Package org.springframework.batch.integration.async

Class AsyncItemWriter<T>

java.lang.Object

org.springframework.batch.integration.async.AsyncItemWriter<T>

All Implemented Interfaces:

ItemStream, ItemStreamWriter<Future<T>>, ItemWriter<Future<T>>

public class AsyncItemWriter<T>
extends Object
implements ItemStreamWriter<Future<T>>

Constructor Summary

Constructors

Constructor	Description
AsyncItemWriter(ItemWriter<T> delegate)	Create a new instance of AsyncItemWriter with the provided delegate.

Method Summary

Modifier and Type	Method	Description
void	close()	If any resources are needed for the stream to operate they need to be destroyed here.
void	open(ExecutionContext executionContext)	Open the stream for the provided ExecutionContext.
void	setDelegate(ItemWriter<T> delegate)
void	update(ExecutionContext executionContext)	Indicates that the execution context provided during open is about to be saved.
void	write(Chunk<? extends Future<T>> items)	In the processing of the Futures passed, nulls are not passed to the delegate since they are considered filtered out by the AsyncItemProcessor's delegated ItemProcessor.

Methods inherited from class java.lang.Object

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

Constructor Details

AsyncItemWriter

public AsyncItemWriter(ItemWriter<T> delegate)

Create a new instance of AsyncItemWriter with the provided delegate.

Parameters:

delegate - the delegate item writer

Since:

6.0

Method Details

setDelegate

public void setDelegate(ItemWriter<T> delegate)

Parameters:

delegate - ItemWriter that does the actual writing of the Future results

write

public void write(Chunk<? extends Future<T>> items)
           throws Exception

In the processing of the Futures passed, nulls are not passed to the delegate since they are considered filtered out by the AsyncItemProcessor's delegated ItemProcessor. If the unwrapping of the Future results in an ExecutionException, that will be unwrapped and the cause will be thrown.

Specified by:

write in interface ItemWriter<T>

Parameters:

items - Futures to be unwrapped and passed to the delegate

Throws:

Exception - The exception returned by the Future if one was thrown

open

public void open(ExecutionContext executionContext)
          throws ItemStreamException

Description copied from interface: ItemStream

Open the stream for the provided ExecutionContext.

Specified by:

open in interface ItemStream

Parameters:

executionContext - current step's ExecutionContext. Will be the executionContext from the last run of the step on a restart.

Throws:

ItemStreamException

update

public void update(ExecutionContext executionContext)
            throws ItemStreamException

Description copied from interface: ItemStream

Indicates that the execution context provided during open is about to be saved. If any state is remaining, but has not been put in the context, it should be added here.

Specified by:

update in interface ItemStream

Parameters:

executionContext - to be updated

Throws:

ItemStreamException

close

public void close()
           throws ItemStreamException

Description copied from interface: ItemStream

If any resources are needed for the stream to operate they need to be destroyed here. Once this method has been called all other methods (except open) may throw an exception.

Specified by:

close in interface ItemStream

Throws:

ItemStreamException