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 com.amazonaws.services.dynamodbv2.document.internal.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

Methods

Modifier and Type	Method and Description
protected void	accumulateStats(ConsumedCapacity consumedCapacity, Integer count, Integer scannedCount)
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() Returns the total consumed capacity accumulated so far.
int	getTotalCount() Returns the total count accumulated so far.
int	getTotalScannedCount() Returns the total scanned count accumulated so far.
com.amazonaws.services.dynamodbv2.document.internal.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

Constructor Detail

ItemCollection

public ItemCollection()

Method Detail

accumulateStats

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

getTotalCount

public int getTotalCount()

Returns the total count accumulated so far.

getTotalScannedCount

public int getTotalScannedCount()

Returns the total scanned count accumulated so far.

getTotalConsumedCapacity

public ConsumedCapacity getTotalConsumedCapacity()

Returns the total consumed capacity accumulated so far.

pages

public com.amazonaws.services.dynamodbv2.document.internal.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 com.amazonaws.services.dynamodbv2.document.internal.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 com.amazonaws.services.dynamodbv2.document.internal.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 com.amazonaws.services.dynamodbv2.document.internal.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 com.amazonaws.services.dynamodbv2.document.internal.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.