org.springframework.batch.jsr.item

Class CheckpointSupport

java.lang.Object

org.springframework.batch.item.ItemStreamSupport

org.springframework.batch.jsr.item.CheckpointSupport

All Implemented Interfaces:

ItemStream

Direct Known Subclasses:

ItemReaderAdapter, ItemWriterAdapter

public abstract class CheckpointSupport
extends ItemStreamSupport

Provides support for JSR-352 checkpointing. Checkpoint objects are copied prior to being added to the ExecutionContext for persistence by the framework. If the checkpoint object cannot be copied and further changes occur to the same instance, side effects may occur. In cases like this, it is recommended that a copy of the object being acted upon in the reader/writer is returned via the ItemReader.checkpointInfo() or ItemWriter.checkpointInfo() calls.

Since:

3.0

Author:

Michael Minella

Constructor Summary

Constructors

Constructor and Description
CheckpointSupport(java.lang.String checkpointKey)

Method Summary

Modifier and Type	Method and Description
void	close() No-op.
protected abstract java.io.Serializable	doCheckpoint() Used to provide a Serializable representing the current state of the batch artifact.
protected abstract void	doClose() Used to close the underlying batch artifact
protected abstract void	doOpen(java.io.Serializable checkpoint) Used to open a batch artifact with previously saved checkpoint information.
void	open(ExecutionContext executionContext) No-op.
void	update(ExecutionContext executionContext) Return empty ExecutionContext.

Methods inherited from class org.springframework.batch.item.ItemStreamSupport

getExecutionContextKey, setExecutionContextName, setName

Methods inherited from class java.lang.Object

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

Constructor Detail

CheckpointSupport

public CheckpointSupport(java.lang.String checkpointKey)

Parameters:

checkpointKey - key to store the checkpoint object with in the ExecutionContext

Method Detail

open

public void open(ExecutionContext executionContext)
          throws ItemStreamException

Description copied from class: ItemStreamSupport

No-op.

Specified by:

open in interface ItemStream

Overrides:

open in class ItemStreamSupport

Parameters:

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

Throws:

ItemStreamException

See Also:

ItemStream.open(ExecutionContext)

doOpen

protected abstract void doOpen(java.io.Serializable checkpoint)
                        throws java.lang.Exception

Used to open a batch artifact with previously saved checkpoint information.

Parameters:

checkpoint - previously saved checkpoint object

Throws:

java.lang.Exception - thrown by the implementation

update

public void update(ExecutionContext executionContext)
            throws ItemStreamException

Description copied from class: ItemStreamSupport

Return empty ExecutionContext.

Specified by:

update in interface ItemStream

Overrides:

update in class ItemStreamSupport

Parameters:

executionContext - to be updated

Throws:

ItemStreamException

See Also:

ItemStream.update(ExecutionContext)

doCheckpoint

protected abstract java.io.Serializable doCheckpoint()
                                              throws java.lang.Exception

Used to provide a Serializable representing the current state of the batch artifact.

Returns:

the current state of the batch artifact

Throws:

java.lang.Exception - thrown by the implementation

close

public void close()
           throws ItemStreamException

Description copied from class: ItemStreamSupport

No-op.

Specified by:

close in interface ItemStream

Overrides:

close in class ItemStreamSupport

Throws:

ItemStreamException

See Also:

ItemStream.close()

doClose

protected abstract void doClose()
                         throws java.lang.Exception

Used to close the underlying batch artifact

Throws:

java.lang.Exception - thrown by the underlying implementation