org.springframework.batch.jsr.item

Class ItemReaderAdapter<T>

java.lang.Object

org.springframework.batch.item.ItemStreamSupport

org.springframework.batch.jsr.item.CheckpointSupport

org.springframework.batch.jsr.item.ItemReaderAdapter<T>

All Implemented Interfaces:

ItemReader<T>, ItemStream

public class ItemReaderAdapter<T>
extends CheckpointSupport
implements ItemReader<T>

Adapter that wraps an ItemReader for use by Spring Batch. All calls are delegated as appropriate to the corresponding method on the delegate.

Since:

3.0

Author:

Michael Minella

Constructor Summary

Constructors

Constructor and Description
ItemReaderAdapter(javax.batch.api.chunk.ItemReader reader)

Method Summary

Modifier and Type	Method and Description
protected java.io.Serializable	doCheckpoint() Used to provide a Serializable representing the current state of the batch artifact.
protected void	doClose() Used to close the underlying batch artifact
protected void	doOpen(java.io.Serializable checkpoint) Used to open a batch artifact with previously saved checkpoint information.
T	read() Reads a piece of input data and advance to the next one.

Methods inherited from class org.springframework.batch.jsr.item.CheckpointSupport

close, open, update

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

getExecutionContextKey, getName, setExecutionContextName, setName

Methods inherited from class java.lang.Object

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

Constructor Detail

ItemReaderAdapter

public ItemReaderAdapter(javax.batch.api.chunk.ItemReader reader)

Parameters:

reader - the ItemReader implementation to delegate to

Method Detail

read

@Nullable
public T read()
                 throws java.lang.Exception

Description copied from interface: ItemReader

Reads a piece of input data and advance to the next one. Implementations must return null at the end of the input data set. In a transactional setting, caller might get the same item twice from successive calls (or otherwise), if the first call was in a transaction that rolled back.

Specified by:

read in interface ItemReader<T>

Returns:

T the item to be processed or null if the data source is exhausted

Throws:

ParseException - if there is a problem parsing the current record (but the next one may still be valid)

NonTransientResourceException - if there is a fatal exception in the underlying resource. After throwing this exception implementations should endeavour to return null from subsequent calls to read.

UnexpectedInputException - if there is an uncategorised problem with the input data. Assume potentially transient, so subsequent calls to read might succeed.

java.lang.Exception - if an there is a non-specific error.

doClose

protected void doClose()
                throws java.lang.Exception

Description copied from class: CheckpointSupport

Used to close the underlying batch artifact

Specified by:

doClose in class CheckpointSupport

Throws:

java.lang.Exception - thrown by the underlying implementation

doCheckpoint

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

Description copied from class: CheckpointSupport

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

Specified by:

doCheckpoint in class CheckpointSupport

Returns:

the current state of the batch artifact

Throws:

java.lang.Exception - thrown by the implementation

doOpen

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

Description copied from class: CheckpointSupport

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

Specified by:

doOpen in class CheckpointSupport

Parameters:

checkpoint - previously saved checkpoint object

Throws:

java.lang.Exception - thrown by the implementation