org.springframework.batch.core.step.item
Class Chunk<W>

java.lang.Object
  org.springframework.batch.core.step.item.Chunk<W>

All Implemented Interfaces:

Iterable<W>

public class Chunk<W>
extends Object
implements Iterable<W>

Encapsulation of a list of items to be processed and possibly a list of failed items to be skipped. To mark an item as skipped clients should iterate over the chunk using the iterator() method, and if there is a failure call Chunk.ChunkIterator.remove() on the iterator. The skipped items are then available through the chunk.

Since:

2.0

Author:

Dave Syer

Nested Class Summary

class

Chunk.ChunkIterator Special iterator for a chunk providing the #remove(Exception) method for dynamically removing an item and adding it to the skips.

Constructor Summary

Chunk()

Chunk(Collection<? extends W> items)

Chunk(Collection<? extends W> items, List<SkipWrapper<W>> skips)

Method Summary

void	add(W item) Add the item to the chunk.
void	clear() Clear the items down to signal that we are done.
void	clearSkips() Clear only the skips list.
List<Exception>	getErrors()
List<W>	getItems()
List<SkipWrapper<W>>	getSkips()
Object	getUserData()
boolean	isBusy() Query the chunk to see if anyone has registered an interest in keeping a reference to it.
boolean	isEmpty()
boolean	isEnd() Flag to indicate if the source data is exhausted.
Chunk.ChunkIterator	iterator() Get an unmodifiable iterator for the underlying items.
void	setBusy(boolean busy) Register an interest in the chunk to prevent it from being cleaned up before the flag is reset to false.
void	setEnd() Set the flag to say that this chunk represents an end of stream (there is no more data to process).
void	setUserData(Object userData)
int	size()
void	skip(Exception e) Register an anonymous skip.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Chunk

public Chunk()

Chunk

public Chunk(Collection<? extends W> items)

Chunk

public Chunk(Collection<? extends W> items,
             List<SkipWrapper<W>> skips)

Method Detail

add

public void add(W item)

Add the item to the chunk.

Parameters:

item -

clear

public void clear()

Clear the items down to signal that we are done.

getItems

public List<W> getItems()

Returns:

a copy of the items to be processed as an unmodifiable list

getSkips

public List<SkipWrapper<W>> getSkips()

Returns:

a copy of the skips as an unmodifiable list

getErrors

public List<Exception> getErrors()

Returns:

a copy of the anonymous errros as an unmodifiable list

skip

public void skip(Exception e)

Register an anonymous skip. To skip an individual item, use Chunk.ChunkIterator.remove().

Parameters:

e - the exception that caused the skip

isEmpty

public boolean isEmpty()

Returns:

true if there are no items in the chunk

iterator

public Chunk.ChunkIterator iterator()

Get an unmodifiable iterator for the underlying items.

Specified by:

iterator in interface Iterable<W>

See Also:

Iterable.iterator()

size

public int size()

Returns:

the number of items (excluding skips)

isEnd

public boolean isEnd()

Flag to indicate if the source data is exhausted.

Returns:

true if there is no more data to process

setEnd

public void setEnd()

Set the flag to say that this chunk represents an end of stream (there is no more data to process).

isBusy

public boolean isBusy()

Query the chunk to see if anyone has registered an interest in keeping a reference to it.

Returns:

the busy flag

setBusy

public void setBusy(boolean busy)

Register an interest in the chunk to prevent it from being cleaned up before the flag is reset to false.

Parameters:

busy - the flag to set

clearSkips

public void clearSkips()

Clear only the skips list.

getUserData

public Object getUserData()

setUserData

public void setUserData(Object userData)

toString

public String toString()

Overrides:

toString in class Object