com.amazonaws.services.dynamodbv2.document

Class ItemCollection<R>

java.lang.Object

com.amazonaws.services.dynamodbv2.document.internal.PageBasedCollection<Item,R>

com.amazonaws.services.dynamodbv2.document.ItemCollection<R>

Type Parameters:

R - low level result type

All Implemented Interfaces:

Iterable<Item>

public abstract class ItemCollection<R>
extends PageBasedCollection<Item,R>

A collection of Item's. An ItemCollection object maintains a cursor pointing to its current pages of data. Initially the cursor is positioned before the first page. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ItemCollection object, it can be used in a while loop to iterate through the collection. Network calls can be triggered when the collection is iterated across page boundaries.

Constructor Summary

Constructors

Constructor and Description
ItemCollection()

Method Summary

Modifier and Type	Method and Description
protected void	accumulateStats(ConsumedCapacity consumedCapacity, Integer count, Integer scannedCount)
ConsumedCapacity	getAccumulatedConsumedCapacity() Returns the consumed capacity accumulated so far.
int	getAccumulatedItemCount() Returns the count of items accumulated so far.
int	getAccumulatedScannedCount() Returns the scanned count accumulated so far.
R	getLastLowLevelResult() Returns the low-level result last retrieved (for the current page) from the server side; or null if there has yet no calls to the server.
abstract Integer	getMaxResultSize() Returns the maximum number of resources to be retrieved in this collection; or null if there is no limit.
ConsumedCapacity	getTotalConsumedCapacity() Deprecated. This method returns the accumulated consumed capacity and not the total. Use getAccumulatedScannedCount() instead.
int	getTotalCount() Deprecated. This method returns the accumulated count and not the total count. Use getAccumulatedItemCount() instead.
int	getTotalScannedCount() Deprecated. This method returns the accumulated count and not the total count. Use getAccumulatedScannedCount() instead.
PageIterable<Item,R>	pages() Returns an Iterable<Page<Item, R>> that iterates over pages of items from this collection.
LowLevelResultListener<R>	registerLowLevelResultListener(LowLevelResultListener<R> listener) Used to register a listener for the event of receiving a low-level result from the server side.

Methods inherited from class com.amazonaws.services.dynamodbv2.document.internal.PageBasedCollection

firstPage, iterator, setLastLowLevelResult

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ItemCollection

public ItemCollection()

Method Detail

accumulateStats

protected final void accumulateStats(ConsumedCapacity consumedCapacity,
                                     Integer count,
                                     Integer scannedCount)

getTotalCount

@Deprecated
public int getTotalCount()

Deprecated. This method returns the accumulated count and not the total count. Use getAccumulatedItemCount() instead.

Returns the count of items accumulated so far.

getAccumulatedItemCount

public int getAccumulatedItemCount()

Returns the count of items accumulated so far.

getTotalScannedCount

@Deprecated
public int getTotalScannedCount()

Deprecated. This method returns the accumulated count and not the total count. Use getAccumulatedScannedCount() instead.

Returns the scanned count accumulated so far.

getAccumulatedScannedCount

public int getAccumulatedScannedCount()

Returns the scanned count accumulated so far.

getTotalConsumedCapacity

@Deprecated
public ConsumedCapacity getTotalConsumedCapacity()

Deprecated. This method returns the accumulated consumed capacity and not the total. Use getAccumulatedScannedCount() instead.

Returns the consumed capacity accumulated so far.

getAccumulatedConsumedCapacity

public ConsumedCapacity getAccumulatedConsumedCapacity()

Returns the consumed capacity accumulated so far.

pages

public PageIterable<Item,R> pages()

Returns an Iterable<Page<Item, R>> that iterates over pages of items from this collection. Each call to Iterator.next on an Iterator returned from this Iterable results in exactly one call to DynamoDB to retrieve a single page of results.

ItemCollection<QueryResult> collection = ...; for (Page<Item> page : collection.pages()) { processItems(page); ConsumedCapacity consumedCapacity = page.getLowLevelResult().getConsumedCapacity(); Thread.sleep(getBackoff(consumedCapacity.getCapacityUnits())); }

The use of the internal/undocumented PageIterable class instead of Iterable in the public interface here is retained for backwards compatibility. It doesn't expose any methods beyond those of the Iterable interface. This method will be changed to return an Iterable<Page<Item, R>> directly in a future release of the SDK.

Overrides:

pages in class PageBasedCollection<Item,R>

See Also:

Page

getMaxResultSize

public abstract Integer getMaxResultSize()

Returns the maximum number of resources to be retrieved in this collection; or null if there is no limit.

Specified by:

getMaxResultSize in class PageBasedCollection<Item,R>

getLastLowLevelResult

public R getLastLowLevelResult()

Returns the low-level result last retrieved (for the current page) from the server side; or null if there has yet no calls to the server.

Overrides:

getLastLowLevelResult in class PageBasedCollection<Item,R>

registerLowLevelResultListener

public LowLevelResultListener<R> registerLowLevelResultListener(LowLevelResultListener<R> listener)

Used to register a listener for the event of receiving a low-level result from the server side.

Overrides:

registerLowLevelResultListener in class PageBasedCollection<Item,R>

Parameters:

listener - listener to be registered. If null, a "none" listener will be set.

Returns:

the previously registered listener. The return value is never null.