
                         RepeatOperations repeatTemplate)

Method Detail

getListener

protected MulticasterBatchListener<I,O> getListener()

process

public void process(StepContribution contribution,
                    Chunk<I> chunk)
             throws java.lang.Exception

Loops through reading (via provide(StepContribution, Chunk) and processing (via transform(StepContribution, Object)) until the chunk is complete. Once the chunk is complete, the results are written (via persist(StepContribution, Chunk).

Specified by:

process in interface ChunkProcessor<I>

Parameters:

contribution - a StepContribution

chunk - a Chunk

Throws:

java.lang.Exception

See Also:

ChunkProcessor.process(StepContribution, Chunk)

setListeners

public void setListeners(java.util.List<? extends StepListener> listeners)

Register some StepListeners with the handler. Each will get the callbacks in the order specified at the correct stage.

Parameters:

listeners - list of listeners to be used within this step

registerListener

public void registerListener(StepListener listener)

Register a listener for callbacks at the appropriate stages in a process.

Parameters:

listener - a StepListener

provide

protected I provide(StepContribution contribution,
                    Chunk<I> chunk)
             throws java.lang.Exception

Responsible for the reading portion of the chunking loop. In this implementation, delegates to doProvide(StepContribution, Chunk)

Parameters:

contribution - a StepContribution

chunk - a Chunk

Returns:

an item

Throws:

java.lang.Exception - thrown if error occurs during the reading portion of the chunking loop.

doProvide

protected final I doProvide(StepContribution contribution,
                            Chunk<I> chunk)
                     throws java.lang.Exception

Implements reading as well as any related listener calls required.

Parameters:

contribution - a StepContribution

chunk - a Chunk

Returns:

an item

Throws:

java.lang.Exception - thrown if error occurs during reading or listener calls.

transform

protected O transform(StepContribution contribution,
                      I item)
               throws java.lang.Exception

Responsible for the processing portion of the chunking loop. In this implementation, delegates to the doTransform(Object) if a processor is available (returns the item unmodified if it is not)

Parameters:

contribution - a StepContribution

item - an item

Returns:

a processed item if a processor is present (the unmodified item if it is not)

Throws:

java.lang.Exception - thrown if error occurs during the processing portion of the chunking loop.

doTransform

protected final O doTransform(I item)
                       throws java.lang.Exception

Implements processing and all related listener calls.

Parameters:

item - the item to be processed

Returns:

the processed item

Throws:

java.lang.Exception - thrown if error occurs during processing.

persist

protected void persist(StepContribution contribution,
                       Chunk<O> chunk)
                throws java.lang.Exception

Responsible for the writing portion of the chunking loop. In this implementation, delegates to the {doPersist(StepContribution, Chunk).

Parameters:

contribution - a StepContribution

chunk - a Chunk

Throws:

java.lang.Exception - thrown if error occurs during the writing portion of the chunking loop.

doPersist

protected final void doPersist(StepContribution contribution,
                               Chunk<O> chunk)
                        throws java.lang.Exception

Implements writing and all related listener calls

Parameters:

contribution - a StepContribution

chunk - a Chunk

Throws:

java.lang.Exception - thrown if error occurs during the writing portion of the chunking loop.