org.springframework.batch.item.file
Class MultiResourceItemWriter<T>

java.lang.Object
  org.springframework.batch.item.util.ExecutionContextUserSupport
      org.springframework.batch.item.file.MultiResourceItemWriter<T>

Type Parameters:

T - item type

All Implemented Interfaces:

ItemStream, ItemWriter<T>

public class MultiResourceItemWriter<T>
extends ExecutionContextUserSupport
implements ItemWriter<T>, ItemStream

Wraps a ResourceAwareItemWriterItemStream and creates a new output resource when the count of items written in current resource exceeds setItemCountLimitPerResource(int). Suffix creation can be customized with setResourceSuffixCreator(ResourceSuffixCreator). Note that new resources are created only at chunk boundaries i.e. the number of items written into one resource is between the limit set by setItemCountLimitPerResource(int) and (limit + chunk size).

Author:

Robert Kasanicky

Constructor Summary

MultiResourceItemWriter()

Method Summary

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(ResourceAwareItemWriterItemStream<? super T> delegate) Delegate used for actual writing of the output.
void	setItemCountLimitPerResource(int itemCountLimitPerResource) After this limit is exceeded the next chunk will be written into newly created resource.
void	setResource(Resource resource) Prototype for output resources.
void	setResourceSuffixCreator(ResourceSuffixCreator suffixCreator) Allows customization of the suffix of the created resources based on the index.
void	setSaveState(boolean saveState)
void	update(ExecutionContext executionContext) Indicates that the execution context provided during open is about to be saved.
void	write(List<? extends T> items) Process the supplied data element.

Methods inherited from class org.springframework.batch.item.util.ExecutionContextUserSupport

getKey, getName, setName

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiResourceItemWriter

public MultiResourceItemWriter()

Method Detail

write

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

Description copied from interface: ItemWriter

Process the supplied data element. Will not be called with any null items in normal operation.

Specified by:

write in interface ItemWriter<T>

Throws:

Exception - if there are errors. The framework will catch the exception and convert or rethrow it as appropriate.

setResourceSuffixCreator

public void setResourceSuffixCreator(ResourceSuffixCreator suffixCreator)

Allows customization of the suffix of the created resources based on the index.

setItemCountLimitPerResource

public void setItemCountLimitPerResource(int itemCountLimitPerResource)

After this limit is exceeded the next chunk will be written into newly created resource.

setDelegate

public void setDelegate(ResourceAwareItemWriterItemStream<? super T> delegate)

Delegate used for actual writing of the output.

setResource

public void setResource(Resource resource)

Prototype for output resources. Actual output files will be created in the same directory and use the same name as this prototype with appended suffix (according to setResourceSuffixCreator(ResourceSuffixCreator).

setSaveState

public void setSaveState(boolean saveState)

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

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

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